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MOPMF047 Transverse Coupling Measurements With High Intensity Beams Using Driven Oscillations coupling, dipole, injection, resonance 208
 
  • T. Persson, G. Baud, X. Buffat, J.M. Coello de Portugal, E. Fol, K. Fuchsberger, M. Gabriel, M. Gąsior, M. Giovannozzi, G.H. Hemelsoet, M. Hostettler, M. Hruska, D. Jacquet, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, M. Solfaroli Camillocci, M.E. Söderén, R. Tomás, D. Valuch, A. Wegscheider, J. Wenninger
    CERN, Geneva, Switzerland
 
  Transverse coupling has been linked to instabilities and reduction in dynamic aperture and is hence a crucial parameter to control in the LHC. In this article we describe the development to use driven oscillations to measure the transverse coupling with high intensity beams. The method relies on the use of the transverse damper to drive an oscillation in a similar way as with an AC-dipole. The calculation of the coupling is based on the turn-by-turn data from all available BPMs gated for the excited bunch.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF047  
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MOPMF060 Safe Disposal of the LHC Beam without Beam Dump - Method and Experimental Verification experiment, collimation, emittance, dumping 253
 
  • M. Valette, B. Lindstrom, A. Mereghetti, R. Schmidt, M. Solfaroli, J.A. Uythoven, D. Valuch, J. Wenninger, D. Wollmann, M. Zerlauth
    CERN, Geneva, Switzerland
 
  Funding: Research supported by the HL-LHC project.
In the extremely unlikely event of a non-working beam dumping system in the LHC, the 360 MJ of stored beam energy can be dissipated in the collimation system as a last mitigation measure. In such a situation, it is important to reduce the stored beam energy both quickly and at the same time as smoothly as possible in order to limit the risk of trips of critical systems, to avoid quenches of superconducting magnets (which would lead to changes of the beam trajectory and damage to the accelerator) and ultimately damage to the collimators themselves. Detailed steps and parameters have been developed and validated during two dedicated experiments with beam in the LHC. This paper summarizes the key aspects in view of the preparation of such a procedure for operational use, which will allow for the safe disposal of the full LHC beam by the operation crews.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF060  
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MOPMF088 Preparation Activity for the Siddharta-2 Run at DAΦNE experiment, luminosity, feedback, quadrupole 334
 
  • C. Milardi, D. Alesini, S. Bini, O.R. Blanco-García, M. Boscolo, B. Buonomo, S. Cantarella, S. Caschera, A. D'Uffizi, A. De Santis, G.O. Delle Monache, D.G.C. Di Giulio, G. Di Pirro, A. Drago, L.G. Foggetta, A. Gallo, R. Gargana, A. Ghigo, S. Guiducci, S. Incremona, F. Iungo, C. Ligi, M. Maestri, A. Michelotti, L. Pellegrino, R. Ricci, U. Rotundo, L. Sabbatini, C. Sanelli, G. Sensolini, A. Stecchi, A. Stella, A. Vannozzi, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  • G. Castorina
    INFN-Roma1, Rome, Italy
  • J. Chavanne, G. Le Bec, P. Raimondi
    ESRF, Grenoble, France
 
  DAΦNE, the Frascati lepton collider working at the c.m. energy of the F resonance, continues to be a very suitable infrastructure to realize experiments aimed at studying elementary particles and nuclear physics. The motivations of this long lasting interest are related to the DAΦNE ability of increasing its performances in terms of luminosity thanks to the innovative Crab-Waist collision scheme. In this framework, a new run for the SIDDHARTA-2 experiment has been planned in the year 2019. The detector presently installed in the interaction region, KLOE-2, will be removed and a new low-beta session, equipped with new permanent magnets quadrupoles, will be installed. Diagnostics tools will be improved especially the ones used to keep under control the beam-beam interaction. The horizontal feedback in the positron ring will be potentiated in order to achieve a higher positron current. The design and development work done in view of the SIDDHARTA-2 run is presented and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF088  
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MOPML030 Demonstration of a Tunable Electron Beam Chopper for Application in 200 kV stroboscopic TEM electron, kicker, laser, experiment 467
 
  • C.-J. Jing, S.V. Baryshev, A. Kanareykin, A. Liu, Y. Zhao
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • J.W. Lau
    NIST, Gaithersburg, Maryland, USA
  • D. Masiel, B. Reed
    Integrated Dynamic Electron Solutions, Pleasanton, California, USA
  • Y. Zhu
    BNL, Upton, Long Island, New York, USA
 
  Funding: The project is supported by the Office of Basic Energy Science of DOE through a Small Business Innovative Research grant #DE-SC0013121.
For the last several decades, time-resolved transmission electron microscopes (TEM) exploring the sub-microsecond timescale have relied on the photoemission technology to generate the single or train of electron bunches. However, the complexity of additional laser system and the availability of high repitition rate laser limit applications of the laser-driven approach. Lately we have made substantial progress towards pioneering a new kind of time-resolved TEM, complementary to the existing laser-based techniques. Using a tunable RF beam-chopper, we are able to retrofit an exsiting TEM providing a pulsed electron beam at a continuously tunable reptition rate up to 12GHz and a tunable bunch length. In the article we will briefly discuss the working principle and experimental progress to date.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML030  
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MOPML033 Data Supply of Accelerator Devices - Data Management of Device Process Data at a Medical Accelerator database, operation, MMI, linac 477
 
  • M. Galonska, R. Cee, Th. Haberer, K. Höppner, J.M. Mosthaf, A. Peters, S. Scheloske, C. Schömers
    HIT, Heidelberg, Germany
 
  HIT is the first dedicated proton and carbon cancer therapy facility in Europe. It uses the full 3D intensity controlled raster scanning dose delivery method of pencil beams with ion beams of 48 - 430 MeV/u provided by a linac-synchrotron-system. Ion beams in this wide range of energies, different beam sizes, and intensities have to be provided by the control system to all treatment rooms at any time with high accuracy, stability, and reproducibility. This paper briefly reflects some aspects of the data supply, i. e. the settings of accelerator devices at a medical accelerator. This includes the generation of control data, storage, and data recovery routines, which have been developed at HIT in the recent years. That is in particular the management of verified therapy data and settings, which are stored in a non-volatile memory of the device controllers, and – as a backup – in a database and which are protected against unintended changes for safety reasons.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML033  
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MOPML054 Production and Collection of He-3 and Other Valuable Isotopes using Mu*STAR simulation, proton, MMI, interface 527
 
  • R.P. Johnson, R.J. Abrams, M.A. Cummings, T.J. Roberts
    Muons, Inc, Illinois, USA
 
  We propose an example facility based on GEM*STAR, an accelerator-driven molten-salt-fueled graphite-moderated thermal-spectrum reactor that can operate with different fissile fuels and uses a LiF-BeF2 molten eutectic carrier salt. In the first example, they propose using the 6Li in the LiF carrier to produce more than 2 kg/y of tritium (decaying to 3He with 12.3 year half-life) using a 2.5 MWb superconducting proton linac to drive the subcritical 500 MWt reactor burning surplus plutonium. The collection of other valuable fission-product radioisotopes like 133Xe will also benefit from the high temperature and continuous removal and separation afforded by fractional distillation  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML054  
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MOPML058 Comparison of Water Absorbed Dose for Photons of Linac and Traceability System for Radiotherapy in China photon, radiation, linac, electron 537
 
  • K. Wang, S. Jin, Z. Wang, J. Zhang
    National Institute of Metrology, Beijing, People's Republic of China
 
  National Institute of Metrology (NIM) developed the standards of the absorbed dose to water for high-energy photon and electron beams, to support the PSDL and SSDL calibration capability in China. After the measurement of absorbed dose to water for 6, 10, and 25 MV photons of linac, NIM took part the BIPM. RI(I).K6 comparison with the Bureau International des Poids et Mesures (BIPM). The tissue phantom ratio (TPR20,10) of 6MV and 10MV photons were measured by IBA CC13 chamber and Keithley 6517B with different output dose of the Linac, and also calculated by the dose ratio (D20⁄D10) with the formula in IAEA TRS-398 report. TPR20,10 measured directly is 0.3% larger than calculated by the dose ratio D20⁄D10 . The absorbed dose to water is measured by water calorimeter with the combined standard uncertainty of 0.35%. The discrepancy of absorbed dose to water measured separately by open and sealed vessel is 0.2% at 10MV. The K6 comparison was done, the results reported as ratios of the NIM and the BIPM evaluations (and with the combined standard uncertainties given in parentheses), are 0.9917(60) at 6 MV, and 0.9941(59) at 10 MV. The quality correction factor KQ of usual used chamber was measure directly, and it is 0.3%~0.7% smaller than the data in the IAEA TRS-398 report. The typical chamber-to-chamber variations of the dose obtained with the IAEA TRS-277, TRS-398 and AAPM TG-51 were between 0.2% and 1.0% for the different photon beams. The variations of the dose obtained with IAEA TRS-398 and chambers calibrated directly by megavoltage photons were between 0.1% to 0.8%. The new standard can achieve the traceability of water absorbed dose for MV photons and will significantly reduce the uncertainty of ion chamber calibrations for Chinese radiotherapy centers.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML058  
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MOPML059 Precise Beam Delivery for Proton Therapy with Dynamic Energy Modulation proton, target, radiation, MMI 540
 
  • O. Actis, A. Mayor, D. Meer, D.C. Weber
    PSI, Villigen PSI, Switzerland
  • D.C. Weber
    University of Zurich, University Hospital, Zurich, Switzerland
 
  Gantry 2 at PSI is a Pencil Beam Scanning (PBS) cyclotron based proton therapy system. PBS proved to be an effective treatment method for static tumors but for mobile targets (e.g lung) organ motion interferes with beam delivery lowering the treatment quality. A method to mitigate motion effects is to re-scan the treatment volume multiple times. The downside of re-scanning is the increase of treatment time due to high number of energy switches and magnet initializations (ramping) between scans. Our current re-scanning implementation is performed with a decreasing energy sequence and takes about 6s/scan thanks to fast energy switching of 100ms. Ramping adds 8s more leading to a treatment time of >60s. We developed beam line settings for reverse energy sequence and removed the full ramping between scans. This dynamic beam delivery leads to non-negligible beam position errors of >1.5mm which we compensate by field specific corrections. Using a patient file we proved that our novel re-scanning concept doubles the treatment efficiency. Using in-house developed measurement equipment we obtained a precision of <0.5mm in position and <1mm in range which fulfills all clinical requirements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML059  
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TUXGBD1 Potential and Issues for Future Accelerators and Ultimate Colliders emittance, photon, synchrotron, laser 578
 
  • S.J. Brooks
    BNL, Upton, Long Island, New York, USA
 
  Particle colliders have been remarkably successful tools in particle and nuclear physics. What are the future trends and limitations of accelerators as they currently exist, and are there possible alternative approaches? What would the ultimate collider look like? This talk examines some challenges and possible solutions. Accelerating a single particle rather than a thermal distribution may allow exploration of more controlled interactions without background. Also, cost drivers are possibly the most important limiting factor for large accelerators in the foreseeable future so emerging technologies to reduce cost are highlighted.  
slides icon Slides TUXGBD1 [2.590 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUXGBD1  
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TUPAF003 Integrated Prototyping in View of the 100 MeV Linac for Myrrha Phase 1 linac, cryomodule, cavity, target 661
 
  • D. Vandeplassche, J. Belmans
    SCK•CEN, Mol, Belgium
  • C. Angulo, D. Davin, W. De Cock, P. Della Faille, F. Doucet, A. Gatera, Pompon, F.F. Pompon
    Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium
  • D. Bondoux, F. Bouly
    LPSC, Grenoble Cedex, France
  • H. Höltermann, D. Mäder
    BEVATECH, Frankfurt, Germany
  • C. Joly, G. Olry, H. Saugnac
    IPN, Orsay, France
  • M. Loiselet, N. Postiau, L. Standaert
    UCL, Louvain-la-Neuve, Belgium
  • H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  Funding: Work partially supported by the European Commission H2020 programme MYRTE #662186
The MYRRHA project borne by SCK•CEN, the Belgian Nuclear Research Centre, aims at realizing a pre-industrial Accelerator Driven System (ADS) for exploring the transmutation of long lived nuclear waste. The linac for this ADS will be a High Power Proton Accelerator delivering 2.4 MW CW beam at 600 MeV. It has to satisfy stringent requirements for reliability and availability: a beam-MTBF of 250h is targeted. The reliability goal is pursued through a phased approach. During Phase 1, expected till 2024, the MYRRHA linac up to 100 MeV will be constructed. It will allow to evaluate the reliability potential of the 600 MeV linac. It will also feed a Proton Target Facility in which radioisotopes of interest will be collected through an ISOL system. This contribution will focus on the transition to integrated prototyping, which will emphasize (i) a test platform consisting of the initial section of the normal conducting injector (5.9 MeV), (ii) the realization of a complete cryomodule for the superconducting linac and of its cryogenic valve box. The cryomodule will house two 352 MHz single spoke cavities operated at 2K.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF003  
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TUPAF012 Commissioning of the Lipac Medium Energy Beam Transport Line cavity, vacuum, rfq, operation 683
 
  • I. Podadera, J. Castellanos, J.M. García, D. Gavela, A. Ibarra, D. Jiménez-Rey, A. Marqueta, L.M. Martinez Fresno, E. Molina Marinas, J. Mollá, P. Méndez, C. Oliver, D. Regidor, F. Toral, R. Varela, V. Villamayor, M. Weber, C. de la Morena
    CIEMAT, Madrid, Spain
  • P. Cara, A. Marqueta, I. Moya
    Fusion for Energy, Garching, Germany
  • T. Ebisawa, Y. Hirata, A. Ihara, Y. Ikeda, A. Kasugai, T. Kitano, K. Kondo, T. Narita, K. Sakamoto, T. Shinya, M. Sugimoto
    QST, Aomori, Japan
  • D. Gex, A. Jokinen
    F4E, Germany
  • J. Knaster
    IFMIF/EVEDA, Rokkasho, Japan
  • M. Mendez Macias
    7S, Peligros (Granada), Spain
  • O. Nomen
    IREC, Sant Adria del Besos, Spain
  • G. Pruneri
    Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova, Italy
  • F. Scantamburlo
    INFN/LNL, Legnaro (PD), Italy
 
  Funding: This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Agreement as published in BOE, 16/01/2013, page 1988 and the project FIS2013-40860-R.
LIPAc* will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology to be used as neutron source of the IFMIF facility. Those facilities are essential for future fusion reactors material research. A 175 MHz RFQ will increase the energy up to 5 MeV before a Superconducting RF (SRF) linac with eight 175 MHz Half Wave Resonators brings the particles up to the final energy of 9 MeV. Between both stages, a Medium Energy Beam Transport line (MEBT)** aims at transporting and matching the beam between the RFQ and the SRF linac. The transverse focusing of the beam is controlled by five quadrupole magnets with integrated steerers, grouped in one triplet and one doublet. Two buncher cavities handle the longitudinal dynamics. Two movable scraper systems are included to purify the beam optics coming out the RFQ and avoid losses in the SRF linac. In this contribution, checkout of the beamline and its ancillaries in Japan is reported. Tests carried out on the beamline prior to the MEBT beam commissioning are described, focusing in vacuum tests, magnets powering, buncher conditioning and scrapers movement.
* P. Cara et al., IPAC16, MOPOY057 , p.985, Busan, Korea (2016)
** I. Podadera et al., LINAC2016, TUPLR041, p.554, East Lansing, USA (2016).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF012  
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TUPAF018 Characterization of Automatic Frequency Control systems for S-band Proton LINAC "TOP-IMPLART" DTL, proton, linac, detector 701
 
  • G. Bazzano, P. Nenzi, L. Picardi, C. Ronsivalle, M. Vadrucci
    ENEA C.R. Frascati, Frascati (Roma), Italy
 
  The TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for RadioTherapy) proton linear accelerator is under development at ENEA-Frascati. It is composed by a 7 MeV, 425 MHz injector followed by a sequence of 2997.92 MHz accelerating modules. Four 10 MW klystrons will be used to power all high frequency structures up to a beam energy of 150 MeV. The first section, consisting of 4 SCDTL modules (7 to 35 MeV), is operational at low repetition rate (up to 50 Hz). Whereas beam acceleration is effective even without closed loop control, to ensure high beam current stability the resonance frequency variation must be kept for each SDCTL module within few kHz. This is achieved implementing an automatic frequency control (AFC) loop that detects structure detuning caused by thermal drifts and produce an error signal fed to a tuning motor. A prototype of an AFC custom solution, derived from a medical electron linac, has been tested on TOP-IMPLART accelerator. This was originally designed for magnetron frequency tuning with much larger frequency span. Other AFC systems with different components have been evaluated in order to reach the high required resolution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF018  
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TUPAF020 Performance of the CERN Low Energy Ion Ring (LEIR) with Xenon beams injection, MMI, linac, extraction 705
 
  • R. Alemany-Fernández, S.C.P. Albright, O. Andujar, M.E. Angoletta, J. Axensalva, H. Bartosik, G. Baud, N. Biancacci, M. Bozzolan, S. Cettour Cave, K. Cornelis, J. Dalla-Costa, M. Delrieux, A. Dworak, A. Findlay, F. Follin, A. Frassier, M. Gabriel, A. Guerrero, M. Haase, S. Hirlaender, S. Jensen, V. Kain, L.V. Kolbeck, Y. Le Borgne, D. Manglunki, O. Marqversen, S. Massot, D. Moreno Garcia, D.J.P. Nicosia, S. Pasinelli, L. Pereira, D. Perez, A. Rey, J.P. Ridewood, F. Roncarolo, A. Saá Hernández, R. Scrivens, O.G. Sveen, G. Tranquille, E. Veyrunes
    CERN, Geneva, Switzerland
 
  In 2017 the CERN Low Energy Ion Ring demonstrated once more the feasibility of injecting, accumulating, cooling and accelerating a new nuclei, 129Xe39 . The operation of this new ion species started at the beginning of March with the start up of the xenon ion source and the Linac3. Ten weeks later the beam arrived to the Low Energy Ion Ring (LEIR) triggering the start of several weeks of beam commissioning in view of providing the injector complex with Xenon beams for different experiments and a series of machine development experiments in LEIR. Two types of beams were setup, the so called EARLY beam, with a single injection into LEIR from Linac3, and the NOMINAL beam with up to seven injections. 2017 was as well an interesting year for LEIR because several improvements in the control system of the accelerator and in the beam instrumentation were done in view of increasing the machine reliability. This paper summarises the beam commissioning phase and all the improvements carried out during 2017.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF020  
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TUPAF068 Functional Integration of the RFQ in the ESS Systems rfq, cavity, LLRF, vacuum 890
 
  • J.S. Schmidt, E. Bargalló, T. Fay, G. Hulla, B. Lagoguez, R. Montaño, E. Sargsyan, S. Scolari, H. Spoelstra
    ESS, Lund, Sweden
  • A.C. Chauveau, M. Desmons, O. Piquet
    CEA/IRFU, Gif-sur-Yvette, France
  • A.J. Johansson
    Lund University, Lund, Sweden
  • W. Ledda
    Vitrociset s.p.a, Roma, Italy
 
  The 352 MHz Radio Frequency Quadrupole (RFQ) for the European Spallation Source ERIC (ESS) will be delivered during 2018. After delivery, installation and tuning of the cavity, the high power RF conditioning will be performed. At this point all the different systems that are needed to condition and operate the RFQ have to be in place and operational. This paper will give an overview of the system analysis that has been performed for the RFQ. The RFQ requirements for the RF system, including the RF distribution system (RFDS), the Low Level RF (LLRF) and the local RF protection system (RFLPS) will be presented. In addition, the paper covers the system integration of the structure in the ESS control and vacuum systems as well as the outcome of a machine protection analysis.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF068  
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TUPAF090 Measurements of the MYRRHA-RFQ at the IAP Frankfurt rfq, dipole, simulation, resonance 949
 
  • K. Kümpel, D. Koser, S. Lamprecht, N.F. Petry, H. Podlech, A. Schempp, D. Strecker
    IAP, Frankfurt am Main, Germany
  • A. Bechtold
    NTG Neue Technologien GmbH & Co KG, Gelnhausen, Germany
  • C. Zhang
    GSI, Darmstadt, Germany
 
  Funding: Work supported by the EU Framework Programme H2020 662186 (MYRTE)
The MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) Project is a planned accelerator driven system (ADS) which aims to demonstrate the feasibility of large scale transmutation. The first RF structure of the 600 MeV MYRRHA Linac will be a 176.1 MHz 4-Rod RFQ that will accelerate up to 4 mA protons in cw operation from 30 keV up to 1.5 MeV. The voltage along the approximately 4 m long electrodes has been chosen to 44 kV which limits the RF losses to about 25 kW/m. During the design of the structure a new method of dipole compensation has been applied. This paper describes the status of the RFQ and shows the results of the measurements done at IAP Frankfurt such as dipole and flatness measurement, vacuum tests and power tests up to 11 kW.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF090  
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TUPAK010 The Development of a New Low Field Septum Magnet System for Fast Extraction in Main Ring of J-PARC septum, power-supply, operation, feedback 981
 
  • T. Shibata, K. Ishii, H. Matsumoto, T. Sugimoto
    KEK, Ibaraki, Japan
  • K. Fan
    HUST, Wuhan, People's Republic of China
 
  The J-PARC Main Ring (MR) is being upgraded to improve its beam power to the design goal of 750 kW. One important way is to reduce the repetition period from 2.48 s to 1.3 s so that the beam power can be nearly doubled. We need to improve the septum magnets for fast extraction. We are improving the magnets and their power supplies. The present magnets which are conventional type have problem in durability of septum coil by its vibration, and large leakage field at the flange of the beam duct. The new magnets are eddy current type. The eddy current type does not have septum coil, but has a thin plate. We expect that there is no problem in durability, we can construct the thin septum plate, the leakage field can be reduced. The output of the present power supply are pattern current which of flat top is 10 ms width, the new one is short pulse which of one is 10 us. The short pulse consists of 1st and 3rd higher harmonic. We can expect that the flatness and reproducibility of flat top current can be improved. The calorific power can be also reduced. This paper will report the performance of the power supply and its magnetic field with the eddy septum magnet systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK010  
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TUPAK011 Present Status and Future Upgrades of the J-PARC Ring RF Systems proton, cavity, power-supply, operation 984
 
  • M. Yoshii, M. Furusawa, K. Hara, K. Hasegawa, C. Ohmori, Y. Sugiyama
    KEK, Tokai, Ibaraki, Japan
  • M. Nomura, T. Shimada, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
 
  J-PARC is the multipurpose research institutes. 10 years have passed since the user operation started. We have been considering the upgrades for the future and the target beam powers for 3 GeV rapid cycling synchrotron (RCS) and 30GeV Main ring (MR) are 1.5MW and 1.3MW. To achieve a 1.5MW of RCS output beam power, increasing the number of Linac proton particles is necessary. For accelerating such higher beam current, the rf systems in the RCS need to upgrade an accelerating voltage and to take account of heavier beam loading. In case of the MR, increasing the number of proton is not appropriate from the viewpoint of space charge effects. We chose to shorten the MR cycle time. The required RF voltages become almost double. All nine systems have been replaced with the higher accelerating gradient RF systems using a newly developed magnetic alloy material. At present, the proton beam of 470kW is being delivered with a cycle time of 2.48s. Beam powers of MR will plan to aim first at 750KW after replacing the magnet power supplies. But, to realize a 1.3MW beam power, upgrading the RF power sources will be necessary. We present the ring RF system status and their upgrades for the future.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK011  
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TUPAK015 The SARAF-LINAC Project 2018 Status linac, cryomodule, cavity, status 994
 
  • N. Pichoff, D. Chirpaz-Cerbat, R. Cubizolles, J. Dumas, R.D. Duperrier, G. Ferrand, B. Gastineau, P. Gastinel, F. Gougnaud, M. Jacquemet, C. Madec, Th. Plaisant, F. Senée, A. Sutra-Fourcade, D. Uriot
    IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France
  • D. Berkovits, J. Luner, A. Perry, E. Reinfeld, J. Rodnizki
    Soreq NRC, Yavne, Israel
  • M. Di Giacomo
    GANIL, Caen, France
 
  SNRC and CEA collaborate to the upgrade of the SARAF accelerator to 5 mA CW 40 MeV deuteron and proton beams (Phase 2). CEA is in charge of the design, construction and commissioning of the MEBT line and the superconducting linac (SARAF-LINAC Project). The prototypes of the 176 MHz NC rebuncher, SC cavities, RF coupler and SC Solenoid-Package are under construction and their test stands construction or adaptation is in progress at Saclay. Meanwhile, the cryomodules and the global system just passed their Critical Design Reviews. This paper presents the status of the SARAF-LINAC Project at April 2018.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK015  
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TUPAL033 Time-of-Flight, Beam-Energy Measurement of the LANSCE 805-MHz Linac linac, proton, pick-up, DTL 1075
 
  • Y.K. Batygin, F.E. Shelley, H.A. Watkins
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396.
Control of the beam-energy ramp along the length of a proton linear accelerator is required to keep the accelerator tuned according to design. Historically, the values of the field amplitudes and phases of the side-coupled, 805-MHz LANSCE linac modules are maintained using a well-known delta-t tuning procedure*. Time-of-flight measurements of the proton beam energy are now also being used to confirm and improve the overall control of the energy ramp along the linac. The time-of-flight method uses measurements of the difference in RF phases measured as the beam passes installed delta-t pickup loops. A newly developed chassis to control the 3D position of the beam centroid is used. Details of the procedure and results of measurements are presented.
* K.R.Crandall, "The Delta-T Tuneup Procedure for the LAMPF 805-MHz Linac", LANL Report LA-6374-MS, June 1976.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL033  
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TUPAL036 Slow Extraction Techniques at the Marburg Ion-Beam Therapy Centre extraction, synchrotron, simulation, resonance 1084
 
  • C. Krantz, T. Fischer, Th. Haberer, B. Kroeck, U. Scheeler, A. Weber, M. Witt
    MIT, Marburg, Germany
  • R. Cee, F. Faber, E. Feldmeier, M. Galonska, Th. Haberer, A. Peters, S. Scheloske, C. Schömers
    HIT, Heidelberg, Germany
  • F. Faber
    Technische Universität Darmstadt (TU Darmstadt, RMR), Darmstadt, Germany
 
  The Marburg Ion-Beam Therapy Centre offers hadron therapy using proton and carbon beams. The accelerator is based on a 65-m ion synchrotron by Danfysik/Siemens Healthcare. Beam extraction from the synchrotron is driven by a transverse RF knock-out (KO) system featuring Dynamic Intensity Control (DIC) of the spill. DIC allows modulation of the extraction rate by factors up to 30 on millisecond time scales. A fast response of the system to the variable intensity set-point can be obtained by careful adjustment of the RF-KO spectrum relative to the machine tune. Tracking simulations of the extraction phase have been conducted to refine that behaviour. Presently, we investigate how fast machine tune shifts, induced by an air-core quadrupole lens, can be used as a way to further improve the spill quality.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL036  
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TUPAL039 Commissioning of the FRIB RFQ rfq, MMI, cavity, dipole 1090
 
  • H.T. Ren, J.F. Brandon, N.K. Bultman, M.G. Konrad, H. Maniar, D.G. Morris, P. Morrison, G. Pozdeyev, X. Rao, R. Walker, S. Zhao
    FRIB, East Lansing, USA
 
  Funding: This work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 #wei@frib.msu.edu
The radio-frequency quadrupole (RFQ) at the Facility for Rare Isotope Beams (FRIB) is a 4-vane type cavity designed to accelerate heavy ion beams with charge states Q/A between 1/7 and 1/3 from 12 keV/u to 0.5 MeV/u. The RFQ was assembled in the FRIB tunnel in November 2016. Bead-pull measurements and tuning were performed with low RF power. The RFQ has been conditioned to 59 kW in August 2017, which is sufficient to accelerate the Key Performance Parameter (KPP) beams, Argon and Krypton. The RFQ has been successful-ly commissioned with KPP beams in CW regime in Octo-ber 2017. 40Ar9+ and 86Kr17+ beams were accelerated by the FRIB RFQ in the CW regime to the designed energy of 0.5 MeV/u. With the multi-harmonic buncher operation-al, the FRIB RFQ commissioning has been completed with bunched beam in February 2018. The beam trans-mission efficiency through the RFQ was in good agree-ment with PARMTEQ simulation results. The detailed results from the FRIB RFQ tuning, high power condition-ing and beam commissioning will be presented in this paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL039  
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TUPAL054 Experimental Measurements of Resonances near to the ISIS Working Point resonance, experiment, synchrotron, space-charge 1132
 
  • P.T. Griffin-Hicks, B. Jones, B.G. Pine, C.M. Warsop, M. Wright
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  ISIS is the pulsed spallation neutron source located at the Rutherford Appleton Laboratory in the UK. Operation is based on a 50 Hz, 800 MeV proton synchrotron, accelerating up to 3·1013 protons per pulse (ppp), which provides beam to two target stations. ISIS is beam loss limited, so to achieve greater beam intensity and optimal operation, losses must be reduced. Some beam loss may be attributed to resonance lines found in betatron tune space. These could be driven by higher order magnet field components, errors or misalignment. This paper describes work measuring losses against tune space around the ISIS working point. Experiments have been carried out to measure beam loss against tune in the ISIS synchrotron. The experiments were done at low intensity to minimise space charge and intensity effects. Resonance lines that cause beam loss can be clearly identified and provide new information about the machine. The experimental process has been automated in order to decrease experiment duration and to reduce systematic human error. MAD-X models that compare the beam envelope at different points in tune space to the beam pipe aperture are used to distinguish between losses caused by increased envelope size and losses induced by driven resonances.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL054  
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TUZGBD3 Beam Diagnostics for the APS MBA Upgrade feedback, diagnostics, undulator, electron 1204
 
  • N. Sereno, N.D. Arnold, R.W. Blake, A.R. Brill, H. Bui, J. Carwardine, G. Decker, L. Emery, T. Fors, P.S. Kallakuri, R.T. Keane, R.M. Lill, D.R. Paskvan, A.F. Pietryla, H. Shang, X. Sun, S. Veseli, J. Wang, S. Xu, B.X. Yang
    ANL, Argonne, Illinois, USA
 
  The Advanced Photon Source (APS) is currently in the preliminary design phase for a multi-bend acromat (MBA) lattice upgrade. Beam stability is critical where the requirements are driven from the beam size which is expected to approach 4 microns vertically at the insertion device (ID) source points. AC rms beam stability requirements are defined as 10 % the minimum source size at the ID in the band 0.01-1000 Hz. The vertical plane stability goal is the most ambitious requiring a stability of 400 nm at the ID source point. In addition, long term drift defined as motion over a seven day timescale can be no more than 1 micron. In order to achieve these demanding beam stability requirements, a suite of beam diagnostics will be required including rf BPMs, X-ray BPMs, a mechanical motion measurement system, beam size monitors and a real time orbit feedback system. In addition, a tune measurement system, transverse multi-bunch feedback system and current monitors are planned for the upgrade. We report on the beam diagnostics design and APS storage ring R&D results used to inform the design.  
slides icon Slides TUZGBD3 [16.753 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBD3  
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TUPMF080 Progress on Multibunch FEL Performance at FLASH cavity, operation, FEL, accelerating-gradient 1452
 
  • T. Hellert, Ch. Schmidt
    DESY, Hamburg, Germany
 
  At the SASE-FEL user facility FLASH, superconducting TESLA-type cavities are used for acceleration. The high achievable duty cycle allows for operating with long bunch-trains, hence considerably increasing the efficiency of the machine. However, RF induced intra-bunch-train trajectory variations were found to be responsible for significant variations of the SASE intensity within one bunch train. This work presents the latest achievements in improving the multi-bunch FEL performance by reducing the intra-bunch-train variation of RF parameters. Particular attention is given to the static and dynamic detuning of the cavities. It will be shown that the current level of LLRF control is suitable to limit the variation of RF parameters considerably.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF080  
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TUPMF082 FLASHForward: DOOCS Control System for a Beam-Driven Plasma-Wakefield Acceleration Experiment laser, timing, detector, hardware 1460
 
  • S. Karstensen, S. Bohlen, J. Dale, M. Dinter, J.M. Müller, P. Niknejadi, J. Osterhoff, K. Poder, P. Pourmoussavi, V. Rybnikov, L. Schaper, B. Schmidt, J.-P. Schwinkendorf, B. Sheeran, G.E. Tauscher, S. Thiele, S. Wesch, P. Winkler
    DESY, Hamburg, Germany
 
  The FLASHForward project at DESY is an innovative beam-driven plasma-wakefield acceleration experiment integrated in the FLASH facility, aiming to accelerate electron beams to GeV energies over a few centimetres of ionised gas. These accelerated beams are tested for their capability to demonstrate exponential free-electron laser gain; achievable only through rigorous analysis of both the driver and witness beam's phase space. The thematic priority covered in here the control system part of FLASHForward. To be able to control, read out and save data from the diagnostics into DAQ, the DOOCS control system has been integrated into FLASH Forward. Laser beam control, over 70 cameras, ADCs, timing system and motorised stages are combined into the one DOOCS control system as well as vacuum and magnet controls. Micro TCA for Physics (MTCA.4) is the solid basic computing system, supported from high power workstations for camera read-out and normal Linux computers.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF082  
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TUPML045 Segmented Terahertz Driven Device for Electron Acceleration electron, acceleration, laser, linac 1642
 
  • D. Zhang
    DESY, Hamburg, Germany
  • A-L. Calendron, H. Cankaya, M. Fakhari, A. Fallahi, Y. Hua, N.H. Matlis, X. Wu, L.E. Zapata
    CFEL, Hamburg, Germany
  • M. Hemmer, F.X. Kärtner
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • F.X. Kärtner
    MIT, Cambridge, Massachusetts, USA
 
  Funding: ERC Synergy Grant AXSIS (609920), Deutsche Forschungsgemeinschaft (SPP1840 SOLSTICE and CUI EXC1074), and Gordon and Betty Moore foundation (ACHIP GBMF4744)
We present a segmented THz based device (STEAM) capable of performing multiple high-field operations on the 6D-phase-space of ultrashort electron bunches. Using only a few microjoules of single-cycle THz radiation, we have shown record THz-based acceleration of >30 keV of an incoming 55keV electron beam, with a peak acceleration field gradient of around 70 MV/m that is comparable with that from a conventional RF accelerator. It can be scaled up to GV/m gradients that can accelerate electrons into the MeV regime. At the same time, the STEAM device can also manipulate the electrons that show high focusing gradient (2 kT/m), compression of electron bunches down to 100 fs and streaking gradient of 140 µrad/fs, which offers temporal profile characterizations with resolution below 10 fs. The STEAM device can be fabricated with regular mechanical machining tools and supports real-time switching between different modes of operation. It paves the way for the development of THz-based compact electron guns, accelerators, ultrafast electron diffractometers and Free-Electron Lasers.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML045  
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TUPML073 Ion Source and Low Energy Beam Transport Line Final Commissioning Step and Transfer from INFN to ESS MMI, proton, ion-source, vacuum 1712
 
  • L. Celona, A. Amato, G. Calabrese, A.C. Caruso, G. Castro, F. Chines, S. Gammino, O. Leonardi, A. Longhitano, G. Manno, S. Marletta, D. Mascali, A. Maugeri, M. Mazzaglia, A. Miraglia, L. Neri, S. Passarello, A. Seminara, D. Siliato, A. Spartà, G. Torrisi
    INFN/LNS, Catania, Italy
 
  At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) was completed in November 2017. All requirements have been satisfied and certified by the European Spallation Source (ESS). In the last step of the commissioning a complete characterization of the source has been carried out and some results are hereinafter reported. The shipment of the source was done in December 2017, followed by the installation in January while the beam commissioning is foreseen during summer 2018. The paper describes the final commissioning steps at INFN-LNS, the procedure adopted for a safe transfer of the equipment, the transfer of knowledge needed for the operation and the maintenance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML073  
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WEXGBF3 RF System for FRIB Accelerator cavity, LLRF, rfq, linac 1765
 
  • D.G. Morris, J. Brandon, N.K. Bultman, K.D. Davidson, A. Facco, P.E. Gibson, L. Hodges, M.G. Konrad, T.L. Larter, H. Maniar, P. Morrison, P.N. Ostroumov, J.T. Popielarski, G. Pozdeyev, H.T. Ren, T. Russo, K. Schrock, R. Walker, J. Wei, T. Xu, Y. Xu, S. Zhao
    FRIB, East Lansing, USA
  • A. Facco
    INFN/LNL, Legnaro (PD), Italy
 
  The RF system of the FRIB driver accelerator includes solid state amplifiers up to 18 kW operating at frequencies from 80.5 MHz to 322 MHz. Much higher power is required for the normal conducting RFQ, ~100 kW, and it is based on vacuum tubes. This invited talk presents the performance of solid state amplifiers and LLRF in off-line testing and on-line testing of the RFQ amplifier.  
slides icon Slides WEXGBF3 [14.111 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBF3  
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WEPAF030 HEPS High-Level Software Architecture Plan database, software, EPICS, operation 1884
 
  • C.P. Chu, Y.S. Qiao, C.H. Wang
    IHEP, Beijing, People's Republic of China
  • H.H. Lv
    SINAP, Shanghai, People's Republic of China
 
  Funding: Work supported by the Chinese Academy of Science and the HEPS-TF Project.
The High Energy Photon Source (HEPS) is a planned ultra-low emittance synchrotron radiation based light source which requires high precession control systems for both accelerator and beamlines. Such kind of accelerators will require extremely sophisticated high-level control software for both accelerator and beamline operation to achieve not only the demanded precision but also high reliability. This paper outlines the high-level application software architecture design including relational data-bases, software platforms, and advanced controls with machine learning (ML) techniques. Early plan for beam-line control is also reported. For better quality control and easy maintenance, the high-level applications will be built upon matured software platforms. Also, the HEPS High-Level Software team will collaborate with EPICS community for improving the software platforms.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF030  
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WEPAF032 An Alternative Fast Orbit Feedback Design of HEPS feedback, lattice, emittance, closed-orbit 1888
 
  • X.Y. Huang, J.S. Cao, Y.Y. Du, F. Liu, Y.H. Lu, Y.F. Ma, Y.F. Sui, S.J. Wei, Q. Ye, X.E. Zhang, D.C. Zhu
    IHEP, Beijing, People's Republic of China
 
  The High Energy Photon Source (HEPS) is a fourth generation light source in China and will be built in this year. The emittance of HEPS storage ring is approaching diffraction limit and the circumstance of the ring is about 1.3 kilometres. To stabilize the electron beam, fast orbit feedback (FOFB) system is prerequisite. In this paper, the requirements on the HEPS beam stability are discussed and an alternative FOFB design based on DBPM are introduced with algorithm and architecture.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF032  
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WEPAF044 Automatic Tuning of PETRA, its Injector Complex, and Prospects of Autonomous Operation of PETRA IV operation, optics, software, synchrotron 1912
 
  • I.V. Agapov, H. Ehrlichmann, J. Keil, G.K. Sahoo, R. Wanzenberg
    DESY, Hamburg, Germany
  • Y.-C. Chae
    ANL, Argonne, Illinois, USA
 
  We present the progress in tuning automation of the PETRA injection complex. The OCELOT optimizer has been ported to the PETRA control system and proof-of-principle tests of transmission efficiency optimization done. We further argue that the next steps in tuning and automation are impossible without rethinking the architecture of the high level contol system. A possible approach to the new system is then sketched.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF044  
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WEPAF052 High QL and High Gradient CW Operation of Tesla SCRF 9-Cell Cavity cavity, feedback, operation, FEL 1937
 
  • K.P. Przygoda, V. Ayvazyan, L. Butkowski, M. Hierholzer, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
    DESY, Hamburg, Germany
 
  In the paper we would like to present Tesla SCRF 9-Cell cavity operated at CW regime with extremely high QL at gradients above 23 MV/m. The design hardware and firmware components as well as developed high level software procedures allows automatic procedure of cavity trip from low to high gradient operation. The microphonics as well as a pendoromotive effects are sensed, identify and applied for cavity detuning correction. The RF and piezo feedbacks performance are demonstrated and preliminary results are briefly discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF052  
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WEPAF053 Status and Commissioning of the European XFEL Beam Loss Monitor System FEL, electron, high-voltage, hardware 1940
 
  • T. Wamsat, T. Lensch, P.A. Smirnov
    DESY, Hamburg, Germany
 
  The European XFEL MTCA based Beam Loss Monitor System (BLM) is composed of about 450 monitors, which are part of the Machine Protection System (MPS). The BLMs detect losses of the electron beam, in order to protect accelerator components from damage and excessive activation, in particular the undulators, since they are made of permanent magnets. Also each cold accelerating module is equipped with a BLM to measure the sudden onset of field emission (dark current) in cavities. In addition some BLMs are used as detectors for wire- scanners. Experience from the already running BLM system in FLASH2 which is based on the same technology, led to a fast implementation of the system in the XFEL. Further firmware and server developments related to alarm generation and handling are ongoing. The BLM systems structure, the current status and the different possibilities to trigger alarms which stop the electron beam will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF053  
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WEPAF054 Online Multi Objective Optimisation at Diamond Light Source injection, sextupole, lattice, EPICS 1944
 
  • M. Apollonio, R. Bartolini, R.T. Fielder, I.P.S. Martin
    DLS, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  • G. Henderson
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • J. Rogers
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  At Diamond Light Source we have developed an Optimization Package currently used online to improve the performance of the machine, usually measured in terms of lifetime, injection efficiency or beam disturbance at injection. The tool is flexible in that control variables in order to optimise objectives (or their functions) can be easily specified by means of EPICS process variables (PV), making it suitable for virtually any sort of optimization. At present three different algorithms can be used to perform optimizations in a multi-objective fashion: Multi-Objective Genetic Algorithm (MOGA), Particle Swarm Optimizer (MOPSO) and Simulated Annealing (MOSA). We present a series of tests aimed at characterizing the algorithm as well as improving the performance of the machine itself.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF054  
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WEPAF062 Machine Learning Methods for Optics Measurements and Corrections at LHC optics, network, quadrupole, data-analysis 1967
 
  • E. Fol, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, R. Tomás
    CERN, Geneva, Switzerland
 
  The application of machine learning methods and concepts of artificial intelligence can be found in various industry and scientific branches. In Accelerator Physics the machine learning approach has not found a wide application yet. This paper is devoted to evaluation of machine learning methods aiming to improve the optics measurements and corrections at LHC. The main subjects of the study are devoted to recognition and analysis of faulty beam position monitors and prediction of quadrupole errors using clustering algorithms, decision trees and artificial neural networks. The results presented in this paper clearly show the suitability of machine learning methods for the optics control at LHC and the potential for further investigation on appropriate approaches.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF062  
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WEPAF064 Dependable Implementation of the Beam Interlock Mechanism in CERN Power Converter Controllers operation, software, experiment, interface 1975
 
  • M. Di Cosmo, Q. King, R. Murillo-Garcia, D. Nisbet, B. Todd
    CERN, Geneva, Switzerland
 
  At CERN a Beam Interlock System (BIS) protects accelerators from accidental and uncontrolled release of beam energy, avoiding machine downtime. Throughout the accelerator complex numerous critical subsystems, including power converters, interact with the BIS indicating their readiness for operation with beam. Power converters play a vital role in establishing operational conditions, and an unmitigated power converter malfunction could lead to damage to the machine. For example a bending magnet converter set at an incorrect current would result in an incorrect field strength, and beam passing through this may impact and damage the machine. A fast and dependable Beam Interlock Mechanism is required between power converters and BIS, verifying that voltage and current levels are within tolerances. This paper describes the design and realisation of the Beam Interlock Mechanism, based on CERN's Function Generator Controller (FGC), the central processing unit power converter control. Particular emphasis is placed on the system architecture required to assure the integrity of the power converter parameters, and the protection of the CERN accelerator complex.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF064  
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WEPAF073 Ultra-Wideband Transverse Intra-Bunch Feedback: Beginning Development of a Next Generation 8GSa/s System FPGA, feedback, interface, diagnostics 2001
 
  • J.E. Dusatko, J.D. Fox
    SLAC, Menlo Park, California, USA
 
  Funding: US Department of Energy DE-AC02-76SF00515, US LHC Accelerator Research Program, CERN LHC Injector Upgrade Project and the US-Japan Cooperative Program in High Energy Physics.
Building on the success of our 4GSa/s wideband trans-verse feedback system, we have begun development of a next generation ultra-wideband feedback processor which doubles the effective sampling rate to 8GSa/s. This higher sampling rate and proportional increase in analog band-width enable enhanced flexibility and diagnostics for accelerator transverse feedback such as control of higher-order modes, more detailed diagnostic information, im-proved SNR and two channel processing of total charge and orbit signals, with multiple pickups. Though targeted for ongoing transverse intra-bunch instability studies at the CERN SPS with a 1.7ns bunch length, the increased performance paves the way for instability control and diagnostics applications for other machines such as the HL-LHC and FCC. This paper discusses the beginning development process including an evaluation of the high-est speed AtoD and DtoA data converter devices at time of this writing and selection of the devices used in our design. It then describes the architecture of the full 8GSa/s prototype feedback processor and the design approach, which involves using both custom and commercial components enabling rapid and flexible development.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF073  
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WEPAF077 Performance Evaluation of Linac4 During the Reliability Run linac, operation, MMI, proton 2016
 
  • O. Rey Orozko, A. Apollonio, S.S. Erhard, G. Guidoboni, B. Mikulec, J.A. Uythoven
    CERN, Geneva, Switzerland
 
  Linac4 will replace Linac2 as the first element in the CERN proton injector chain from 2020 onwards, following the second LHC long shutdown (LS2). With more than three times higher energy and number of compo-nents than Linac2, beam availability is one of the main challenges of Linac4. Intended as a smooth transition from commissioning to operation, a Linac4 Reliability Run was started in July 2017 and is foreseen to last until mid-May 2018. The goal is to achieve the target availability of 95 %. This implies consolidated routine operation and identification of recurring problems. This paper introduces the schedule and operational aspects of the Linac4 Reliability Run, including the developed tools and methods for availability tracking. The paper also summarizes the lessons learned during the first period of the Linac4 Reliability Run with respect to fault tracking and provides an in-depth analysis of the failure modes and observed availability.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF077  
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WEPAF079 A Smart Framework for the Availability and Reliability Assessment and Management of Accelerators Technical Facilities operation, framework, GUI, experiment 2024
 
  • L. Serio, A. Castellano, U. Gentile
    CERN, Geneva, Switzerland
  • F. Antonello, P. Baraldi, E. Zio
    Politecnico di Milano, Milan, Italy
 
  CERN operates and maintains a large and complex technical infrastructure serving the accelerator complex and experiments detectors. A performance assessment and enhancement framework based on data mining, artificial intelligence and machine-learning algorithms is under development with the objective of structuring, collecting and analyzing systems and equipment operation and failure data, to guide the identification and implementation of adequate corrective, preventive and consolidation interventions. The framework is designed to collect and structure the data, identify and analyze the associated driving events. It develops dynamically functional dependencies and logic trees, descriptive and predictive models to support operation and maintenance activities to improve the reliability and availability of the installations. To validate the performance of the framework and quality of the algorithms several case studies are being carried out. We report on the design, implementation and on the preliminary results inferred on historical and live stream data from CERN's technical infrastructure. Proposal for the full deployment and expected long-term capabilities will also be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF079  
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WEPAF081 An Enhanced Quench Detection System for Main Quadrupole Magnets in the Large Hadron Collider quadrupole, monitoring, power-supply, radiation 2032
 
  • J. Spasic, D.O. Calcoen, R. Denz, V. Froidbise, S. Georgakakis, T. Podzorny, A.P. Siemko, J. Steckert
    CERN, Geneva, Switzerland
 
  To further improve the performance and reliability of the quench detection system (QDS) for main quadrupole magnets in the Large Hadron Collider (LHC), there is a planned upgrade of the system during the long shutdown period of the LHC in 2019-2020. While improving the already existing functionalities of quench detection for quadrupole magnets and field-bus data acquisition, the enhanced QDS will incorporate new functionalities to strengthen and improve the system operation and maintenance. The new functionalities comprise quench heater supervision, interlock loop monitoring, power cycling possibility for the whole QDS and its data acquisition part, monitoring and synchronization of trigger signals, and monitoring of power supplies. In addition, the system will have two redundant power supply feeds. Given that the enhanced QDS units will replace the existing QDS units in the LHC tunnel, the units will be exposed to elevated levels of ionizing radiation. Therefore, it is necessary to design a radiation tolerant detection system. In this work, an overview of the design solution for such enhanced QDS is presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF081  
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WEPAF090 CS-Studio Operator Training at ReA3 interface, status, EPICS, power-supply 2061
 
  • T. Summers, D.B. Crisp
    NSCL, East Lansing, Michigan, USA
  • A.C.C. Villari
    FRIB, East Lansing, Michigan, USA
 
  Funding: This material is based upon work supported by the National Science Foundation under Grant No. PHY-1565546
In the past year, Control System Studio (CS-Studio) has become the predominant graphical user interface tool at ReA3, the 3 MeV/u rare isotope beam Reaccelerator at Michigan State University's National Superconducting Cyclotron Laboratory. CS-Studio is a set of control system interface tools that include operator interfaces, history plots, an alarm handler, save/restore, scanning, and more. Becoming an effective user of these tools takes considerable time and training. This contribution will describe the challenges and strategies for training operators on the general use of the CS-Studio tools. It will describe the use of a simulated user interface environment for training operators at any time without affecting the operating facility.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF090  
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WEPAG004 Automating Orbit Correction in the Main Injector 8 GeV Line dipole, booster, data-acquisition, operation 2070
 
  • K.J. Hazelwood, I. Kourbanis, G.E. Krafczyk, M.-J. Yang
    Fermilab, Batavia, Illinois, USA
 
  The Main Injector 8 GeV line (MI8 line) transports beam from Fermilab's Booster accelerator to either the Booster Neutrino experiments (BNB), the Recycler or the Main Injector. Often the orbit of the beam through the MI8 line differs depending on the beam destination. The beam is collimated in the MI8 line, so increasing intensities and repetition rates make controlling orbits through the collimators a necessity. The current method of regulating the MI8 line orbit with DC corrector settings is insufficient. A system named MITUNE is being developed to sample and categorize all beams through the MI8 line and automatically calculate and apply proper dipole corrector ramps to maintain desired orbits for pulses to any destination.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAG004  
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WEPAG005 Synchrotron Radiation Beam Diagnostics for the Integrable Optics Test Accelerator electron, optics, synchrotron, proton 2073
 
  • N. Kuklev, Y.K. Kim
    University of Chicago, Chicago, Illinois, USA
  • A.L. Romanov
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by the U.S. National Science Foundation under Award PHY-1535639. Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy.
The Integrable Optics Test Accelerator (IOTA) is a research electron and proton storage ring currently being commissioned at Fermilab's Accelerator Science and Technology (FAST) facility. An extensive beam physics research program is planned, including tests of novel techniques for improving beam intensity, stability, and emittance. A key part of IOTA beam diagnostics suite are synchrotron light beam monitors, mounted onto each dipole. In this paper, we present the hardware and software design of this system. Mechanical layout and actuator control electronics are described. High throughput image acquisition and analysis architecture is outlined, and its preliminary performance is explored. Integration of the system within accelerator control network and possible user applications, such as camera auto-focusing, are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAG005  
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WEPAK003 Effect of Model Errors on the Closed Orbit Correction at the SIS18 Synchrotron of GSI quadrupole, synchrotron, closed-orbit, focusing 2080
 
  • S.H. Mirza, P. Forck, H. Klingbeil, R. Singh
    GSI, Darmstadt, Germany
  • H. Klingbeil
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  Funding: Deutscher Akademischer Austauschdienst under contract No. 91605207
A fast closed orbit feedback system (bandwidth in the order of 1 kHz) is under development at the GSI SIS18 synchrotron for the orbit correction from injection to extraction including the acceleration ramp. The static process model, represented as the orbit response matrix (ORM), is subjected to the systematic optics changes during ramp e.g. beta function and phase advance variations at the locations of BPMs and steerers. In addition to these systematic variations, model mismatches may arise from dipole and quadrupole magnet errors, space charge dependent tune shift as well as BPM and steerer calibration errors. In this contribution, the effects of these model errors on the closed orbit correction are investigated which is necessary for the robust stability analysis of the feedback controller. For the robustness tests, the traditional SVD-based matrix pseudo-inversion is compared to a Fourier-based analysis. The results are achieved by detailed simulations in MADX.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK003  
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WEPAK012 Developing Kalman Filter Based Detuning Control with a Digital SRF CW Cavity Simulator cavity, SRF, FPGA, LLRF 2114
 
  • A. Ushakov, P. Echevarria, A. Neumann
    HZB, Berlin, Germany
 
  Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of the Helmholtz Association
Continuous wave operated superconducting cavities experiencing small net beam loading and thus operate potentially at narrow bandwidth require precise detuning control to reach the high stability requirements for RF fields within facilities as FEL or ERL based photon sources. Especially microphonics compensation down to sub-hertz detuning regime besides improving stability reduces the risk of rise of Lorentz force detuning driven ponderomotive instabilities. Usually the complex and second order nature of the mechanical to RF detuning transfer functions of cavity and cavity-tuner system require for more advanced control schemes. In this paper we will show the application of a Kalman filter based detuning estimator algorithm first introduced during IPAC2017 [1] to the SRF cavity simulator developed at Helmholtz Zentrum Berlin [2]. Results using the algorithm in observer mode to detuning compensation attempts in closed loop mode are presented.
* A. Ushakov, P. Echevarria, A. Neumann, Proc. of IPAC 2017, Copenhagen, Denmark
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK012  
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WEPAK013 SRF Cavity Simulator for LLRF Algorithms Debugging cavity, SRF, LLRF, FPGA 2118
 
  • P. Echevarria, J. Knobloch, A. Neumann, A. Ushakov
    HZB, Berlin, Germany
  • E. Aldekoa, J. Jugo
    University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
 
  Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
The availability of niobium superconducting cavities, ei-ther due to a lack of a real cavity or due to the time needed for the experiment set up (vacuum, cryogenics, cabling, etc.), is limited, and thus it can block or delay the develop-ment of new algorithms such as low level RF control. Hardware-in-the-loop simulations, where an actual cavity is replaced by an electronics system, can help to solve this issue. In this paper we present a Cavity Simulator imple-mented in a National Instruments PXI equipped with an FPGA module. This module operates with one intermedi-ate frequency input which is IQ-demodulated and fed to the electrical cavity's model, where the transmitted and re-flected voltages are calculated and IQ-modulated to gener-ate two intermediate frequency outputs. Some more ad-vanced features such as mechanical vibration modes driven by Lorentz-force detuning or external microphonics have also been implemented. This Cavity Simulator is planned to be connected to an mTCA chassis to close the loop with a LLRF control system.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK013  
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WEPAK014 A New Pulse Magnet Control System in the KEK Electron Positron LINAC power-supply, EPICS, timing, software 2121
 
  • Y. Enomoto, K. Furukawa, T. Natsui, M. Satoh
    KEK, Ibaraki, Japan
  • H.S. Saotome
    Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
 
  In 2017, sixty-four pules magnets were installed in the KEK e+/e LINAC for simultaneous injection to four different rings. Since each ring requires different injection energy, magnetic field in the LINAC has to be changed shot by shot (every 20 ms) according to the destination of the beam. To realize such operation, a PXI express based new control system was installed. Each unit, which consists of an event receiver board, a DAC board, and a ADC board, can set and monitor output current up to 8 pulsed power supply in 16 bit resolution. The timing and control system are integrated in that of the LINAC by using Micro-Research Finland's PXI event receiver board. In terms of software, Windows 8.1 and LabVIEW 2016 were mainly adopted to control the hardware. EPICS channel access (CA) protocol was used to communicate with operator's interface panels. In addition to real-time monitoring by EPICS CA and logging by CSS archiver every 10 s, data are logged every shot (every 20 ms) in the text file together with timestamp, shot ID and destination. At present, thirteen units are stably in operation to control 64 magnets. Further installation of the system is planned in 2018.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK014  
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WEPAK015 Beam Gate Control System for SuperKEKB injection, operation, hardware, software 2124
 
  • H. Kaji, Y. Ohnishi, S. Sasaki, M. Satoh, H. Sugimura
    KEK, Ibaraki, Japan
  • Y. Iitsuka
    EJIT, Hitachi, Ibaraki, Japan
  • T. Kudou
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
 
  The electron beam pulses of injector linac for the SuperKEKB collider are enabled and disabled by Beam Gate control system. This system controls the delivery of triggers to the electron guns at the injector. Also, the septum and kicker magnets for injection point of main ring are controlled with this Beam Gate to avoid unnecessary operation and to prolong their lifetime. The Beam Gate synchronizes the enabling and disabling operations of these hardware even though they are about 1km distant. Besides, from the phase-2 operation, the kicker and septum magnets for newly constructed damping ring becomes controlled apparatus of this system. We develop the new Beam Gate control system with the Event Timing System network*. The new system improves the unsatisfied performance of Beam Gate in the phase-1 operation and realizes the complicated control for phase-2. The advantages of new system are: the control signal is delivered via Event nettork, so that we do not need to cable new network. The enabling and disabling operations for distant hardware are surely synchronized by the Event Timing System.
* H. Kaji et al., "Construction and Commissioning Event Timing System at SuperKEKB", Proceedings of IPAC14, Dresden, Germany (2014).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK015  
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WEPAK016 RF Monitor System for SuperKEKB Injector Linac linac, FPGA, data-acquisition, EPICS 2128
 
  • H. Katagiri, M. Akemoto, D.A. Arakawa, T. Matsumoto, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
 
  A new radio frequency (RF) monitor system for the SuperKEKB project has been developed at the KEK in-jector linac. The RF monitor unit, which consists of an analog I/Q demodulator, ADC/DAC board, and FPGA board achieved 50-Hz data acquisition and beam mode identification. On the RF monitor, the amplitude and phase measurement precision has achieved 0.1% rms and 0.1° rms, respectively. Sixty RF monitor units have been installed in the linac. The present status of the RF monitor system will be re-ported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK016  
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WEPAK017 Low-level RF System for the SuperKEKB Injector LINAC linac, injection, booster, positron 2131
 
  • T. Matsumoto, M. Akemoto, D.A. Arakawa, H. Katagiri, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
  • M. Akemoto, T. Miura, F. Qiu
    Sokendai, Ibaraki, Japan
 
  The low-level RF (LLRF) system of the KEK injector linac has been upgraded for the SuperKEKB. As a major change, a low-emittance and high-current RF gun was installed to satisfy 40-times higher luminosity at the SuperKEKB. In order to balance the stable RF gun operation and the electron/positron beam acceleration, the phase shifter is developed and the configuration of main drive system in the LLRF system is modified. The present status and future plan of the LLRF system upgraded for the SuperKEKB will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK017  
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WEPAK018 LLRF Control Unit for SuperKEKB Injector Linac LLRF, linac, klystron, timing 2134
 
  • T. Miura, M. Akemoto, D.A. Arakawa, H. Katagiri, T. Matsumoto, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
  • N. Liu
    Sokendai, Ibaraki, Japan
 
  The low-level RF (LLRF) control unit based on the digital system has been developed for a stable and high precision pulse modulation for the SuperKEKB. The RF pulse is changed at a 50-Hz repetition rate for the top-up injection to four different rings by the event system. The LLRF control unit has not only the pulse modulator, but also other functions: VSWR meter, RF monitor, event receiver (EVR), and pulse-shortening detection.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK018  
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WEPAL001 LLRF Control and Master Oscillator System for Damping Ring at SuperKEKB cavity, LLRF, injection, linac 2137
 
  • T. Kobayashi, K. Akai, A. Kabe, K. Nakanishi, M. Nishiwaki, J.-I. Odagiri
    KEK, Ibaraki, Japan
  • H. Deguchi, K. Hayashi, J. Mizuno
    Mitsubishi Electric TOKKI Systems, Amagasaki, Hyogo, Japan
  • K. Hirosawa
    Sokendai, Ibaraki, Japan
 
  For SuperKEKB, new low level RF (LLRF) control systems has ben developed and they worked successfully in the first beam commissioning (Phase-1) of SuperKEKB, which was accomplished in 2016. Damping ring (DR) was newly constructed for positron beam injection, in order to make significantly emittance smaller for SuperKEKB. The beam commissioning of DR will be conducted in JFY2017 for the Phase-2 commissioning. Phase-2 is scheduled in the last quater of JFY2017. DR has an RF station, and two cavities (or three cavities in future) are driven by a klystron. New LLRF control system for DR (DR-LLRF) was also developed and installed. RF frequency of DR operation is common with the main storage rings (MR) of SuperKEKB. The good performance of DR-LLRF was demonstrated in test operation, and RF conditioning of the pair of two cavities was successfully completed in June 2017. This paper reports the detail of the performance results of DR-LLRF controls, and also the other some relevant issues in LLRF controls for DR, including the master oscillator system (synchronization with the injection linac), are introduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL001  
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WEPAL002 Improvement of Personnel and Machine Protection System in Superkekb Injector Linac linac, operation, PLC, gun 2140
 
  • I. Satake, H. Honma, A. Shirakawa, N. Toge
    KEK, Ibaraki, Japan
 
  Since summer of 2010, the radiation control area for the KEK electron positron injector linac had been split at the around 3 GeV point by a concrete wall into upstream and downstream parts with independent beam sources. This was so as to allow operation of the downstream part for beam injection into photon factory rings while construction and development of new electron guns proceed in the upstream part. In summer of 2017, this arrangement was revised and the entire injector linac was reconsolidated into a single radiation control area. This was in conjunction with the introduction of the 1.1 GeV positron damping ring for Phase-II operation of SuperKEKB and successful development of new electron RF guns in the far upstream part of the linac. Along with this reconsolidation, the personnel and machine protection system was modified and improved. Interlock signal lines for the damping ring and RF guns were added. The operation panel of the main console was modified accordingly. In addition, the screen displays of the interlock status were updated. In this paper we report on the renewed system of KEK injector linac in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL002  
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WEPAL003 Baseband Simulation Model of the Vector RF Voltage Control System for the J-PARC RCS feedback, simulation, cavity, software 2144
 
  • F. Tamura, M. Nomura, T. Shimada, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • M. Furusawa, K. Hara, K. Hasegawa, C. Ohmori, Y. Sugiyama, M. Yoshii
    KEK, Tokai, Ibaraki, Japan
 
  Vector rf voltage feedback control for the wideband magnetic alloy cavity of the J-PARC RCS is considered to be employed to compensate the heavy beam loading caused by high intensity proton beams. A prototype system of multiharmonic rf vector voltage control has been developed and is under testing. To characterize the system performance, full rf simulations could be performed by software like Simulink, while the software is proprietary and expensive. Also, it requires much computing power and time. We performed the simplified baseband simulations of the system in z-domain by using free software, Scilab and Python control library. It seems to be beneficial for searching the parameters that the baseband simulation can be performed quickly. In this presentation, we present the setup and results of the simulations. The simulations well reproduce the open and closed loop responses of the prototype system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL003  
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WEPAL008 Low-level RF System for The Chinese ADS Front-end Demo Linac LLRF, cavity, linac, interface 2159
 
  • J.Y. Ma, Z. Gao, G. Huang, L.P. Sun
    IMP/CAS, Lanzhou, People's Republic of China
 
  The Chinese ADS Front-end Demo Linac (FDL) is constructed to demonstrate the technology of superconducting linac with high proton beam loading of CW 10mA. The low-level RF (LLRF) control system for the ADS FDL is developed by IMP, and the cooperation with TRIUMF. In the normal conducting (NC) section, the normal RF feedback control loop is used. In order to stable the superconducting (SC) cavity with loaded high RF power, the self excited loop with phase locked mode was used on the SC linac. This paper introduces the LLRF control system for buncher, SC linac, and the structures of hardware and the functions of software of these LLRF systems. The operating status of the LLRF systems is also reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL008  
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WEPAL015 Improvement of Motor Control System in J-PARC Linac and RCS operation, hardware, radiation, PLC 2180
 
  • H. Takahashi, A. Miura, Y. Sawabe, M. Yoshimoto
    JAEA/J-PARC, Tokai-mura, Japan
  • M. Kawase, T. Suzuki
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
 
  In J-PARC, at the Linac wire scanner, the RCS collimator, and etc., a motor control system by VME is constructed as a drive system of them. Since the malfunction of operation occurred in the control system of the RCS collimator drive system in 2016, we decided to improve the motor control system. As a cause of malfunction, it is considered that aging of control equipment is one of them as J-PARC has been operated for more than 10 years. However, the defect did not occur in the reproduction test. Therefore, it can be considered that a malfunction occurred in the VME control system due to abnormality of the semiconductor element due to radiation ray. Then, in the improved motor control system, PLC with FA* specification with high reliability was adopted as the control device. Also, in case of unexpected event that a malfunction occurred in the PLC, the emergency stop mechanism was developed to stop the drive system by the signal of the limit switch, and a system incorporating it was constructed. In this paper, we show the inference of cause of the malfunction and details the improved motor control system with high safety.
* Factory Automation
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL015  
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WEPAL016 Tensile Fracture Test of Metallic Wire of Beam Profile Monitors linac, electron, cavity, beam-loading 2183
 
  • A. Miura, Y. Kawane, K. Moriya
    JAEA/J-PARC, Tokai-mura, Japan
  • S. Fukuoka
    Nihon Koshuha Co. Ltd, Yokohama, Japan
  • K. Futatsukawa, T. Miyao
    KEK, Ibaraki, Japan
 
  In order to mitigate the beam loss during a beam transportation in a high-brilliant accelerator facilities, wire-based profile monitors are used to measure by both transverse and longitudinal beam profiles using wire-scanner monitors (WSMs) and bunch-shape monitors (BSMs) for the tuning of quadrupole magnets and bunching cavities. Signals are come from the direct interaction between a metallic wire and beam. We have used the tungsten wire as a high melting-point material by estimation of heat loading during the impact of beam particles. In addition, a spring is applied for the relaxing a sag under wire's own weight. A tensile fracture test is conducted by supplying an electrical current as a simulated beam-heat loading. As the results, we obtained the relation between the thermal limit to break down and tension loading of tungsten wire.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL016  
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WEPAL017 Adaptive Feedforward Control Design Based on Simulink for the J-PARC LINAC LLRF System LLRF, cavity, linac, simulation 2187
 
  • S. Li
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Z. Fang, Y. Fukui, K. Futatsukawa, F. Qiu
    KEK, Ibaraki, Japan
  • S. Mizobata, Y. Sato, S. Shinozaki
    JAEA/J-PARC, Tokai-mura, Japan
 
  In j-parc linac, for dealing with high beam loading effect, an adaptive feedforward control method which based on iterative learning control was put forward. At the same time, in order to verify its effectiveness before it is officially put into use, an llrf system simulation model was built in simulink, matlab. In this paper, the architecture of llrf system simulation model will be introduced. The result of iterative learning control (ILC) is summarized.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL017  
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WEPAL024 High Precision Beam Parameter Stabilization for P2 at MESA experiment, cavity, electron, resonance 2209
 
  • R.F.K. Kempf, J. Diefenbach
    IKP, Mainz, Germany
  • K. Aulenbacher
    HIM, Mainz, Germany
 
  Funding: Cluster of Excellence PRISMA (EXC 1098/2014) German Research Foundation DFG (GRK 2128)
The experiment P2 will measure the weak mixing angle with an all-time high precision via electron-proton scattering. The measured physics asymmetry and its uncertainty has to be corrected by the apparatus' asymmetry, which is generated by helicity correlated fluctuations of the beam parameters position, angle, intensity and energy. This Poster will describe how the high precision of 0.1 ppb of the parity violating asymmetry can be provided by the high precision measurements of the parameters position, angle and intensity.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL024  
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WEPAL029 FLUTE Diagnostics Integration diagnostics, cavity, interface, linac 2227
 
  • M. Yan, A. Bernhard, E. Bründermann, S. Funkner, A. Malygin, S. Marsching, W. Mexner, A. Mochihashi, A.-S. Müller, M.J. Nasse, G. Niehues, R. Ruprecht, T. Schmelzer, M. Schuh, N.J. Smale, P. Wesolowski, S. Wüstling
    KIT, Karlsruhe, Germany
  • I. Križnar
    Cosylab, Ljubljana, Slovenia
 
  FLUTE (Ferninfrarot Linac- Und Test-Experiment) will be a new compact versatile linear accelerator at KIT. Its primary goal is to serve as a platform for a variety of accelerator studies as well as to generate strong ultra-short THz pulses for photon science. The machine consists of an RF gun, a traveling wave linac and a D-shaped bunch compressor chicane with corresponding diagnostics sections. In this contribution, we report on the latest developments of the diagnostics components. An overview of the readout and control system integration will be given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL029  
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WEPAL030 Deep Learning Based Predictive Control for RFT-30 Cyclotron cyclotron, network, simulation, operation 2230
 
  • Y.B. Kong, M.G. Hur, E.J. Lee, J.H. Park, H.S. Song, S.D. Yang
    KAERI, Jeongeup-si, Republic of Korea
 
  Successful construction of the control system is an important problem in the accelerator. The RFT-30 cyclotron is 30 MeV cyclotron for radioisotope production and fundamental researches. To operate the RFT-30 cyclotron for beam irradiation, the human operators should carefully manipulate the control parameters. If the control does not function properly, it becomes difficult to handle the cyclotron and cannot perform the accurate operations for the control. In this work, we propose a deep learning based model predictive control approach for the RFT-30 cyclotron. The proposed approach is composed of two steps: system identification and a control design. In the system identification procedure, the proposed approach constructs the predictive model of the accelerator using the deep learning approach. In the control design stage, the controller finds the optimal control inputs by solving the optimization problem. To analyze the performance of the proposed approach, we applied the approach into the RFT-30 cyclotron.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL030  
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WEPAL031 RF Interlock Implementation Using Digital LLRF System for 100 MeV Proton Linac at KOMAC pick-up, cavity, LLRF, proton 2233
 
  • H.S. Jeong, Y.-S. Cho, H.S. Kim, J.H. Kim, S.G. Kim, H.-J. Kwon, Y.G. Song
    Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
 
  Funding: This work has been supported through KOMAC (Korea Multi-purpose Accelerator Complex) operation fund of KAERI by MSIT (Ministry of Science and ICT)
KOMAC (Korea Multi-purpose Accelerator Complex) already has operated 100 MeV proton linear accelerator with high availability since 2013. This accelerator is composed of Ion source, LEBT, RFQ and DTL systems to transport proton particles to the target. Total 9 klystrons with 1.6 MWpeak are used to provide controlled RF power to the accelerator cavities with 350 MHz of operating frequency. These klystrons are driven by LLRF systems that the LLRF systems should control the RF and protect the amplifiers and cavities from the abnormal RF. In this article, the RF interlock using cavity pickup signal introduced. When the cavity pickup amplitude breaks away from the adjustable upper or lower limit window, the digital LLRF system interrupts the LLRF output. These implementations were conducted by upgrading the FPGA (Field Programmable Gate Array) logics of the existing digital LLRF system.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL031  
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WEPAL039 LCLS-II Gun/Buncher LLRF System Design gun, LLRF, cavity, SRF 2258
 
  • G. Huang, K.S. Campbell, L.R. Doolittle, J.A. Jones, Q. Qiang, C. Serrano
    LBNL, Berkeley, California, USA
  • S. Babel, A.L. Benwell, M. Boyes, G.W. Brown, D. Cha, J.H. De Long, J.A. Diaz Cruz, B. Hong, A. McCollough, A. Ratti, C.H. Rivetta, D. Rogind, F. Zhou
    SLAC, Menlo Park, California, USA
  • R. Bachimanchi, C. Hovater, D.J. Seidman
    JLab, Newport News, Virginia, USA
  • B.E. Chase, E. Cullerton, J. Einstein-Curtis, D.W. Klepec
    Fermilab, Batavia, Illinois, USA
  • J.A. Diaz Cruz
    CSU, Fort Collins, Colorado, USA
 
  Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract n. DE-AC02-05CH11231.
For a free electron laser, the stability of injector is critical to the final electron beam parameters, e.g., beam energy, beam arrival time, and eventually it determines the photon quality. The LCLS-II project's injector contains a VHF copper cavity as the gun and a two-cell L-band copper cavity as its buncher. The cavity designs are inherited from the APEX design, but requires more field stability than demonstrated in APEX operation. The gun LLRF system design uses a connectorized RF front end and low noise digitizer, together with the same general purpose FPGA carrier board used in the LCLS-II SRF LLRF system. The buncher LLRF system directly adopts the SRF LLRF chassis design, but programs the controller to run the normal conducting cavities. In this paper, we describe the gun/buncher LLRF system design, including the hardware design, the firmware design and bench test.
 
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WEPAL040 High Precision Synchronization Development for HiRES, the Ultrafast Electron Diffraction Beamline at LBNL laser, electron, LLRF, gun 2262
 
  • Y. Yang, K.M. Baptiste, M. Betz, L.R. Doolittle, Q. Du, D. Filippetto, G. Huang, F. Ji
    LBNL, Berkeley, California, USA
 
  Precise synchronization between the laser and electron is critical for the pump-probe experiments in the HiRES Ultrafast Electron Diffraction facility. We are upgrading the LLRF and laser control system, which ultimately aims at a synchronization below 50 fs RMS between the pump laser pulse and electron probe at the sample plane. Such target poses tight requirements on the RF field stability both in amplitude and phase, and on the synchronization between the RF field and the laser repetition rate. We are presently developing a new LLRF system that has the potential to decrease the overall noise, reaching the required stability of tens of ppm on RF amplitude and phase. For the laser control side, we are replacing the long coaxial cables with fibers for both control signal transmission and laser signal reception. The control transmission side has been implemented, and the timing jitter has been reduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL040  
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WEPAL041 FPGA Based Optical Phase Control for Coherent Laser Pulse Stacking cavity, experiment, FPGA, laser 2265
 
  • Y. Yang, L.R. Doolittle, Q. Du, G. Huang, W. Leemans, R.B. Wilcox, T. Zhou
    LBNL, Berkeley, California, USA
  • A. Galvanauskas
    University of Michigan, Ann Arbor, Michigan, USA
 
  Coherent temporal pulse stacking combines the energy from a train of pulses into one pulse through a series of optical cavities. To stabilize the output energy, the cavity roundtrip phases must be precisely locked to particular values. Leveraging the LLRF expertise we have for conventional accelerators, a FPGA-based control system has been developed for optical cavity phase control. A phase measurement method, ''Modulated Impulse Response'', has been developed and implemented on FPGA. An experiment demonstrated that it can measure and lock the optical phases of four stacking cavities, leading to combination of 25 pulses into one pulse with 1.5 % RMS stability over 30 hours.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL041  
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WEPAL043 Distributed Control Architecture for an Integrated Accelerator and Experimental System FPGA, hardware, software, real-time 2268
 
  • D.J. Gibson, R.A. Marsh, B. Rusnak
    LLNL, Livermore, California, USA
 
  Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
A neutron imaging demonstration system is under construction at LLNL, integrating 4 MeV and 7 MeV deuteron accelerators with gas-based neutron production target the associated supply and return systems. This requires integrating a wide variety of control points from different rooms and floors of the Livermore accelerator facility at a single operator station. The control system adopted by the commercial vendor of the accelerators relies on the National Instruments cRIO platform, so that hardware system has been extended across all the beamline and experimental components. Here we present the unified, class-based framework that has been developed and implemented to connect the operator station through the deployed Real Time processors and FPGA interfaces to the hardware on the floor. Connection between the deployed processors and the operator workstations is via a standard TCP/IP network and relies on a publish/subscribe model for data distribution. This measurement and control framework has been designed to be extensible as additional control points are added, and to enable comprehensive, controllable logging of shot-correlated data at up to 300 Hz.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL043  
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WEPAL046 A New Digital Feedback and Feedforward Controller for Cavity Field Control of the LANSCE Accelerator cavity, feedback, LLRF, FPGA 2277
 
  • S. Kwon, L.J. Castellano, D.J. Knapp, J.T.M. Lyles, M.S. Prokop, A. Scheinker, P.A. Torrez
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work Supported by DOE
A new digital low-level RF system was designed and has been deployed on the drift-tube-linac section of the Los Alamos Neutron Science Center(LANSCE) proton accelerator. This new system is part of a modernization of the existing analog cavity-field controls that were originally developed and put into service forty-five years ago. For stabilization of the cavity field amplitude and phase during beam loading, a proportional-integral feedback controller, a static beam feedforward controller, and an iterative learning controller working in parallel have been implemented. In this paper, the controller architecture is described, and the performances of the three controllers when beam is being actively accelerated is presented.
 
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WEPAL048 Control Command Strategy for the ThomX Accelerator HOM, TANGO, GUI, network 2284
 
  • H. Guler, N. ElKamchi, P. Gauron, H. Monard
    LAL, Orsay, France
 
  ThomX is an accelerator project designed to create a compact X Compton Backscattering Source for medical and cultural heritage applications. Control-Command (CC) system is a central part for the commissionning. ThomX CC is designed with TANGO SCADA system. This framework allows to control several devices from several places with the same SCADA System. TANGO Device Servers are software programs allowing to control devices and to implement data processing and presentation layers. For commissionning, experts need to access values of each device in a convenient way to allow them to modify parameters and check effect of a configuration on hardware. CC is a key part for this stage. Several GUI have been designed and gathered into several panels in collaboration with each expert group to gather their needs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL048  
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WEPAL051 Mirascope Residual-Gas Luminescent Beam Profile Monitors electron, diagnostics, proton, operation 2291
 
  • V.G. Dudnikov, R.J. Abrams, M.A. Cummings
    Muons, Inc, Illinois, USA
 
  Muons, Inc. proposes to develop a Residual-Gas Beam Profile Monitor for Transfer Lines with pulse-to-pulse precision of better than 0.1 mm in position and size that will operate over a wide range of proton beam intensities including those needed for multi-MW beams of future facilities. Traditional solid-based beam intercepting instrumentation produces unallowable levels of radiation at high powers. Our alternative approach is to use a low mass residual-gas profile monitor, where ionization electrons are collected along extended magnetic field lines and the gas composi-tion and pressure in the beam pipe are locally controlled to minimize unwanted radiation and to improve resolu-tion. Beam Induced Fluorescence profile monitor with micrascope light collection is proposed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL051  
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WEPAL053 Dynamic Signal Analysis Based on FPGA for NSRRC DLLRF cavity, FPGA, LLRF, feedback 2295
 
  • F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  As DLLRF control system designs for SRF cavities have greatly matured and the FPGA technology has im-proved as well, it is possible now to think about incorporating dynamic signal analysis (DSA). Implementation of a DSA in the FPGA is desired to study the frequency response of the open/closed loop gain in a SRF system. Open loop gain is useful to observe the stability of a SRF system while closed loop gain can be applied to investi-gate the operational bandwidth of the system feedback and also to configure the performance of a PID controller. The DSA function was confirmed by analyzing the frequency response of a digital filter and the results of the analysis will be compared with MATLAB simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL053  
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WEPAL054 Digital Low Level Radio Frequency System for the Booster Ring of the Taiwan Photon Source LLRF, cavity, operation, booster 2298
 
  • Z.K. Liu, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  The purpose of a Low-Level Radio Frequency (LLRF) system is to control the accelerating cavity field amplitude and phase. For the Taiwan Photon Source (TPS) at NSRRC, the currently operating LLRF systems are based on analog technology. To have better RF field stability, precise con-trol and high noise reduction, a digital LLRF control sys-tems based on Field Programmable Gate Arrays (FPGA) was developed. We replaced the analog LLRF system with the digital version for the TPS booster ring at the beginning of 2018, and we will replace those in the storage rings in the future. Test results and operational performance of the TPS booster DLLRF system are reported here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL054  
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WEPAL059 Observation and Suppression of Beam Orbit Drift Due to Path Length Changes and Thermal Effect in TPS site, feedback, operation, electron 2313
 
  • P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.-C. Kuo
    NSRRC, Hsinchu, Taiwan
 
  Tidal effect, ambient temperature fluctuation and other effects of the TPS site can cause the path length changes of the electron beam in the TPS storage ring. Off-energy orbit drifts from the path length change, if not varying the RF frequency, cannot be properly corrected by the horizontal correctors and this causes the fast orbit feedback system over its normal working range. RF frequency adjustment loop is therefore applied to compensate for the circumference change based on the accumulating corrector strengths of the fast orbit feedback system. Implementation and operational experiences will be discussed in the report.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL059  
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WEPAL079 Control of Intra-Bunch Vertical Motion in the SPS with GHz Bandwidth Feedback feedback, damping, injection, kicker 2365
 
  • J.D. Fox, J.E. Dusatko, C.H. Rivetta, O. Turgut
    SLAC, Menlo Park, California, USA
  • H. Bartosik, E.R. Bjørsvik, W. Höfle, G. Kotzian, K.S.B. Li, E. Métral, B. Salvant, U. Wehrle
    CERN, Geneva, Switzerland
  • S. De Santis
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by the U.S. Department of Energy DE-AC02-76SF00515, US LHC Accelerator Research program, CERN LHC Injector Upgrade Project and the US-Japan Cooperative Program in High Energy Physics.
A GHz bandwidth vertical beam feedback system has been in development at the CERN SPS to explore control of unstable beam motion in single bunch and bunch train configurations. We present measurements and recent studies of stable and unstable motion for intensities up to 2x1011 p/bunch. The system has been operated at 3.2GS/s with 16 samples across a 5 ns RF bucket (4.2 ns 3 σ bunch at injection). Experimental results confirm damping of intra-bunch instabilities in Q20, Q22 and Q26 optics configurations. Instabilities with growth times of 200 turns are well-controlled from injection, consistent with the achievable gains for the 2 installed stripline kickers with 1 kW broadband total power. Studies of the damping achieved with the diagonal FIR controllers and existing system noise floors are highlighted to evaluate benefits of MIMO feedback controllers. The work is motivated by anticipated intensity increases from the LIU and HL-LHC upgrade programs, and has included the development of a new 1 GHz bandwidth slotline kicker structure and associated amplifier system
 
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WEPMF001 Upgrade of the ALBA Magnetic Laboratory for Measuring LIPAc HEBT Quadrupoles and Dipole quadrupole, hardware, software, dipole 2369
 
  • J. Campmany, F. Becheri, L.G.O. Garcia-Orta, J. Marcos, V. Massana, R. Petrocelli
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • B. Brañas, J. Castellanos
    CIEMAT, Madrid, Spain
 
  Along 2017 ALBA magnetic measurements facility has measured LIPAc HEBT quadrupoles and dipole designed by CIEMAT and built by ELYTT company. ALBA magnetic measurements laboratory has been improved through an upgrade program of its measurement benches to complete their measurements. One of the main aims of the upgrade has been to standardize both the hardware and software and therefore ensure an easy maintenance. Especially relevant has been the upgrade of the flipping coil bench, in which the DC motors and the obsolete controller have been replaced by step-motors and ICEPAP controller. Also, software has been migrated to Tango package. Hardware and software of Hall probe bench has been upgraded as well, using the last DeltaTau motion controller. Tango has been upgraded too, using Devian 8 as operative system. Next step will be the upgrade of the rotating coil hardware and software using also step-motor and ICEPAP controller. In parallel, new shafts have been build and tested, with specific designs to improve the sensitivity and minimize the noise to signal ratio. In this contribution we detail the upgrades and the results of performance tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF001  
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WEPMF002 Operational Experience with IOTs at Alba Synchrotron cavity, cathode, electron, operation 2372
 
  • J.R. Ocampo, B. Bravo, R. Fos, F. Pérez, A. Salom, P. Solans
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • S. Bethuys, A. Beunas, M. Grezaud, P. Reynaud
    TED, Velizy-Villacoublay, France
  • M. Boyle, J. Cipolla, W.F. Coyle, H. Schult
    L-3, Williamsport, Pennsylvania, USA
 
  ALBA is a 3 GeV Synchrotron light source in operation since 2012. The RF systems are based in Inductive Output Tube (IOT) transmitters. A total of 13 80 kW IOT amplifiers are used to power the Storage Ring and Booster cavities at 500 MHz. The transmitters were initially configured to operate the TH-793-1 and TH-794 IOT from THALES Electron devices. On 2015, the amplifiers have been adapted to operate also the TH-795 from THALES and the L4444-C from L3 Communications. In this paper, a brief overview of the differences between these IOT models will be presented, as well as operation results for each type of IOT from the point of view of performance, reliability and durability.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF002  
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WEPMF005 Design and Testing of a 12 kW, 352 MHz Solid State rf System at the Advanced Photon Source cavity, operation, GUI, simulation 2378
 
  • D. Horan, D.J. Bromberek, A. Goel, T.J. Madden, A. Nassiri, G.J. Waldschmidt
    ANL, Argonne, Illinois, USA
 
  A 12 kW, 352 MHz rf power amplifier system was designed and constructed at the Advanced Photon Source as a research and development test bed for eventual development of a 200 kW cw rf system capable of supporting accelerator beam operation. The system utilizes six 2 kW laterally diffused metal oxide field effect transistor (MOSFET) rf amplifiers, an output cavity combiner terminated with a WR2300 waveguide output flange, and a monitoring system based on programmable logic controller technology. The combining cavity has a total capacity of 108 two-kilowatt inputs to support eventual operation up to 216kW maximum output power. Design details and operational performance of the 12 kW system will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF005  
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WEPMF008 Preliminary Designs and Test Results of Bipolar Power Supplies for APS Upgrade Storage Ring power-supply, hardware, operation, storage-ring 2381
 
  • J. Wang, I.A. Abid, R.T. Keane, G.S. Sprau
    ANL, Argonne, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The upgrade (APS-U) of the APS storage ring requires more than 1200 bipolar power supplies. Based on the performance requirement, the power supplies can be divided into two categories: fast bipolar power supplies for fast correctors and slow bipolar power supplies for trim coils and slow correctors. The common requirement of the power supplies is a bipolar output current up to ±15 A. The main difference is that the fast corrector power supplies require a small-signal bandwidth of 10 kHz. A prototype DC/DC power converter utilizing a MOSFET H-bridge circuit with a 500 kHz PWM was successfully developed through the R&D program, achieving the required bandwidth with less than 3-dB attenuation for a signal 0.5% of ±15 A. After the successful R&D program, the preliminary designs were performed to further improve the performance and to finalize the schematics, the PCB layouts, and the power supply constructions. The two types of the power supplies share the majority of the designs and features, with minor differences for the different bandwidth requirement. This paper presents the preliminary design, the key power supply functions and features, and the test results.
 
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WEPMF038 Microphonics Suppression in the CBETA Linac Cryomodules cavity, linac, cryomodule, SRF 2447
 
  • N. Banerjee, J. Dobbins, F. Furuta, G.H. Hoffstaetter, R.P.K. Kaplan, M. Liepe, P. Quigley, E.N. Smith, V. Veshcherevich
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: This work was performed through the support of New York State Energy Research and Development Agency. The linac cryomodules were constructed with funding from the National Science Foundation.
The Cornell-BNL ERL Test Accelerator (CBETA) is a new multi-turn energy recovery linac currently under construction at Cornell University. It uses two superconducting linacs, both of which are susceptible to microphonics detuning. The high-current injector accelerates electrons to 6 MeV and the main linac accelerates and decelerates electrons by 36 MeV. In this paper, we discuss various measures taken to reduce vibrations caused by instabilities and flow transients in the cryogenic system of the main linac cryomodule. We further describe the use of a Least Mean Square algorithm in establishing a stable Active Microphonics Compensation system for operation of the main linac cavities.
 
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WEPMF043 Frequency Tuner Development at Cornell for the RAON Half Wave Resonators cavity, cryogenics, cryomodule, operation 2461
 
  • M. Ge, F. Furuta, T. Gruber, S.W. Hartman, M. Liepe, J.T. Maniscalco, T.I. O'Connell, P.J. Pamel, J. Sears, V. Veshcherevich
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • B.H. Choi, J. Joo, J.W. Kim, W.K. Kim, J. Lee, I. Shin
    IBS, Daejeon, Republic of Korea
 
  The superconducting half-wave-resonators for the RAON project require a slow frequency tuner that can provide at least 80 kHz tuning range. Cornell University has designed, prototyped, and tested a tuner for these half-wave-resonators. In this paper, we present the tuner design, prototype fabrication, test insert preparation, long-term testing and tuner performance test results at cryogenic temperature. The performance of the tuner is analyzed in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF043  
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WEPMF054 Design and Status of the MicroTCA.4 Based LLRF System for TARLA LLRF, cavity, hardware, operation 2490
 
  • Gumus, C. Gumus, M. Hierholzer, K.P. Przygoda, H. Schlarb, Ch. Schmidt
    DESY, Hamburg, Germany
  • A.A. Aksoy, A. Aydin
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
 
  The Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is constructing a 40 MeV Free Electron Laser with continuous wave (CW) RF operation. In order to control and monitor the four superconducting (SC) TESLA type cavities as well as the two normal conducting (NC) buncher cavities, a MicroTCA.4 based LLRF system is foreseen. This highly modular system is further used to control the mechanical tuning of the SC cavities by control of piezo actuators and mechanical motor tuners. This paper focuses on giving brief overview on hardware and software components of LLRF control of TARLA, as well as updates on the ongoing integration tests at DESY.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF054  
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WEPMF073 Adaptation of the Cryogenic System Capacity for the LHC Dynamic Heat Load - Operational Experience cryogenics, operation, electron, HOM 2541
 
  • K. Brodzinski, B. Bradu, S.D. Claudet, D. Delikaris, L.P. Delprat, G. Ferlin
    CERN, Geneva, Switzerland
 
  During second LHC physics operation period (Run2), between 2015 and 2018, the accelerator operation modes and beam parameters have been adapted thus allowing significantly improved integrated luminosity production. Increased energy, intensity and adapted beam operation schemes with 25 ns of inter-bunches spacing have an essential influence on the dynamic heat load generation with direct impact on the cryogenic cooling system. In order to cope with significantly higher than expected beam induced thermal load, the cryogenic system was tuned and optimized to adapt the required refrigeration capacity to the beam operational requirements. The most challenging part of tuning was focused on the dynamic heat load compensation on the beam screens circuits. The paper will provide the overview on the main differences between the theoretical heat load values considered for initial design and the on-line measurements performed on cryogenic LHC sectors. Finally, the paper will summarize the methodology and tools implemented in the cryogenic process control system allowing the highly efficient on-line adaptation of the refrigeration power with respect to the beam induced heat load distribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF073  
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WEPMF075 Performance Measurements and Analysis of Jitter Like Events for the PS Injection Kicker System kicker, operation, injection, simulation 2549
 
  • A. Ferrero Colomo, J.C.C.M. Borburgh, L. Ducimetière, L.M.C. Feliciano, V. Forte, M.A. Fraser, T. Kramer, L. Sermeus
    CERN, Geneva, Switzerland
 
  In the framework of the LIU project, several modifications have been made to the CERN PS injection kicker system during the winter stop 2016-2017 (EYETS). Current waveform and beam-based measurements were carried out in 2017 to validate the implemented design changes by observing the magnetic field impact on the beam. During these long-term measurements, increased values for the rise and fall times were observed when compared to single shot observations of the current waveform. An unknown source of jitter-like pre-firing in the main switch has been identified, creating an additional challenge to meet the already tight system rise and fall time specifications. This paper briefly describes the efforts made to fine tune the pulse generator after the EYETS, summarises the optimised configuration and analyses the observed jitter events. A new triggering system design is briefly outlined to address the issue.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF075  
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WEPMF078 Assembly of the DQW Crab Cavity Cryomodule for SPS Test cavity, cryomodule, vacuum, alignment 2561
 
  • M. Garlaschè, K. Artoos, R. Calaga, O. Capatina, T. Capelli, N. El Kbiri, D. Lombard, P.F. Marcillac, P. Minginette, M. Narduzzi, L.R.A. Renaglia, J. Roch, J.S. Swieszek
    CERN, Geneva, Switzerland
  • A. Krawczyk, B. Prochal
    IFJ-PAN, Kraków, Poland
 
  RF Crab Cavities are an essential part of the High Luminosity Upgrade of the LHC accelerating complex. Two concepts of such superconducting systems are being developed: the Double Quarter Wave (DQW) and the RF Dipole (RFD). A prototype cryomodule - hosting two DQW cavities - has been fabricated and assembled for validation tests to be carried out in the Super Proton Synchrotron (SPS) at CERN. An overview of the main cryomodule components is presented, together with the system features and main fabrication requirements. The preparatory measures for cryomodule assembly, the execution and lessons learned are also discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF078  
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WEPMK010 LCLS-II Cryomodules Production at Fermilab cryomodule, cavity, vacuum, FEL 2652
 
  • T.T. Arkan, J.N. Blowers, C.M. Ginsburg, C.J. Grimm, J.A. Kaluzny, A. Lunin, Y.O. Orlov, K.S. Premo, R.P. Stanek, G. Wu
    Fermilab, Batavia, Illinois, USA
 
  Funding: DOE
LCLS-II is a planned upgrade project for the linear coherent light source (LCLS) at SLAC. The LCLS-II linac will consist of thirty-five 1.3 GHz and two 3.9 GHz superconducting RF continuous wave (CW) cryomodules that Fermilab and Jefferson Lab are currently producing in collaboration with SLAC. The LCLS-II 1.3 GHz cryomodule design is based on the European XFEL pulsed-mode cryomodule design with modifications needed for CW operation. Two prototype cryomodules had been assembled and tested. After prototype cryomodule tests, both laboratories have increased cryomodule production rate to meet the challenging LCLS-II project installation schedule requirements of approximately one cryomodule per month per laboratory. Fermilab is at half point for the production, meaning that 6 cryomodules are fully assembled and tested. This paper presents Fermilab Cryomodule Assembly Facility (CAF) infrastructure for the LCLS-II cryomodules assembly, production experience at the half point emphasizing the challenges and mitigations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMK010  
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WEPML001 Passive Microphonics Mitigation during LCLS-II Cryomodule Testing at Fermilab cryomodule, cavity, cryogenics, resonance 2668
 
  • J.P. Holzbauer, B.E. Chase, J. Einstein-Curtis, B.J. Hansen, E.R. Harms, J.A. Kaluzny, A.L. Klebaner, M.W. McGee, Y.O. Orlov, T.J. Peterson, Y.M. Pischalnikov, W. Schappert, R.P. Stanek, J. Theilacker, M.J. White, G. Wu
    Fermilab, Batavia, Illinois, USA
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The LCLS-II project calls for cryomodule production and testing at both Fermilab and JLab. Due to low beam loading and high cavity quality factor, the designed peak detuning specification is 10 Hz. Initial testing showed peak detuning up to 150 Hz with a complex and varying time-structure, showing both fast (1-2 second) and slow (1-2 hour) drifts in amplitude and spectrum. Extensive warm and cold testing showed Thermoacoustic Oscillations in the cryogenic valves were the primary source of the microphonics. This was mitigated by valve wipers and valve re-plumbing, resulting in a greatly improved cavity detuning environment. Additional modifications were made to the cavity mechanical supports and Fermilab test stand to improve detuning performance. These modifications and testing results will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML001  
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WEPML007 Active Microphonics Compensation for LCLS-II cavity, resonance, LLRF, cryomodule 2687
 
  • J.P. Holzbauer, B.E. Chase, J. Einstein-Curtis, Y.M. Pischalnikov, W. Schappert
    Fermilab, Batavia, Illinois, USA
  • L.R. Doolittle, C. Serrano
    LBNL, Berkeley, California, USA
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
Testing of early LCLS-II cryomodules showed microphonics-induced detuning levels well above specification. As part of a risk-mitigation effort, a collaboration was formed between SLAC, LBNL, and Fermilab to develop and implement active microphonics compensation into the LCLS-II LLRF system. Compensation was first demonstrated using a Fermilab FPGA-based development system compensating on single cavities, then with the LCLS-II LLRF system on single and multiple cavities simultaneously. The primary technique used for this effort is a bank of narrowband filter set using the piezo-to-detuning transfer function. Compensation automation, optimization, and stability studies were done. Details of the techniques used, firmware/software implementation, and results of these studies will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML007  
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WEPML011 Garnet Ring Measurements for the Fermilab Booster 2nd Harmonic Cavity cavity, booster, solenoid, simulation 2700
 
  • R.L. Madrak, J.E. Dey, K.L. Duel, J. Kuharik, A.V. Makarov, W. Pellico, J. Reid, G.V. Romanov, M. Slabaugh, D. Sun, C.-Y. Tan, I. Terechkine
    Fermilab, Batavia, Illinois, USA
 
  A perpendicularly biased tuneable 2nd harmonic cavity is being constructed for use in the Fermilab Booster. The cavity's tuner uses National Magnetics AL800 garnet as the tuning media. For quality control, the magnetic properties of the material and the uniformity of the properties within the tuner must be assessed. We describe two tests which are performed on the rings and on their corresponding witness samples.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML011  
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WEPML015 Preparation and Qualification of Jacketed SSR1 Cavities for String Assembly at Fermilab cavity, vacuum, cryomodule, multipactoring 2714
 
  • D. Passarelli, P. Berrutti, S.K. Chandrasekaran, J.P. Ozelis, M. Parise, L. Ristori, A.M. Rowe, A.I. Sukhanov
    Fermilab, Batavia, Illinois, USA
 
  The qualification of dressed 325 MHz Single Spoke Resonators type 1 (SSR1) to meet technical requirements is an important milestone in the development of the SSR1 cryomodule for the PIP-II Project at Fermilab. This paper reports the procedures and lessons learned in processing and preparing these cavities for horizontal cold testing prior to integration into a cavity string assembly.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML015  
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WEPML029 Vacuum System of the HESR at FAIR, Status of Tests, Layout and Manufacturing vacuum, dipole, kicker, injection 2748
 
  • F.M. Esser, N.B. Bongers, J. Böker, P. Chaumet, R. Gebel, R. Greven, S. Hamzic, H. Jagdfeld, F. Klehr, B. Laatsch, G. Langenberg, D. Marschall, A. Mauel, G. Natour, D. Prasuhn, L. Reifferscheidt, M. Schmitt, L. Semke, R. Tölle
    FZJ, Jülich, Germany
 
  The Research Center Jülich is leading a consortium being responsible for the design and manufacturing of the High-Energy Storage Ring (HESR) which is part of the FAIR project in Darmstadt, Germany. The HESR is designed for antiprotons within a momentum range of 1.5-15 GeV/c but can also be used for heavy ion experiments. Therefore the vacuum quality is expected to be 10-11 mbar or better which is a great challenge on the overall vacuum layout as well as on the surface quality of the chambers and beam tubes. Whereas all bent dipole chambers are installed, the manufacturing of the pumping bodies with integrated RF meshes as well as several diagnostic chambers are in the focus of investigation. To validate the intended pumping concept of both the bake-out arc sections and the non-bakable straight sections, final tests at the operational test benches are planned. In parallel, the purchasing of valves and first pumps will be prepared. The actual layout of the HESR vacuum system and its components will be presented as well as the progress of manufacturing of several vacuum chambers. The latest experimental test results will be presented also.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML029  
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WEPML031 The New Broadband Accelerating System for the SIS18 Upgrade at GSI cavity, operation, impedance, resonance 2755
 
  • P. Hülsmann, R. Balß, H. Klingbeil, U. Laier, K.-P. Ningel, C. Thielmann, B. Zipfel
    GSI, Darmstadt, Germany
 
  In this contribution, a new SIS18 rf accelerating system is presented whose cavities are based on magnetic alloy materials. The rf system works at harmonic number h=2 (f=0,43- to 2,8 MHz) and provides the necessary accelerating voltage (up to 50kVp) for SIS18 injector operation for FAIR with high intensity heavy ion beams in a fast operation mode with up to three cycles per second. The paper focusses on the cavity part and its cooling issues as well as the broadband characteristics. Due the lossy magnetic alloy ring core filling, which consists of high permeability Finemet FT3M ring cores (HITACHI), the cavities show a broadband behaviour and thus no cavity tuning during the acceleration ramp is necessary. To keep the bandwidth of the cavities as broad as possible they are cooled by a special mineral oil with low permittivity. Also the beam impedance and the power consumption of the rf system are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML031  
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WEPML032 The FAIR-SIS100 Bunch Compressor RF Station cavity, power-supply, coupling, electronics 2759
 
  • H.G. König, R. Balß, P. Hülsmann, H. Klingbeil, P.J. Spiller
    GSI, Darmstadt, Germany
  • R. Gesche, J.H. Scherer
    Aurion Anlagentechnik GmbH, Seligenstadt, Germany
  • A. Morato, C. Morri, G.T. Taddia
    OCEM, Valsamoggia, Italy
 
  In the frame of the Facility for Antiproton and Ion Research (FAIR) 9 bunch compressor RF stations were ordered for the first stage of realization of the SIS100 synchrotron. For RF gymnastics referred to as bunch rotation, one RF station has to provide a sudden rise in gap voltage of up to 40 kVp within less than 30 µs. The system is designed for a maximum RF burst of 3 ms per second. The RF frequency will be pre-selectable between 310 kHz and 560 kHz at a harmonic number of h=2 with respect to the beam. Compressed bunches with a peak current > 150 A and a width < 50 ns are the goal. For this purpose, a 1.218 m long cavity was designed using iron-based magnetic alloy cores. Variable vacuum capacitors are attached for tuning. The cavity is driven by a cross-coupled push-pull tetrode amplifier. This scheme minimizes the influence of the tetrode's DC current at the working point to the cores. The energy for the pulsed system is stored in a relatively small capacitor bank which will be charged semi-continuously and a voltage-stabilizing device is added. Cavity and power amplifier were realized by AURION Anlagentechnik GmbH ' the power supply unit is designed and built by OCEM Power Electronics.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML032  
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WEPML033 The FAIR-SIS100 Accelerating RF Station cavity, feedback, operation, power-supply 2762
 
  • H.G. König, R. Balß, H. Klingbeil, U. Laier, D.E.M. Lens, P.J. Spiller
    GSI, Darmstadt, Germany
  • G. Blokesch, F. Wieschenberg
    Ampegon PPT GmbH, Dortmund, Germany
  • K. Dunkel, M. Eisengruber, J.H. Hottenbacher
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
  • C. Hiltbrunner
    Ampegon AG, Turgi, Switzerland
 
  For the Facility for Antiproton and Ion Research (FAIR) 14 ferrite loaded accelerating RF stations are planned for the first stage of realization of the SIS100 synchrotron. Each RF station has to provide a total peak gap voltage of up to 20 kVp in CW operation - tuneable in the range of 1.1 MHz up to 3.2 MHz to allow ion beam acceleration and beam gymnastics at different harmonic numbers and energy levels in the new facility. Each RF station consists of a tuneable ferrite cavity, a single ended tetrode amplifier and a dedicated power supply and control unit (PSU) ' including two bias current supplies for cavity- and control-grid(G1)-circuit-tuning. The ferrite cavity is based on the SIS18 cavity concept but has to provide a 1.25 times higher gap voltage of 20 kVp over a total length of 3 meters. The realization is done by a consortium consisting of RI Research Instruments GmbH as consortium leader and manufacturer of the cavity, Ampegon PPT GmbH (for the tetrode amplifier) and Ampegon AG (for the power supply unit). In this contribution, the system design is discussed, and commissioning results are presented. All main parameters are achieved with the RF station described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML033  
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WEPML034 Design and Commissioning of the RF System of the Collector Ring at FAIR power-supply, cavity, MMI, operation 2765
 
  • U. Laier, R. Balß, A. Dolinskyy, P. Hülsmann, H. Klingbeil, T. Winnefeld
    GSI, Darmstadt, Germany
  • G. Blokesch, F. Wieschenberg
    Ampegon PPT GmbH, Dortmund, Germany
  • K. Dunkel, M. Eisengruber, J.H. Hottenbacher
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
  • C. Morri, M.P. Pretelli, G.T. Taddia
    OCEM, Valsamoggia, Italy
 
  The Collector Ring (CR), a storage ring intended to perform efficient cooling of secondary beams, is under construction at GSI in the scope of the FAIR project. The RF system of the CR has to provide a frequency range from 1.1 to 1.5 MHz and pulsed gap voltages of up to 200 kVp (0.2 to 1 Hz, max. 10-3 duty cycle) and up to 10 kVp in CW operation. Five identical RF stations will be built. Each RF station consists of an inductively loaded cavity, a tetrode based power amplifier, a semiconductor driver amplifier, a switch mode power supply and two digital feedback loops. The main components of the RF station are designed, built and commissioned in close collaboration between GSI and three companies: RI Research Instruments GmbH, Ampegon PPT GmbH and OCEM Energy Technology SRL. In 2016, the first of five RF stations has been integrated at GSI. In 2017 the system was successfully commissioned to demonstrate that all envisaged parameters have been achieved. This contribution will present the requirements imposed the system, the principal design of the overall system as well as of its key components, and the results of the commissioning of the first RF station.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML034  
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WEPML035 Superconducting Dipoles for SIS100 dipole, operation, synchrotron, superconducting-magnet 2768
 
  • C. Roux, P. Aguar Bartolome, A. Bleile, E.S. Fischer, G. Golluccio, F. Kaether, J. Ketter, J.P. Meier, A. Mierau, C. Omet, P.J. Spiller, K. Sugita, P.B. Szwangruber, A. Warth, H.G. Weiss
    GSI, Darmstadt, Germany
 
  The international facility for antiproton and ion research (FAIR) is currently being developed in Darmstadt, Germany, for fundamental research in various fields of modern physics. Its main accelerator, the SIS100 heavy ion synchrotron, utilizes fast-cycling superconducting magnets operated at cryogenic temperatures. An intense measurement program of first of series (FoS) module revealed excellent behaviour with respect to, e.g., quench performance and AC losses. With an optimized fabrication technique, the geometrical accuracy was improved to be sufficient to provide a highly homogeneous field. Consequently, the series production of 110 dipoles was released. First significant results on the reproducibility and the variation of physical properties along the series production gained at the test facility of GSI are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML035  
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WEPML051 Improvement of the Chopper System for rf Deflector at the J-PARC Linac timing, cavity, linac, operation 2816
 
  • K. Futatsukawa, Z. Fang, Y. Fukui
    KEK, Ibaraki, Japan
  • Y. Sato
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
  • S. Shinozaki
    JAEA/J-PARC, Tokai-mura, Japan
 
  In the J-PARC linac, the RF deflector has been operated to kick the wasted beam and to shape the intermediate-pulse like the comb structure. Then about 50% of the beam current is removed by leading the scraper and the rest beam current is injected to the downstream synchrotron ring RCS. The fast rising time and falling time, the cavity with low loading Q value in the chopper system are required to decrease the incomplete kicked beam. However, there was the ringing of the RF field on the chopper cavity, and it influenced the beam rising time. The chopper controllers, which has the fast RF -switch to make the particular RF according to the intermediate-pulses, were improved for the RF falling time by outputting short pulses with inverting phase. The beam study for the new system was successfully done. In this paper, I would like to introduce this system and to show the results of the beam study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML051  
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WEPML064 Design of the Trim Coil for the Superconducting Cyclotron Extraction extraction, cyclotron, resonance, flattop 2840
 
  • L.G. Zhang, K. Fan, S. Hu, Z.Y. Mei, Z.J. Zeng
    HUST, Wuhan, People's Republic of China
 
  A proton therapy system is being developed at Huazhong university of science and technology (HUST). A 250 MeV superconducting cyclotron with an average magnetic filed of 3.1 T in the extraction region is selected to reduce the machine size, which creates difficulties for beam extraction because of the small turn separation of the beam orbits in the extraction region. To obtain high extraction efficiency, a carefully controlled magnetic perturbation is introduced to excite resonance when beam passes through the νr =1 resonance. The first-order perturbation in the magnetic field is generated by trim coils within confined regions. The profile of the trim coil and the resultant perturbation fields are optimized iteratively with orbit tracking. Simulation shows that sufficient turn separation can be obtained with the proper setting of trim coils.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML064  
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THXGBD1 The Upgrade of the Advanced Photon Source lattice, feedback, cavity, simulation 2872
 
  • M. Borland, M. Abliz, N.D. Arnold, T.G. Berenc, J.M. Byrd, J.R. Calvey, J.A. Carter, J. Carwardine, H. Cease, Z.A. Conway, G. Decker, J.C. Dooling, L. Emery, J.D. Fuerst, K.C. Harkay, A.K. Jain, M.S. Jaski, P.S. Kallakuri, M.P. Kelly, S.H. Kim, R.M. Lill, R.R. Lindberg, J. Liu, Z. Liu, J. Nudell, C.A. Preissner, V. Sajaev, N. Sereno, X. Sun, Y.P. Sun, S. Veseli, J. Wang, U. Wienands, A. Xiao, C. Yao
    ANL, Argonne, Illinois, USA
  • A. Blednykh
    BNL, Upton, Long Island, New York, USA
 
  After decades of successful operation as a 7-GeV synchrotron radiation source, the Advanced Photon Source is pursing a major upgrade that involves replacement of the storage ring with an ultra-low emittance multi-bend achromat design. Using a seven-bend hybrid multi-bend achromat with reverse bending magnets gives a natural emittance of 42 pm operated at 6 GeV. The x-ray brightness is predicted to increase by more than two orders of magnitude. Challenges are many, but appear manageable based on thorough simulation and in light of the experience gained from world-wide operation of 3\text{rd}-generation light sources. The upgraded ring will operate in swap-out mode, which has allowed pushing the performance beyond the limits imposed by conventional operation.  
slides icon Slides THXGBD1 [14.689 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THXGBD1  
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THYGBE1 Applying Artificial Intelligence to Accelerators FEL, feedback, electron, network 2925
 
  • A. Scheinker, R.W. Garnett, D. Rees
    LANL, Los Alamos, New Mexico, USA
  • D.K. Bohler
    SLAC, Menlo Park, California, USA
  • A.L. Edelen, S.V. Milton
    CSU, Fort Collins, Colorado, USA
 
  Particle accelerators are being designed and operated over a wide range of complex beam phase space distributions. For example, the Linac Coherent Light Source (LCLS) upgrade, LCLS-II, is considering complex schemes such as two-color operation [1], while the plasma wake field acceleration facility for advanced accelerator experimental tests (FACET) upgrade, FACET-II, is planning on providing custom tailored current profiles [2]. Because of uncertainty due to limited diagnostics and time varying performance, such as thermal drifts, as well as collective effects and the complex coupling of large numbers of components, it is impossible to use simple look up tables for parameter settings in order to quickly switch between widely varying operating ranges. Several forms of artificial intelligence are currently being investigated in order to enable accelerators to quickly and automatically re-adjust component settings without human intervention. In this work we discuss recent progress in applying neural networks and adaptive feedback algorithms to enable automatic accelerator tuning and optimization.
[1] A. A. Lutman et al., Nat. Photonics 10.11, 745 (2016).
[2] V. Yakimenko et al., IPAC2016, Busan, Korea, 2016.
 
slides icon Slides THYGBE1 [14.261 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBE1  
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THYGBE3 RF Controls for High-Q Cavities for the LCLS-II LLRF, cavity, cryomodule, EPICS 2929
 
  • C. Serrano, K.S. Campbell, L.R. Doolittle, G. Huang, A. Ratti
    LBNL, Berkeley, California, USA
  • R. Bachimanchi, C. Hovater
    JLab, Newport News, Virginia, USA
  • A.L. Benwell, M. Boyes, G.W. Brown, D. Cha, G. Dalit, J.A. Diaz Cruz, J. Jones, R.S. Kelly, A. McCollough
    SLAC, Menlo Park, California, USA
  • B.E. Chase, E. Cullerton, J. Einstein-Curtis, J.P. Holzbauer, D.W. Klepec, Y.M. Pischalnikov, W. Schappert
    Fermilab, Batavia, Illinois, USA
  • L.R. Dalesio, M.A. Davidsaver
    Osprey DCS LLC, Ocean City, USA
 
  Funding: This work was supported by the LCLS-II Project and the U.S. Department of Energy, Contract n. DE-AC02-76SF00515.
The SLAC National Accelerator Laboratory is building LCLS-II, a new 4 GeV CW superconducting (SCRF) Linac as a major upgrade of the existing LCLS. The LCLS-II Low-Level Radio Frequency (LLRF) collaboration is a multi-lab effort within the Department of Energy (DOE) accelerator complex. The necessity of high longitudinal beam stability of LCLS-II imposes tight amplitude and phase stability requirements on the LLRF system (up to 0.01% in amplitude and 0.01° in phase RMS). This is the first time such requirements are expected of superconducting cavities operating in continuous-wave (CW) mode. Initial measurements on the Cryomodule test stands at partner labs have shown that the early production units are able to meet the extrapolated hardware requirements to achieve such levels of performance. A large effort is currently underway for system integration, Experimental Physics and Industrial Control System (EPICS) controls, transfer of knowledge from the partner labs to SLAC and the production and testing of 76 racks of LLRF equipment.
 
slides icon Slides THYGBE3 [14.389 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBE3  
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THYGBF3 Challenges of FAIR Phase 0 operation, MMI, experiment, storage-ring 2947
 
  • M. Bai, A. Adonin, S. Appel, R. Bär, M.C. Bellachioma, U. Blell, C. Dimopoulou, G. Franchetti, O. Geithner, P. Gerhard, L. Groening, F. Herfurth, R. Hess, R. Hollinger, H.C. Hüther, H. Klingbeil, A. Krämer, S.A. Litvinov, F. Maimone, D. Ondreka, N. Pyka, S. Reimann, A. Reiter, M. Sapinski, B. Schlitt, G. Schreiber, M. Schwickert, D. Severin, R. Singh, P.J. Spiller, J. Stadlmann, M. Steck, R.J. Steinhagen, K. Tinschert, M. Vossberg, G. Walter, U. Weinrich
    GSI, Darmstadt, Germany
 
  After two-year's shutdown, the GSI accelerators plus the latest addition of storage ring CRYRING, will be back into operation in 2018 as the FAIR phase 0 with the goal to fulfill the needs of scientific community and the FAIR accelerators and detector development. Even though GSI has been well known for its operation of a variety of ion beams ranging from proton up to uranium for multi research areas such as nuclear physics, astrophysics, biophysics, material science, the upcoming beam time faces a number of challenges in re-commissioning its existing circular accelerators with brand new control system and upgrade of beam instrumentations, as well as in rising failures of dated components and systems. The cycling synchrotron SIS18 has been undergoing a set of upgrade measures for fulfilling future FAIR operation, among which many measures will also be commissioned during the upcoming beam time. This paper presents the highlights of the challenges such as re-establishing the high intensity heavy ion operation as well as parallel operation mode for serving multi users. The status of preparation including commissioning results will also be reported.  
slides icon Slides THYGBF3 [2.952 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THYGBF3  
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THPAF041 Uncontrolled Longitudinal Emittance Blow-Up during RF Manipulations in the CERN PS impedance, cavity, emittance, simulation 3056
 
  • A. Lasheen, H. Damerau, G. Favia
    CERN, Geneva, Switzerland
 
  The CERN Proton Synchrotron (PS) determines the basic bunch spacing for the Large Hadron Collider (LHC) by means of rf manipulations. Several rf systems in a frequency range from 2.8 MHz to 200 MHz are available for beam acceleration and manipulations. Each of the six bunches injected from the PS Booster is split in several steps into 12 bunches spaced by 25 ns, yielding a batch of 72 bunches at transfer to the Super Proton Synchrotron (SPS). In the framework of the LHC Injector Upgrade (LIU) project the bunch intensity must be doubled. However, with most of the planned upgrades already in place this intensity has not yet been achieved due to collective effects. One of them is uncontrolled longitudinal emittance blow-up during the bunch splittings. In this contribution, measurements of the blow-up during the splitting process are presented and compared with particle simulations using the present PS impedance model. Beam-based measurements of the impedances of the rf cavities have been performed. They revealed that to reproduce the instability an additional impedance source is required in the PS impedance model.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF041  
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THPAF042 Improvement of the Longitudinal Beam Transfer from PS to SPS at CERN cavity, acceleration, emittance, proton 3060
 
  • A. Lasheen, H. Damerau, J. Repond, M. Schwarz, E.N. Shaposhnikova
    CERN, Geneva, Switzerland
 
  The beam transfer from the Proton Synchrotron (PS) to the Super Proton Synchrotron (SPS) at CERN is a critical process for the production of beams for the Large Hadron Collider (LHC). A bunch-to-bucket transfer is performed with the main drawback that the rf frequency in the SPS (200 MHz) is five times higher than the one in the PS (40 MHz). The PS bunches are therefore shortened non-adiabatically before extraction by applying a fast rf voltage increase (bunch rotation) to fit them into the short rf buckets in the SPS. However, particles with large amplitude of synchrotron oscillations in the PS longitudinal phase space are not properly captured in the SPS. They contribute to losses at the injection plateau and at the start of acceleration in the SPS. In this contribution, we present measurements and simulations performed to identify the source of the uncaptured particles. The tails of the particle distribution were characterized by applying longitudinal shaving during acceleration. Furthermore, the rotated bunch distribution was improved by linearizing the rf voltage using a higher-harmonic rf cavity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF042  
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THPAK037 Beam-Loading Transients and Bunch Shape in the Operation of Passive Harmonic Cavities in the ALS-U cavity, simulation, beam-loading, impedance 3298
 
  • Z. Pan, S. De Santis, C. Steier, C. Sun, M. Venturini
    LBNL, Berkeley, USA
  • T. Hellert
    DESY, Hamburg, Germany
  • C.-X. Tang
    TUB, Beijing, People's Republic of China
 
  The ALS-U is a major upgrade of the LBNL ALS to a diffraction limited light source. The current plan is to replace all the vacuum and magnet components while retaining the existing 500 MHz main and third-harmonic, passively operated, rf cavities, but replacement of the existing rf cavities is also being considered. A new feature, is represented by beam-loading transients associated with a beam consisting of 11 bunch trains separated by 10 ns gaps as needed to enable on-axis swap-out injection. In this paper we study these transients and the associated bunch-to-bunch phase, length, and profile variations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK037  
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THPAK050 MuSim, a User-Friendly Interface for Multiple Simulation Codes simulation, interface, proton, real-time 3330
 
  • T.J. Roberts
    Muons, Inc, Illinois, USA
 
  MuSim is a new and innovative graphical framework that permits the user to construct, explore, optimize, analyze, and evaluate nuclear, accelerator, and other particle-based systems efficiently and effectively. It is designed for both students and experienced scientists to use in dealing with the many modeling tools and their different description languages and data formats. Graphical interfaces are used throughout, making it easy to construct the system graphically, display the system with particle tracks, analyze results, and use on-screen controls to vary parameters and observe their effects in (near) real time. Such exploration is essential to give users insight into how systems behave, and is valuable to both new users and experienced system designers. The use of URL-based component libraries will encourage collabor-ation among geographically diverse teams. This project will facilitate access to advanced modeling and simulation tools for inexperienced users and provide workflow management for them and advanced users.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK050  
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THPAK087 Software-Computing System for Numerical Modelling of Beam Dynamics in Accelerators software, experiment, interface, simulation 3435
 
  • E. Krushinevskii, E. Sboeva
    Saint Petersburg State University, Saint Petersburg, Russia
  • S.N. Andrianov, A.N. Ivanov, N.V. Kulabukhova
    St. Petersburg State University, St. Petersburg, Russia
 
  The spectrum of software packages for the physics of charged particles beams is extremely wide. From most popular and effective systems can be allocated such programs as COSY Infinity, MAD X, MARYLIE, TRANSPORT. Heterogeneous individual formats of input and output data, the lack of a common and user-friendly interface and the narrow specialization of these programs poses a number of challenges for the modern researchers. It significantly reduces the effectiveness and quality of corresponding computational experiments. In this article we present a universal tool for automation and acceleration of computing experiments. The authors consider a method for developing the concept and prototype of a corresponding software package that would combine the advantages of existing (non-commercial) systems. This software will be able to unify the input and output data format for certain programs, visualize the information in various ways, provide reference and training information for "beginners". The results obtained within the developed framework will be a significant contribution both to the development of numerical and symbolical methods for solving evolution nonlinear equations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK087  
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THPAK090 Symbolic Presentation of Nonlinear Dynamic Systems in Terms of Lego-Objects quadrupole, octupole, database, dipole 3441
 
  • E. Sboeva, E. Krushinevskii
    Saint Petersburg State University, Saint Petersburg, Russia
  • S.N. Andrianov, A.N. Ivanov
    St. Petersburg State University, St. Petersburg, Russia
 
  In this paper we propose a symbolic representation of the solutions of the equations of evolution of dynamical systems in the framework of matrix formalism and Lie algebra for a number of elements of the accelerator (in particular, dipole, quadrupole and octupole) up to the 4th order. The considered solutions are Lego-objects*, which are include into the general scheme of the representation beam dynamics. It allows modeling of schemes of various accelerators and thereby to increasing performance of parametrical optimization. Let us note that the symbolic approach to solving such problems is more preferable than the numerical one, which is widely used. This leads to a reduction in the time and resources spent on solving optimization problems, as well as the ability to create universal Lego objects. The paper considers the verification of the obtained formulas from the experimental data. The corresponding Lego objects are the main components of the special software for both symbolic and numerical dynamics analysis. This software is planned to be used for modeling within the framework of the NICA accelerator project.
*S.N. Andrianov. Dynamic Modeling of Particle Beam Control Systems.
Saint Petersburg State University, 2002.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK090  
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THPAK105 Construction Progress of Two Superconducting Cyclotrons for Proton Therapy and Proton Irradiation at CIAE cyclotron, proton, cavity, extraction 3477
 
  • T.J. Zhang, S. An, H.R. Cai, L.C. Cao, X.L. Cao, T. Cui, X.L. Fu, T. Ge, P.F. Gong, F.P. Guan, L.L. Guan, S.G. Hou, B. Ji, X.L. Jia, M. Li, X.L. Li, Y.Q. Li, J. Lin, J.Y. Liu, X.T. Lu, Y.L. Lv, C. Wang, F. Wang, F. Wang, L. Wang, J.Y. Wei, S.M. Wei, J.S. Xing, G. Yang, J.J. Yang, M. Yin, Z.G. Yin, D.S. Zhang, S.P. Zhang, X. Zhen
    CIAE, Beijing, People's Republic of China
  • K. Fong
    TRIUMF, Vancouver, Canada
 
  Funding: Supported partly by the National Natural Science Foundation of China (Grant No. 11375273 and 11475269) and by the Ministry of Science and Technology under Grant 2016YFC0105300.
There are very strong demand for mid-energy of proton machine recent years due to the surging cancer patients and fast progress of the space science in China. For the applications of proton therapy and proton irradiation, the energy range of proton beam usually is from 200 MeV to 250 MeV, or even higher for astronavigation. Based on the R&D starting from 2009, two construction projects of 230 MeV and 250 MeV superconducting cyclotron, which have been implemented recently at China Institute of Atomic Energy(CIAE). That was started in Jan 2015 for the 230 MeV machine, for the program of proton therapy and space science launched by China National Nuclear Corporation (CNNC), and in Jan 2016 for the 250 MeV machine, for the program of proton therapy launched by the Ministry of Science and Technology of China (MOST). In this paper, the designs for the two SC cyclotrons and their key components, including the main magnet, SC coils, RF system, internal ion source and central region, extraction system, etc, and the construction progress of the machines will be presented.
 
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THPAK106 400 MHz Frequency/phase Detector and Counter detector, LLRF, FPGA, TRIUMF 3481
 
  • X.L. Fu, B. Ji, Z.G. Yin, T.J. Zhang
    CIAE, Beijing, People's Republic of China
  • G. Dennison
    UBC & TRIUMF, Vancouver, British Columbia, Canada
  • K. Fong, M.P. Laverty, Q. Zheng
    TRIUMF, Vancouver, Canada
 
  To enhance the performance and precision of TRIUMF Low Level RF system, a frequency/phase detector and counter based on FPGA is developed. The frequency/phase detector and counter is designed as a daughter board of the low level RF control system, and is connected to the mother board with mixed signal connectors. It sends the frequency error data to the PC though VXI databus, and provides two analog phase errors outputs. In current design, one single unit supports four channel discriminations of RF frequencies/phases. Preliminary tests show that the reported phase detector has a bandwidth of 400MHz. A unique implementation of frequency discrimination was carefully carried out to ensure the resolution can reach as high as 1Hz. The phase-frequency detector has been successfully applied to the Accelerator Cryo Module (ACM) system and the requirement of the low level RF control system is satisfied. After a long-term running test, the stability and reliability of the phase-frequency detector are verified.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK106  
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THPAK134 Dynamic Equations: The Matrix Representation of Beam Dynamic Equations Instead of Tensor Description sextupole, operation, software, octupole 3554
 
  • S.N. Andrianov, A.N. Ivanov, N.V. Kulabukhova
    St. Petersburg State University, St. Petersburg, Russia
  • Chang, S. Chang
    KAIST, Daejeon, Republic of Korea
  • J. Choi
    CAPP/IBS, Daejeon, Republic of Korea
  • E. Krushinevskii, E. Sboeva
    Saint Petersburg State University, Saint Petersburg, Russia
 
  In this paper we consider mathematical and computer modeling of nonlinear dynamics of particle beams in cyclic accelerators in terms of the matrix representation of the corresponding nonlinear differential equations. The proposed approach is different from the usual presentations of non-linear equations in the form of Taylor series. In the paper, we use the coefficients representation in the form of two-dimensional matrices. The similar approach allows us not only to significantly reduce the time spent on modeling beam dynamics but use symbolic mathematics to calculate the necessary two-dimensional matrices. This method demonstrates the effectiveness when solving problems of dynamics problems and optimization of control systems, and for evaluating the influence of various effects on the dynamics of the beam (including taking into account the spin). Using the tools of symbolic computations not only significantly increases the computational efficiency of the method, but also allows you to create databases of "ready-made" transformations (Lego-objects), which greatly simplify the process of modeling particle dynamics. Examples of solving practical problems are given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK134  
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THPAK147 Super-Period Multi-Bend Achromat Lattice with Interleaved Dispersion Bumps for the HALS Storage Ring lattice, storage-ring, sextupole, emittance 3597
 
  • Z.H. Bai, L. Wang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  We have proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps, in which two pairs of interleaved dispersion bumps are created in each lattice cell. Due to that many nonlinear effects can be effectively cancelled out within one cell and also many knobs can be used for nonlinear optimization, this MBA concept has given both large dynamic aperture (DA) and large dynamic momentum aperture in the lattice design of the Hefei Advanced Light Source (HALS). In this paper, to further enlarge DA, we extend the concept to the case of a super-period lattice consisting of two cells. In the super-period lattice, there are 1.5 pairs of bumps in each cell. A super-period 7BA lattice is preliminarily designed for the HALS, and a larger DA is obtained.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK147  
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THPAL025 New Drift-Tube Linac RF Systems at LANSCE DTL, LLRF, detector, cavity 3680
 
  • J.T.M. Lyles, R.E. Bratton, M.S. Prokop, D. Rees
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396.
LANSCE has restored the proton drift-tube linac (DTL) to high-power capability after the original RF-power tube manufacturer could no longer supply devices that consistently met our high-average power requirement. Thales TH628L Diacrodes® now supply RF power to three of the four DTL tanks. These tetrodes reused the existing infrastructure including water-cooling systems, coaxial transmission lines, high-voltage power supplies and capacitor banks. Each transmitter uses a combined pair of power amplifiers to produce up to 3- MW peak and 360- kW of mean power. A new intermediate power amplifier was simultaneously developed using a TH781 tetrode. Design and prototype testing of the high-power stages was completed in 2012, with commercialization following in 2013. Each installation was accomplished during a 4 to 5 month beam outage each year from 2014-2016. A new digital low-level RF control system was designed, built and placed into operation in 2016. The interaction of the dual power amplifiers, the I/Q LLRF, and the DTL cavities provided many challenges that were overcome. The replacement RF systems have completely met our accelerator requirements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL025  
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THPAL031 Development of a Vertical Electropolishing Facility for Nb 9-Cell Cavity cavity, niobium, cathode, site 3699
 
  • Y.I. Ida, V. Chouhan, K.N. Nii
    MGH, Hyogo-ken, Japan
  • akabori. Akabori, G.M. Mitoya, K. Miyano
    HKK, Morioka, Japan
  • Y. Anetai, F. Takahashi
    WING. Co.Ltd, Iwate-ken, Japan
  • H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
    KEK, Ibaraki, Japan
 
  Our Nb accelerating cavity vertical electropolishing (VEP) facility development group which was led by KEK started single-cell VEP facility development from 2014. This is based on horizontal electropolishing (HEP) techniques developed by KEK over 10 years and stainless steel electropolishing techniques developed by Marui over 30 years. We have reported results of Nb cavity VEP with Ninja cathode so far. In order to achieve international linear collider (ILC) construction, it is said that cost reduction and productivity improvement are necessary, however in case of 9-cell cavity, uniform inner surface polishing is difficult, as well known to predecessors. In this article, we will present the first report of VEP facility development from initial transparent plastic mock-up to improvement for Nb 9-cell cavity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL031  
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THPAL038 Phase Grouping of Larmor Electrons by a Synchronous Wave in Controlled Magnetrons electron, cavity, operation, cathode 3723
 
  • G.M. Kazakevich, R.P. Johnson
    Muons, Inc, Illinois, USA
  • V.A. Lebedev, V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
 
  A simplified analytical model based on the charge drift approximation has been developed. It considers the resonant interaction of the synchronous wave with the flow of Larmor electrons in a magnetron. The model predicts stable coherent generation of the tube above and below the threshold of self-excitation. This occurs if the magnetron is driven by a sufficient resonant injected signal (up to -10 dB). The model substantiates precise stability, high efficiency and low noise at the range of the magnetron power control over 10 dB by variation of the magnetron current. The model and the verifying experiments with 2.45 GHz, 1 kW magnetrons are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL038  
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THPAL039 Improved Magnetron Stability and Reduced Noise in Efficient Transmitters for Superconducting Accelerators SRF, cavity, feedback, experiment 3726
 
  • G.M. Kazakevich, R.P. Johnson
    Muons, Inc, Illinois, USA
  • V.A. Lebedev, V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
 
  State of the art high-current superconducting accelerators require efficient RF sources with a fast dynamic phase and power control. This allows for compensation of the phase and amplitude deviations of the accelerating volt-age in the Superconducting RF (SRF) cavities caused by microphonics, etc. Efficient magnetron transmitters with fast phase and power control are attractive RF sources for this application. They are more cost effective than traditional RF sources such as klystrons, IOTs and solid-state amplifiers used with large scale accelerator projects. However, unlike traditional RF sources, controlled magnetrons operate as forced oscillators. Study of the impact of the controlling signal on magnetron stability, noise and efficiency is therefore important. This paper discusses experiments with 2.45 GHz, 1 kW tubes and verifies our analytical model which is based on the charge drift approximation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL039  
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THPAL040 Lossy Beam Pipe HOM Load Ceramics with DC Conductivity experiment, vacuum, HOM, site 3729
 
  • M.L. Neubauer, A. Dudas
    Muons, Inc, Illinois, USA
  • F. Marhauser
    JLab, Newport News, Virginia, USA
 
  The ceramic materials used in the beam pipe for super-conducting RF accelerators have the problem of charging due to the electron cloud and secondary electron emission. A novel solution is in the application of conductive nanoparticles to the lossy ceramic. The lossy ceramic is pre-processed to provide for pores that will accept the conductive nanoparticles and then coated with a thin film to prevent the nanoparticles from entering the environment. The same process was also done with sub-micron carbon particles. Measurements of surface conductivity with and without a vacuum compatible sealant are reported on along with microwave measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL040  
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THPAL046 Energy-Savings for the TPS Booster RF System at the NSRRC in Taiwan booster, timing, injection, storage-ring 3748
 
  • F.-T. Chung, F.Y. Chang, L.-H. Chang, M.H. Chang, S.W. Chang, L.J. Chen, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  In this paper, we discuss an energy-savings control sys-tem for the Taiwan Photon Source (TPS) booster RF sys-tem. During top-up storage ring operation, a timing con-trol is activated to reduce the booster RF transmitter en-ergy consumption when no injection is required. When-ever injection into the TPS storage ring is needed, the booster RF transmitter is immediately adjusted to operat-ing conditions. This timing-control system will save an energy of 380, 000 kWh annually.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL046  
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THPAL049 Power Supply Decoupling Design power-supply, coupling, simulation, electron 3751
 
  • Y.T. Li, F.Y. Chang
    NSRRC, Hsinchu, Taiwan
 
  After an actual operation of the phase-shifted magnet's power supply was conducted, it was found that the currents in the two modules of magnets would be coupled each other. In order to solve this mutual coupling current, a decoupling controller is designed. From the experiment results indicate that it does not only solve the issue of coupling current but also shorten the rising time of the power supply current. This helps to increase the power supply bandwidth.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL049  
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THPAL050 Beam Dynamics of the First Beams for the IFMIF-EVEDA RFQ Commissioning operation, storage-ring, synchrotron, site 3754
 
  • C.S. Chen, W.S. Chan, Y.Y. Cheng, Y.-C. Chung, C.Y. Liu, Y.-H. Liu, Z.-D. Tsai
    NSRRC, Hsinchu, Taiwan
 
  Since December 31th 2014, the first synchrotron light from Taiwan Photon Source (TPS) was stored in the storage ring, the challenge to operate both Taiwan Light Source (TLS) and TPS smoothly and reliably became a significant issue for all members in NSRRC. On the one hand, the beam quality of former TLS must not been impaired due to the occupied resources by TPS, on the other hand, the most efforts were devoted to achieving steady operation of TPS. In order to operate both ring stably, some mutual backup structures were designed in the compressed air system and the chilled water system between TLS and TPS. The primary advantage of these mutual backup systems is minimizing the risk of beam-trip while any one of the utility system fails. Secondly, the mutual backup structures provide more flexible usage to accomplish energy conservation. From both risk-reduction and energy conservation points of view, the backup systems will do a great deal of good in the future.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL050  
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THPAL051 The Data Acquisition on Vibration Evaluation for Ice Water Pumps Systems in TPS data-acquisition, status, synchrotron, operation 3757
 
  • Y.-H. Liu, C.-S. Chen, Y.-C. Chung, Z.-D. Tsai
    NSRRC, Hsinchu, Taiwan
 
  The vibration status is a critical problem for the utility system, especially for those continuously operate deionized and cooling water pumps used in synchrotron accelerator. The purpose of this paper is to evaluate the vibration level and spectrum condition for TPS water pump systems. In order to predictive maintenance before pump systems fail, the vibration monitoring system was constructed. After vibration test for several months, the alignment of some of the ice water pumps were found mismatched because of poor system positioning and operate continuously. Besides, the ice water pump were redundantly operated and switch over every Monday morning. The recorded data showed the system sometimes switch fail because of control status or system stability. Thus, the water pump systems were repaired and maintained base on vibration monitoring system. There is still some remain problems for ice water pump systems. The utility systems could prevent malfunction through regular vibration inspection and daily data acquisition.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL051  
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THPAL054 Modification of a Power Supply for Low-Alpha Operation in the Taiwan Photon Source power-supply, operation, interface, MMI 3766
 
  • Y.S. Wong, Huang, J.C. Huang, C.Y. Liu, K.-B. Liu, B.S. Wang
    NSRRC, Hsinchu, Taiwan
 
  In this paper we describe the modifications of power supplies needed to operate the storage ring with a low momentum compaction factor (low alpha) to generate short x-ray pulses. This design includes an external polarity reversal circuit in quadrupole and sextupole magnet power supplies. The polarity reversal circuit contains four relay module where each relay can receive signals from the D-type analog interface. The power supply control system must be enhanced to switch output polarity. The operating principle and analyses of polarity reversal are discussed in more detail. Finally, a prototype polarity reversal circuit with 30 V, 250 A and 7.5 kW output power is implemented in the laboratory to verify the expected performance for the TPS low alpha operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL054  
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THPAL062 The New 20 kA 80 V Power Supply for the 520 MeV H Cyclotron at TRIUMF power-supply, TRIUMF, software, electronics 3792
 
  • S. Carrozza, L. Bondesan, A. Morato, M.P. Pretelli, G.T. Taddia
    OCEM, Valsamoggia, Italy
  • M.C. Bastos, J.-P. Burnet, G. Hudson, Q. King, G. Le Godec, O. Michels
    CERN, Geneva, Switzerland
  • Y. Bylinskii, A.C.M. Leung, W. L. Louie, F. Mammarella, R.B. Nussbaumer, C. Valencia
    TRIUMF, Vancouver, Canada
 
  The new 20 kA, 80 V power supply for the main magnet of the 520 MeV H Cyclotron at TRIUMF was awarded to OCEM. It has replaced the original system (commissioned in 1976) based on a series pass regulator. The final acceptance tests have demonstrated the com-pliance with the project specifications, especially for the high current stability required for the Cyclotron operation. The current stability is ±5 ppm, including current ripple, for a period of more than 8 hours of continuous operation. In addition, the magnetic field can be further stabilized us-ing feedback of a flux loop signal. OCEM designed the power supply to use the third gen-eration of Function Generator/Controller (FGC3) control electronics from CERN. This was chosen to obtain the high current stability required by TRIUMF. This collaboration was facilitated through a Knowledge Transfer agreement between CERN and OCEM. The power supply commis-sioning has been performed as a collaboration between OCEM, TRIUMF and CERN. This paper describes the topology of the power supply, the control electronics, the high-precision current measure-ment system and the associated software as well as the commissioning results carried out with the magnet.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL062  
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THPAL064 Burst-Mode UV Enhancement Cavity for Laser-Assisted Hydrogen Ion Beam Stripping at SNS cavity, laser, resonance, experiment 3799
 
  • A. Rakhman, Y. Liu
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This work has been supported in part by U.S. DOE grant DE-FG02-13ER41967. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
Recent success of laser-assisted charge exchange for 10 µs duration Hydrogen ion beams at SNS motivates laser development necessary for efficient stripping of 1.0 ms duration beam at full duty cycle. To overcome the laser power challenge, the interaction point was chosen inside an optical cavity. A doubly-resonant enhancement cavity and a novel locking technique have been developed, and a coherent enhancement of 402.5 MHz, 50 ps, 1.05 MW peak power ultraviolet (355 nm) laser pulses operating at 10-μs/10-Hz burst mode has been demonstrated. This will enable 1.0 ms duration laser macropulses at 60 Hz to be stored inside such a cavity to achieve efficient stripping at SNS.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL064  
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THPAL083 A Test Facility for Developments in Ion Source Plasma Power Supplies power-supply, plasma, ion-source, electronics 3845
 
  • R.E. Abel, D.C. Faircloth, S.R. Lawrie, J.H. Macgregor, M. Perkins
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  A new test facility is being designed and constructed at the ISIS spallation neutron source, Rutherford Appleton Laboratory, for the purpose of developing and experimenting with new plasma power supply topologies and modes of operation. The test facility will allow better control of power supply parameters such as discharge pulse current and plasma ignition voltage along with the possibility for closed loop feedback control. The design and technical construction details are presented with an overview of the plasma power supply developments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL083  
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THPAL105 Lower Critical Field Measurement System of Thin Film Superconductor experiment, simulation, SRF, embedded 3882
 
  • H. Ito
    Sokendai, Ibaraki, Japan
  • C.Z. Antoine
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Four
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • H. Hayano, T. Kubo, T. Saeki
    KEK, Ibaraki, Japan
  • R. Ito, T. Nagata
    ULVAC, Inc, Chiba, Japan
  • Y. Iwashita, R. Katayama, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Oikawa
    Utsunomiya University, Utsunomiya, Japan
 
  Funding: The work is supported by Japan Society for the Promotion of Science Grant-in-Aid for Young Scientist (A) No.17H04839.
Superconducting thin film is the promising technology to increase the performance of SRF cavities. The lower critical field Hc1, which is one of the important physical parameters characterizing a superconducting material, will be enhanced by coating Nb with thin film superconductor such as NbN. To investigate the performance of thin film, we developed the Hc1 measurement system using the third harmonic response of applied AC magnetic field. The measurement system consists of helium cryostat with two of GM refrigerators, sample Cu stage, solenoid coil Cu mount, solenoid coil, temperature sensors, and liquid helium level meter. AC magnetic field is produced by a coil which is driven by function generator and power amplifier at around 1 kHz. In order to control the temperature of the sample stage and coil mount, the depth of thermal anchors attached to the stage and the mount can be moved by the motor. By this temperature control the sample state can be easily transferred from Meissner state to mixed state. So that the measurement is repeated for various applied magnetic field, and the transition curve can be made. In this report, performance of the measurement system is described.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL105  
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THPAL106 Heating Unit Controller at NSRC SOLARIS TANGO, vacuum, undulator, PLC 3885
 
  • W.T. Kitka, P. Bulira, P. Czernecki, M.K. Fa'owski, K. Kubal, P. Kurdziel, A.M. Marendziak, M.P. Nowak, M. Ostoja-Gajewski, M. Rozwadowski, K. Wawrzyniak, Z. Zbylut
    Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
 
  Solaris is a third generation light source constructed at the Jagiellonian University in Kraków, Poland. The machine was designed by the MAX IV Laboratory team. Commissioning of the machine was accomplished at 2016 April and now synchrotron operate in decay mode. Two beamlines PEEM/XAS and UARPES were installed and now are being commissioned. Three more PHELIX, XMCD and diagnostic beamline have received funding and it will be installed and commissioned in range of next few years. The SOLARIS Heating Unit Controller (HUC) was designed to perform bake-out process of new installed vacuum systems. It will allow to perform activation process of undulator vacuum chamber inner coated with NEG layer and also activation process of NEG strips installed in dipole vacuum chambers. HUC is able to control independently up to six 2 kW temperature channels and two current channels. System was built based on Allen-Bradley PLC and Tango Controls. Easy access to the device is provided by the GUI design based on Taurus framework.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL106  
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THPAL115 The Design of 1.1 MW RF Dummy Load for the RF System of 520 MeV Cyclotron simulation, cyclotron, TRIUMF, pick-up 3911
 
  • N.V. Avreline, Y. Bylinskii, B. Jakovljevic, Y. Ma, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
 
  The RF System of 520-MeV Cyclotron is operating at 23 MHz with 1 MW CW RF power. The RF dummy load is required to troubleshoot and tune the RF amplifier. The RF system is being constantly improved and the future goal is to increase cyclotron's beam current up to 400 μA, which requires increasing the RF amplifier's power. As a part of this goal, a new RF dummy load was designed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL115  
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THPAL129 Magnetron Sputtering of Nb3Sn for SRF Cavities cavity, SRF, site, target 3946
 
  • MNS. Sayeed, H. Elsayed-Ali
    ODU, Norfolk, Virginia, USA
  • G.V. Eremeev, M.J. Kelley, C.E. Reece
    JLab, Newport News, Virginia, USA
  • M.J. Kelley, U. Pudasaini
    The College of William and Mary, Williamsburg, Virginia, USA
  • M.J. Kelley
    Virginia Polytechnic Institute and State University, Blacksburg, USA
 
  Nb3Sn is a potential candidate for surface material of SRF cavities since it can enable the cavity to operate at higher temperatures with high quality factor and at an increased accelerating gradient. Nb-Sn films were deposited using magnetron sputtering of individual Nb and Sn targets onto Nb and sapphire substrates. The as-deposited films were annealed at 1200 °C for 3 hours. The films were characterized for their structure by X-ray Diffraction (XRD), morphology by Field Emission Scanning Electron Microscopy (FESEM), and composition by Energy Dispersive X-ray Spectroscopy (EDS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The surface resistivity was measured down to cryogenic temperature to determine the superconducting transition temperature and its width. The composition of the multilayered films was controlled by varying the thickness of the Nb and Sn layers. The films showed crystalline Nb3Sn phases with Tc up to 17.6 K.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL129  
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THPAL143 Commissioning of JLab Vertical Cavity Processing System for SRF Nb Single Cell and Multicell Cavity With HF-Free Pulse-Reverse Electopolishing cavity, SRF, niobium, MMI 3978
 
  • H. Tian, M. Lester, J. Musson, H.L. Phillips, C.E. Reece, C. Seaton
    JLab, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177
Pulse reversed electropolishing of niobium SRF cavities, using a dilute aqueous H2SO4 electrolyte without HF yields equivalent RF performance with traditional EP. Comparing with present EP process for Nb SRF cavity which uses 1:10 volume ratio of HF (49%) and H2SO4 (98%), pulse reverse EP (also known as bipolar EP (BPEP)) is ecologically friendly and uses relatively benign electrolyte options for cavity processing. In this study, we report the commissioning of a new vertical cavity processing system for SRF Nb single cell and multi-cell cavities with HF-free pulse-reverse electropolishing at Jefferson Lab, together with RF test of cavities being processed. We report the scale-up challenges and interpretations from process R&D to implementation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL143  
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THPAL145 Magnetron R&D toward the Amplitude Modulation Control for SRF Accelerator injection, cavity, simulation, SRF 3986
 
  • R.A. Rimmer, T. E. Plawski, H. Wang
    JLab, Newport News, Virginia, USA
  • A. Dudas, S.A. Kahn, M.L. Neubauer
    Muons, Inc, Illinois, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and SBIR grant DE-SC0013203
The scheme of using a high efficiency magnetron to drive a superconducting radio frequency (SRF) accelerator cavity needs not only the injection phase locking but also the amplitude modulation to compensate the cavity's microphomics caused cavity voltage change and the beam loading variation. To be able to do a fast and efficient modulation, the magnetron's magnetic field has to be trimmed by an external coil to compensate the frequency pushing effect due to the anode current change [1]. A low eddy current magnetron body has been designed and built [2]. This paper will present the analytical prediction, simulation and experimental results on the 2.45 GHz magnetron test stand with the modulation frequency up to 1 kHz. In addition, the progresses on the injection lock to a copper cavity, new 1497 MHz magnetron prototype, 13 kW high power magnetron test stand development and newly built low level RF (LLRF) controller for the amplitude modulation will be reported.
[1] M. Neubauer et al, THPIK123, Proceedings of IPAC 2017, Copenhagen, Denmark
[2] S. A. Kahn et al, THPIK121, Proceedings of IPAC 2017, Copenhagen, Denmark
 
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THPAL150 Development of Tsinghua X-Band High Power Test Facility klystron, vacuum, GUI, software 3999
 
  • M.M. Peng, D.Z. Cao, W. Gai, Y.L. Jiang, J. Liu, J. Shi, P. Wang
    TUB, Beijing, People's Republic of China
 
  The X band high power test facility consists of a 11.424 GHz, 50 MW CPI klystron and a ScandiNova pulse modulator at Tsinghua University has been built since Sept 2017 and the output RF power has reached 60 MW with 200 ns pulse width at a repetition frequency of 10. The klystron output RF pulse will eventually be 50 MW at a 1.5 μs. A group of cylinder pulse compressor will be installed. High gradient accelerating structures for research and TTX will be tested on this facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL150  
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THPMF006 Control of the Nonlinear Dynamics for Medium Energy Synchrotron Light Sources lattice, storage-ring, optics, synchrotron 4037
 
  • J. Bengtsson, R. Bartolini, H. Ghasem, B. Singh
    DLS, Oxfordshire, United Kingdom
  • A. Streun
    PSI, Villigen PSI, Switzerland
 
  MAX-IV has introduced a paradigm shift in the design philosophy for the "Engineering-Science" in the quest for a diffraction limited Synchrotron Light Source. Similarly, SLS-2 has introduced a systematic method for controlling the Linear Optics beyond some 20 years of TME inspired paper designs; by introducing Reverse Bends to disentangle dispersion and focusing, which enables Longitudinal Gradient Bends to efficiently reduce the emittance. Similarly, we outline a systematic approach for how to control the Nonlinear Dynamics for these systems, by a method that was pioneered for the conceptual design of the Swiss Light Source in the mid-1990s; subsequently benchmarked and validated by the commissioning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF006  
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THPMF025 Emittance Measurements at FAST Facility emittance, MMI, linac, electron 4100
 
  • J. Ruan, D.R. Broemmelsiek, D.J. Crawford, A.L. Edelen, J.P. Edelen, D.R. Edstrom, A.H. Lumpkin, P. Piot, A.L. Romanov, R.M. Thurman-Keup
    Fermilab, Batavia, Illinois, USA
  • P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: *Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The FAST facility at Fermilab recently been commissioned has demonstrated the generation of electron beam within a wide range of parameter (energy, charge) suitable for accelerator-science and beam-physics experiments. This accelerator consists of a photo-electron gun, injector, ILC-type cryomodules, and multiple downstream beam-lines. It will mainly serve as injector for the upcoming Integrable Optical Test Accelerator (IOTA). At the same time we will also carry out a LINAC based intense gamma ray experiment based on the Inverse Compton scattering. It is essential to understand the beam emittance for both experiments. A number of techniques are used to characaterizing the beam emittance including slit based method and quad scan method. An on-line emittance measurement based on multi-slit method is developed so the emittance measured will be immediately available to support further beam optimization. In this report we will present the results from the emittance studies using this tool. We will also present the emittance measurement based on quads scan technique for the high energy beam line.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF025  
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THPMF029 Novel MCP-Based Electron Source Studies electron, laser, gun, cathode 4107
 
  • V.D. Shiltsev, G. Stancari
    Fermilab, Batavia, Illinois, USA
  • M.J. Haughey
    Edinburgh University, Edinburgh, United Kingdom
 
  Microchannel plates were recently proposed as cathodes for electron guns, as part of a novel electron lens design to be tested in the IOTA facility at FNAL. We experimentally assessed the suitability of microchannel plate technology in this design and studied the microchannel plate based photomultiplier (MCP-PMT) system using different sources of light pulses. Here we present the results of the nanosecond time response tests and the maximum current density tests as well as the dependency on the magnetic field strength. Several ideas how to proceed beyond O(100 mA/cm2) density observed in the first tests.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF029  
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THPMF045 Synchronized Beam Position Measurement for SuperKEKB Injector Linac linac, electron, EPICS, operation 4159
 
  • M. Satoh, F. Miyahara, T. Suwada
    KEK, Ibaraki, Japan
  • T. Kudou, S. Kusano
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
  • T. Ohfusa, H.S. Saotome, M. Takagi
    Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
 
  Toward SuperKEKB project, the injector linac upgrade is ongoing for aiming at the stable beam operation with low emittance and high intensity bunch charge. One of the key challenges is a low emittance preservation of electron beam because the vertical emittance of 20 mm.mrad or less should be transported to the main ring without a damping ring. For this purpose, the fine alignment of accelerator components is a crucial issue since the linac alignment was badly damaged by the big earthquake in 2011. From the simulation results of emittance growth, the alignment of the quadrupole magnets and accelerating structures should be conducted at the level of 300 um in rms along the 600-m-long linac. In addition, we are aiming at the level of 100 um alignment in rms within the short range distance of 100 m long. Even after the fine component alignment can be achieved, the fine beam orbit manipulation is necessary for low emittance preservation. For these reasons, we have developed the new BPM readout system based on VME64x. The new system has improved the precision of beam position measurement up to 3 um from 25 um. We will describe the software development of the new BPM readout system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF045  
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THPMK031 Elliptically Polarizing Undulator Design for PAL-XFEL undulator, FEL, operation, electron 4362
 
  • S.J. Lee, J.H. Han, D.E. Kim
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Funding: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2017R1C1B1012852).
Elliptically polarizing undulator (EPU) is under consideration as after-burner for the PAL-XFEL soft X-ray beamline to control the FEL polarization. In the soft X-ray line, seven planar undulators with a 35 mm period and 5 m length are in operation. To provide a polarization control of the FEL in the 1 to 3 nm wavelength, we compare the two types of EPUs, APPLE-II, and APPLE-X. The K value ranges for various operation modes are numerically studied for two undulator periods, 35 and 40 mm, of these EPU types.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK031  
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THPMK032 RADFET Installation at PAL-XFEL Undulator undulator, radiation, FEL, operation 4366
 
  • J.H. Han, Y.G. Jung, D.E. Kim, S.J. Lee, G. Mun
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Two undulator beamlines, one hard X-ray and one soft X-ray, are in operation at PAL-XFEL. Radiation produced during the FEL operation may impair the magnetic property of the undulator magnets and affect the FEL performance. Accumulated radiation at the undulator sections is being measured by using optically stimulated luminescent dosimeters (OSLDs) once per few months. Over 10 Gy gamma ray was detected at some locations at both undulator beamlines. However, in the measurement using the OSLDs we do not have information on which accelerator operation modes produce such high level of radiation on the undulators. To measure accumulated radiation in real time, we installed radiation-sensing field-effect transistors (RADFETs). We report the characteristics of the RADFET sensors and the installation at the PAL-XFEL undulator beamlines.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK032  
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THPMK033 PAL-XFEL Linac RF System Status klystron, operation, electron, FEL 4369
 
  • H.-S. Lee, Heo, J.Y. Heo, J.H. Hong, H.-S. Kang, K.H. Kim, S.H. Kim, D.H. Na, S.S. Park, Y.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Funding: Ministry of Science and ICT
The PAL-XFEL Linear Accelerator began user support in March 2017 after one year of RF conditioning in 2016. The energy jitter was 0.013% when operating the H-X linear accelerator with 46 modulators, Klystron, LLRF, SSA and vacuum system at 6.838 GeV energy during user support period. So far, we have replaced four klystrons and 10 thyratron switches. We also measured the influence of temperature changes of RF components according to repetition rates of the machine. We will report on the measurement results of this operating experience and performance.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK033  
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THPMK046 Advanced Fresh-Slice Beam Manipulations for FEL X-Ray Applications electron, laser, undulator, free-electron-laser 4387
 
  • A.A. Lutman, Y. Ding, M.W. Guetg, Z. Huang, J. Krzywinski, J.P. MacArthur, A. Marinelli, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  • C. Emma
    UCLA, Los Angeles, USA
 
  The recent development of the Fresh-slice technique granted control on which temporal slice lases in each undulator section in an X-ray Free-electron laser. Fresh-slice has been used for several experiments at the Linac Coherent Light Source for the generation of customizable high power two-color beams, and increased the performance of self-seeding schemes. As a novel development of the technique we present the demonstration of multistage self-amplified spontaneous-emission amplification schemes for the production of high-power ultra short pulses and improved control of the temporal duration of each pulse in multi-pulse schemes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK046  
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THPMK049 New Geometrical-Optimization Approach using Splines for Enhanced Accelerator Cavities' Performance cavity, impedance, simulation, accelerating-gradient 4395
 
  • M.H. Nasr, S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Over the past decades accelerator scientists made a huge effort in advancing the technology of particle accelerators, which lead to state-of-the-art fabrication techniques as well as simulation tools. Combining these advancements with the large boosting in computing speed provides large flexibility and motivation to investigate new accelerator geometries. In this paper, we describe a new optimization approach for the geometry of accelerating cells. This approach uses a set of control points with variable positions to control a non-uniform rational B-spline (NURBS), which describes the cavity shape. The positions of the control points are then optimized using differential-evolution optimization to maximize/minimize a defined optimization function, which is defined by the user and depends on the cavity parameters such as the shunt impedance, wall losses, peak surface fields…etc. This optimization approach leads to accelerator geometries with enhanced performance and very smooth surface fields.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK049  
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THPMK059 Commissioning of Front End of CLARA Facility at Daresbury Laboratory cathode, gun, cavity, MMI 4426
 
  • D. Angal-Kalinin, A.D. Brynes, R.K. Buckley, S.R. Buckley, J.A. Clarke, L.S. Cowie, K.D. Dumbell, D.J. Dunning, B.D. Fell, P. Goudket, A.R. Goulden, S.A. Griffiths, F. Jackson, S.P. Jamison, J.K. Jones, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, T.C.Q. Noakes, T.J. Price, M.D. Roper, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, R.J. Smith, E.W. Snedden, N. Thompson, C. Tollervey, R. Valizadeh, D.A. Walsh, T.M. Weston, A.E. Wheelhouse, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.D. Brynes, J.A. Clarke, L.S. Cowie, K.D. Dumbell, D.J. Dunning, P. Goudket, F. Jackson, S.P. Jamison, J.K. Jones, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, N. Thompson, R. Valizadeh, A.E. Wheelhouse, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • R.J. Cash, R.F. Clarke, G. Cox, G.P. Diakun, A. Gallagher, K.D. Gleave, M.D. Hancock, J.P. Hindley, C. Hodgkinson, A. Oates, J.T.G. Wilson
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  CLARA (Compact Linear Accelerator for Research and Applications) is a Free Electron Laser (FEL) test facility being developed at STFC Daresbury Laboratory. The principal aim of CLARA is to test advanced FEL schemes which can later be implemented on existing and future short wavelength FELs. The installation of the Front End (FE) section of CLARA, a S-bend merging with existing VELA (Versatile Electron Linear Accelerator) beam line and installation of a high repetition rate RF gun on VELA was completed in 2017. First beam commissioning results and high level software developments are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK059  
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THPMK092 SOLEIL Status Report operation, storage-ring, synchrotron, undulator 4516
 
  • L.S. Nadolski, G. Abeillé, Y.-M. Abiven, P. Alexandre, F. Bouvet, F. Briquez, P. Brunelle, A. Buteau, N. Béchu, M.-E. Couprie, X. Delétoille, T. Didier, J.M. Dubuisson, C. Herbeaux, N. Hubert, C.A. Kitegi, M. Labat, J.-F. Lamarre, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, F. Marteau, A. Nadji, R. Nagaoka, P. Prigent, F. Ribeiro, K.T. Tavakoli, M.-A. Tordeux, M. Valléau
    SOLEIL, Gif-sur-Yvette, France
 
  SOLEIL is both a synchrotron light source and a research laboratory at the cutting edge of experimental techniques dedicated to matter analysis down to the atomic scale, as well as a service platform open to all scientific and industrial communities. This French 2.75 GeV third generation synchrotron light source provides today extremely stable photon beams to 29 beamlines (BLs) complementary to ESRF. We report facility performance, ongoing projects and recent major achievements. A significant work was performed in order to secure the operation of the two canted 5.5 mm in-vacuum cryogenic permanent magnet undulators (CPMUs). Major R&D areas will also be discussed, and progress towards a lattice baseline for making SOLEIL a diffraction limited storage ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK092  
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THPMK104 High Power and High Repetition Rate X-band Power Source Using Multiple Klystrons klystron, GUI, MMI, network 4552
 
  • M. Volpi, M.J. Boland, P.J. Giansiracusa, T.G. Lucas, R.P. Rassool
    The University of Melbourne, Melbourne, Victoria, Australia
  • N. Catalán Lasheras, A. Grudiev, G. McMonagle, I. Syratchev, B.J. Woolley, W. Wuensch, V. del Pozo Romano
    CERN, Geneva, Switzerland
  • J. Paszkiewicz
    University of Oxford, Oxford, United Kingdom
  • C. Serpico
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • A. Vnuchenko
    IFIC, Valencia, Spain
 
  In July 2016, the first X-band test facility operating with two interwoven, 6 MW klystron pulses was commissioned at CERN. Outputting up to 46 MW after pulse compression, the new test stand allows testing of two structures concurrently with repetition rates up to 400 Hz in each line. RF commissioning of all four lines has been completed and testing of high gradient accelerating structures for the Compact Linear Collider has commenced. Operations have been ongoing for more than a year, where dedicated control algorithms have been developed to conditioning the structure and to keep the pulse compressors tuned. Significant progress has been made in understanding the conditioning of two structures that are sharing an interlock and vacuum system. The high repetition rate is already showing the significantly reduced time needed to condition accelerating structures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK104  
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THPMK145 Evaluation of Coherent Terahertz Radiation Generated from Tilted Electron Beams Aiming for Higher Light Intensity radiation, electron, target, gun 4642
 
  • M. Brameld, K. Sakaue, Y. Tadenuma, M. Washio, R. Yanagisawa
    Waseda University, Tokyo, Japan
  • R. Kuroda, Y. Taira
    AIST, Tsukuba, Japan
 
  Funding: This work was supported by a research granted from The Murata Science Foundation and JSPS KAKENHI 26286083.
When a target medium is irradiated by electron beams travelling at relativistic speed, terahertz(THz) radiation is produced by Cherenkov radiation. THz radiation is released at an angle to the direction of travel of the electron beams, and the coherence of the radiation can be improved by tilting the electron beams to match this angle, resulting in higher light intensity. The Cherenkov angle differs according to the refraction index of the target medium. At Waseda University, the generation of high-quality electron beams by a Cs-Te Photocathode RF-Gun and its applications are being researched. By utilizing the RF-Deflector, the tilt angle of the electron beam can be controlled to achieve coherent THz radiation. To gain higher light intensity, the use of Silicon and Aerogel as a target medium was challenged and compared to the conventional medium TOPAS. The THz radiation produced from the three target mediums were analyzed by use of the power meter and time domain spectroscopy(TDS). At this conference, the generation of THz Cherenkov radiation from different target mediums and the measurement results will be reported along with future perspectives.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK145  
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THPML028 Genetic Algorithms for Machine Optimization in the Fair Control System Environment software, ion-source, framework, dipole 4712
 
  • W. Geithner, Z. Andelkovic, S. Appel, O. Geithner, F. Herfurth, S. Reimann, G. Vorobjev
    GSI, Darmstadt, Germany
  • F. Wilhelmstötter
    emarsys, Vienna, Austria
 
  Due to the massive parallel operation modes at the GSI accelerators, a lot of accelerator setup and re-adjustment have to be made by the operators during a beam time. With the FAIR project the complexity of the accelerator facility increases furthermore and for efficiency reasons it is recommended to establish a high level of automation for future operation. The PEP (parameter evolution project) has been launched at GSI operations group in 2017 to investigate the potential of a settings optimization using evolutionary Algorithms. The working proof of principle has already been tested at the Cryring injector. The latest improvements and the further Development of the Parameter Evolution Project will be shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML028  
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THPML060 Virtual VELA-CLARA: The Development of a Virtual Accelerator simulation, EPICS, lattice, software 4773
 
  • T.J. Price, H.M. Castaneda Cortes, D.J. Dunning, J.K. Jones, B.D. Muratori, D.J. Scott, B.J.A. Shepherd, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R.F. Clarke, G. Cox
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  A Virtual Accelerator (VA) has been developed to mimic the accelerators Versatile Electron Linear Accelerator (VELA) and Compact Linear Accelerator for Research and Applications (CLARA). Its purpose is to test control room applications, run start-to-end simulations with multiple simulation codes, accurately reproduce measured beam properties, conduct 'virtual experiments'and gain insight into ‘hidden beam parameters'. This paper gives an overview into the current progress in constructing this VA, detailing the areas of: developing a 'Virtual EPICS' control system, using multiple simulation codes (both particle tracking and analytic), the development of a ‘Master Lattice' and the construction of a Python interface in which to run the VA.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML060  
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THPML069 The Control System Design of SCLF interface, network, data-acquisition, software 4800
 
  • Y.B. Yan, J.G. Ding, G.Y. Jiang, Y.B. Leng
    SSRF, Shanghai, People's Republic of China
  • J.F. Chen
    SINAP, Shanghai, People's Republic of China
 
  The high-gain free electron lasers have given scientists hopes for new scientific discoveries in many frontier research areas. The Shanghai Coherent Light Facility (SCLF) was proposed by the central government of China on April 2017, which is a quasi-continuous wave hard X-ray free electron laser facility. The control system is responsible for the facility-wide device control, data acquisition, machine protection, high level database or application, as well as network and computing platform. It will be mainly based on EPICS to reach the balance between the high performance and costs of maintenance. The latest technology will be adopted for the high repetition rate data acquisition and feedback system. The details of the control system design will be reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML069  
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THPML073 Measurement of the RF Reference Phase Stability in the SuperKEKB Injector LINAC linac, klystron, feedback, booster 4815
 
  • N. Liu
    Sokendai, Ibaraki, Japan
  • D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
 
  The SuperKEKB injector is a more than 600 m J-shaped LINAC. The requirement of the RF phase refer-ence stability is 0.1 degree (RMS) at 2856 MHz for SuperKEKB PHASE-2 commissioning. In order to clari-fy and improve the reference line performance, the RF reference phase stability is measured. The phase noise of the RF reference at each sector is shown in this paper. A new phase monitor system is implemented to measure the short-term stability and long-term drift due to the temperature and humidity fluctuations in the klystron gallery.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML073  
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THPML075 MYRRHA Control System Development interface, GUI, software, framework 4823
 
  • R. Modic, M. Pavleski, T. Zagar
    Cosylab, Ljubljana, Slovenia
  • J. Belmans, P. Della Faille, D. Vandeplassche
    Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium
 
  MYRRHA ADS (Accelerator Driven System), the prototype of a nuclear reactor driven by a particle accelerator, is being realized through a staged approach. This paper will explore the Control System (CS) strategy for the current stage of the accelerator R&D, where the goal is injector for the energies up to 5.9 MeV. Accelerator components are being delivered within international semi-industrial partnerships. Currently the RFQ, MYRRHA's first RF structure, is being introduced. It will be followed by the first Medium Energy Beam Transport (MEBT1) and several normal-conducting CH cavities. As the portfolio and number of devices and systems grows there is increased push towards standardization of integration procedures, interfaces to system-wide services, configuration management. Several partners provide components with varying level of vertical integration. The responsibility of the Control System integrator is therefore shifting towards provision of integration guidelines, configuration and deployment of central services and management tools, training to the contributing developers, help with specifications and requirements, quality insurance and acceptance criteria.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML075  
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THPML076 Design of Control System for Dual-Head Radiation Therapy radiation, linac, electron, Ethernet 4826
 
  • H.S. Kim, J.-S. Chai, M. Ghergherehchi, D.H. Ha, J.C. Lee, H. Namgoong, J.H. Seo, Shin, S.W. Shin
    SKKU, Suwon, Republic of Korea
  • D. Lipka
    DESY, Hamburg, Germany
 
  Sungkyunkwan University groups have been developed advanced radiation therapy machine named dual-head radiation therapy gantry for reducing the treatment time by up to 30%. The main difference between previous radiation therapy machine is using two electron LINAC as X-ray sources at radiation therapy. In support of this system, control system based on SCADA and hardware development was implemented. The control system consists of supervisory computers and local controllers and the control network was ethernet and software was written by labVIEW. An overview of this control system is presented in paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML076  
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THPML078 Web-Based Control Room Applications at TRIUMF TRIUMF, interface, multipole, operation 4832
 
  • C.B. Barquest, P. M. Jung, S. Kiy, K.E. Lucow, T. Planche, S.D. Rädel, B.E. Schultz, D. Sehayek, O. Shelbaya, D. Tattan
    TRIUMF, Vancouver, Canada
  • M. Corwin, S. Marcano
    UW/Physics, Waterloo, Ontario, Canada
 
  Control room applications are programs that interface with control systems and beam physics models. These tools range from real-time diagnostic visualizations to post-processing data analysis. At TRIUMF, the concept of web-based control room applications has been adopted to advance the capabilities of these applications and facilitate operations. This online model takes advantage of server-based continuous integration and a centralized middleware layer. Continuous integration of server-based applications allows for easy deployment and maintenance. A centralized middleware layer allows a single application to work for many different accelerator configurations. Some motivating examples of web-based applications currenly being developed are presented, demonstrating this online approach to be an effective method for deploying applications for use in the control room and beyond.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML078  
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THPML082 Reflected Power Based Extremum Seeking Control Algorithm to Tune the Resonance Frequency of Room Temperature Cavities cavity, resonance, TRIUMF, ISAC 4844
 
  • R. Leewe, K. Fong, Z. Shahriari
    TRIUMF, Vancouver, Canada
  • M. Moallem
    SFU, Surrey, Canada
 
  A sliding mode extremum seeking algorithm to tune the resonance frequency was implemented in two of TRIUMF's DTL tanks. The tuning algorithm searches for the minimum reflected power point and was developed to eliminate the highly temperature dependent phase measurement, which was previously used to tune the resonance frequency. Short and long term measurement results show that the tuning algorithm compensates for the RF heating effect as well as for diurnal temperature variations. Reflected power measurements of TRIUMF's DTL tank 3 were taken for both cases of operating the phase based tuning system and the reflected power based tuning system, with an outcome of a higher tuning accuracy of the newly developed system. Another advantage is a quick cavity start up time, as the reflected power based system does not rely on a reference set point which has do be adjusted manually. The sliding mode extremum seeking control loop is currently commissioned in further room temperature cavities of the TRIUMF's ISAC I facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML082  
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THPML083 Iterative Learning Control to Cancel Beam Loading Effect on Amplitude and Phase of the Accelerating Field beam-loading, cavity, feedback, simulation 4847
 
  • Z. Shahriari, K. Fong
    TRIUMF, Vancouver, Canada
  • G. A. Dumont
    UBC, Vancouver, Canada
 
  Funding: This research is supported by TRIUMF through federal funding via a contribution agreement with the National Research Council of Canada.
Iterative learning control (ILC) is an open loop control strategy that improves the performance of a repetitive system through learning from previous iterations. ILC can be used to compensate for a repetitive disturbance like the beam loading effect in resonators. Assuming that the beam loading disturbance is identical for all iterations, the learning law can be non-causal; it can anticipate the disturbance and preemptively counteract its effect. In this work, we aim to use ILC to cancel beam loading effect on amplitude and phase. Feedback controllers are not fast enough for this purpose. A normal feed forward controller may not be sufficient as well if there is a difference between the feed forward signal and the beam loading current. Therefore, the goal is to use ILC to adaptively cancel the beam loading effect.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML083  
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THPML085 Intelligent Controls for the Electron Storage Ring DELTA network, storage-ring, electron, synchrotron 4855
 
  • D. Schirmer
    DELTA, Dortmund, Germany
 
  In recent years, artificial intelligence has become one of the buzzwords in the field of controlling, monitoring and optimizing complex machines. Particle accelerators belong to this class of machines in particular. In accelerator controls one has to deal with a variety of time-varying parameters, nonlinear dynamics as well as a lot of small, compounding errors. Therefore, to cope with these tasks and to achieve higher performance, particle accelerators require new advanced strategies in controls and feedback systems. Machine learning through (deep) neural networks, genetic algorithms, swarm intelligence and adaptive controls are some of the proposed approaches. Increased computational capability and the availability of large data sets in combination with better theoretical understanding of new network architectures and training paradigms allow for promising approaches for novel developments. This report aims to discuss the state of the art techniques and presents ideas for possible applications of intelligent controls at the synchrotron radiation source DELTA.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML085  
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THPML088 Cavity Impedance Reduction Strategies During Multi Cavity Operation in the SIS100 High Intensity Hadron Synchrotron cavity, emittance, resonance, acceleration 4863
 
  • D. Mihailescu Stoica, D. Domont-Yankulova
    Technische Universität Darmstadt (TU Darmstadt, RMR), Darmstadt, Germany
  • D. Domont-Yankulova, H. Klingbeil
    TEMF, TU Darmstadt, Darmstadt, Germany
  • H. Klingbeil, D.E.M. Lens
    GSI, Darmstadt, Germany
 
  Funding: Supported by GSI Helmholtzzentrum für Schwerionenforschung GmbH
The planned SIS100 heavy ion synchrotron at the GSI Helmholtzzentrum für Schwerionenforschung will possess twenty ferrite accelerating cavities in its final stage of extension. As at injection and at flat top during slow extraction of the planned acceleration cycles the RF voltage will be relatively low, not all cavities will be active in this part of operation. It is important to analyse the impact of the inactive cavities on the overall RF voltage and subsequently their implication on the longitudinal particle dynamics. Classical approaches for reducing the beam impedance consist of active detuning of the cavities to pre-described parking frequencies. The fact that two out of ten buckets have to stay empty in all SIS100 scenarios is of particular interest as additional frequency components appear in the excitatory beam current, which have to be considered when the cavity is detuned. Therefore multi-cavity particle tracking simulations, consisting of twenty cavities and their attached LLRF control systems, are carried out in order to analyse different possibilities to minimize the impact on the beam dynamics and emittance growth.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML088  
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THPML089 Tuning of 3-tap Bandpass Filter During Acceleration for Longitudinal Beam Stabilization at FAIR emittance, feedback, operation, synchrotron 4866
 
  • B.R. Reichardt, D. Domont-Yankulova
    Technische Universität Darmstadt (TU Darmstadt, RMR), Darmstadt, Germany
  • D. Domont-Yankulova, H. Klingbeil
    TEMF, TU Darmstadt, Darmstadt, Germany
  • H. Klingbeil, D.E.M. Lens
    GSI, Darmstadt, Germany
 
  During acceleration in the heavy-ion synchrotrons SIS18/SIS100 at GSI/FAIR longitudinal beam oscillations are expected to occur. To reduce longitudinal emittance blow-up, dedi- cated LLRF beam feedback systems are planned. To date, damping of longitudinal beam oscillations has been demon- strated in SIS18 machine experiments with a 3-tap filter controller (e.g. *), which is robust in regard to control pa- rameters and also to noise. On acceleration ramps the control parameters have to be adjusted to the varying synchrotron frequency. Previous results from beam experiments at GSI indicate that a proportional tuning rule for one parameter and an inversely proportional tuning rule for a second parameter is feasible, but the obtained damping rate may not be opti- mal for all synchrotron frequencies during the ramp. In this work, macro-particle simulations are performed to evaluate, whether it is sufficient to adjust the control parameters pro- portionally (inversely proportionally) to the change in the linear synchrotron frequency, or if it is necessary to take more pa- rameters, such as bunch-length and synchronous phase, into account to achieve stability and a considerable high damping rate for excited longitudinal dipole beam oscillations. This is done for single- and dual-harmonic acceleration ramps.
* H. Klingbeil et al., "A Digital Beam-Phase Control System for Heavy-Ion Synchrotrons", in IEEE Transactions on Nuclear Science, vol. 54, no. 6, pp. 2604-2610, Dec. 2007.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML089  
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THPML094 New Methods for Dispersion Measurement and Correction for 12 GeV CEBAF quadrupole, cavity, software, simulation 4882
 
  • D.L. Turner
    JLab, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
This paper discusses methods for dispersion measurement and correction for the Continuous Electron Beam Accelerator Facility (CEBAF) for the 12GeV era. New methods will be compared with methods used during the 6GeV era. New software tools which implement the new methods will be discussed, along with a method for automating dispersion measurement and correction. New dispersion measurement and correction methods and tools are being implemented to provide more deterministic results and to reduce machine setup time.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML094  
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THPML099 Phase Extraction and Stabilization for Coherent Pulse Stacking cavity, laser, FPGA, feedback 4895
 
  • Y.L. Xu, W.-H. Huang, C.-X. Tang, L.X. Yan
    TUB, Beijing, People's Republic of China
  • L.R. Doolittle, Q. Du, G. Huang, W. Leemans, D. Li, R.B. Wilcox, Y. Yang, T. Zhou
    LBNL, Berkeley, California, USA
  • A. Galvanauskas
    University of Michigan, Ann Arbor, Michigan, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics, under Contract DE-AC02-05CH11231.
Coherent pulse stacking (CPS) is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy and high average power. We model the CPS as a digital filter in the Z domain, and implement two deterministic algorithms extracting the cavity phase from limited data where only the pulse intensity is available. In a 2-stage 15-pulse CPS system, each optical cavity is stabilized at an individually-prescribed round-trip phase with 0.7 deg and 2.1 deg RMS phase errors for Stage 1 and Stage 2 respectively. Optical cavity phase control with nm accuracy ensures 1.2% intensity stability of the stacked pulse over 12 hours.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML099  
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THPML100 A High Voltage Feedforward Subsystem of Low Level RF System for the High Power RF System high-voltage, LLRF, low-level-rf, experiment 4898
 
  • Z.Y. Lin, Y. C. Du, H.Q. Feng, W.-H. Huang, CY. Song, C.-X. Tang, Y.L. Xu, J. Yang
    TUB, Beijing, People's Republic of China
  • G. Huang
    LBNL, Berkeley, California, USA
 
  The Low Level Radio Frequency control (LLRF) system measures the RF signals from the accelerator tube, compares it with the phase reference received from the timing distribution system, and provides the drive signal to the high power RF system to provide synchronized RF voltage to the electron beam. Usually, the LLRF system can achieve a ~50 fs RMS phase jitter which is limited by the microwave devices. The phase noise arise from the high voltage variation of the high power system will significantly increase phase noise from low level RF signal to high power RF. A high voltage feed forward subsystem is proposed to deal with the phase noise caused by the high voltage jitter of the modulator. The demo system is depolyed in Thomson scattering X-ray source (TTX).and the primary experiment result anaylse is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML100  
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THPML109 Control System Design for Front End Devices of IRFEL FEL, power-supply, EPICS, interface 4920
 
  • S. Xu, G. Liu, Y. Song, X.K. Sun
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  An Infrared Free Electron Laser Light (IRFEL) is being constructed at National Synchrotron Radiation Laboratory. IRFEL consists of e-gun, accelerating tube, microwave, klystron, power supply, vacuum, resonator, undulator, beam diagnosis, cooling water and other devices. The development of the control system for the front end devices of IRFEL is based on EPICS. This paper will introduce the hardware system design, Input Output Controller application, Operation Interface, data archiving and retrieval.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML109  
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THPML110 EPICS Driver for Siemens CP1616 Communication Module EPICS, real-time, network, hardware 4923
 
  • Z. Huang, G. Liu, Y. Song, X.K. Sun
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Work supported by National Natural Science Foundation of China (11375186)
Siemens communication module CP1616 is a high-performance PROFINET controller, which can support both Real-time (RT) and Isochronous Real-Time (IRT) communication. Experimental Physics and Industrial Control System (EPICS) is a wildly used distributed control system in large scientific devices. In order to integrate PROFINET protocol into EPICS environment, we developed this driver based on CP1616 and established the prototype system. This paper will describe the design of EPICS driver for CP1616 and the test result of the prototype system.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML110  
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THPML111 Test of the Tune Measurement System Based on BBQ at HLS-II Storage Ring betatron, storage-ring, ion-source, experiment 4926
 
  • L.T. Huang, F.L. Gao, P. Lu, B.G. Sun, H.Q. Wang, J.G. Wang, Q. Wang, F.F. Wu, Y.L. Yang, T.Y. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Supported by the National Science Foundation of China (Grant No. 11705203, 11575181)
The HLS-II storage ring is a crucial part of Hefei Light Source. Tune is one of the most important parameters of the electron storage ring, of which the tune measurement system is an integral component. In this paper, the design of a new tune measurement system based on BBQ (base band tune), is presented. Some experiments are performed to test this system. The new system is compared with the original system and the TBT (turn-by-turn) method respectively. The obtained results illustrate higher accuracy and higher stability for the new system. A new approach of calculating the betatron oscillation amplitude is proposed, and the betatron oscillation amplitudes in the normal running stage for the HLS-II storage ring are estimated at 95 nm (horizontal) and 60 nm (vertical).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML111  
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THPML116 AutoTuner: A General Graphical User Interface for Automated Tuning GUI, interface, target, kicker 4939
 
  • X. Huang
    SLAC, Menlo Park, California, USA
  • T. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  AutoTuner is a general graphical user interface (GUI) that we developed for automated tuning or online optimization. The GUI provides a convenient interface to select tuning knobs, objectives, and optimization algorithms and to change the tuning control parameters. Tuning setup can be created and saved for reuse. The progress of the tuning processing is plotted in real time. The tuning process can be paused, aborted, or resumed. We have tested the program for real-life accelerator tuning problems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML116  
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THPML123 The ESR Barrier-Bucket LLRF System - Design and First Results LLRF, cavity, experiment, synchrotron 4964
 
  • J. Harzheim, D. Domont-Yankulova, K. Groß, H. Klingbeil
    TEMF, TU Darmstadt, Darmstadt, Germany
  • M. Frey, H. Klingbeil, D.E.M. Lens
    GSI, Darmstadt, Germany
 
  At GSI, Darmstadt, Germany, a Barrier-Bucket (BB) RF System is currently under development for the Experimental Storage Ring (ESR). The system consists of two broadband RF cavities, each driven by a solid state amplifier, with the purpose to produce two voltage pulses per beam revolution. This will enable highly sophisticated longitudinal beam manipulations like longitudinal capture, compression and decompression or stacking of the beam. For the LLRF System, several requirements have to be fulfilled. Besides high standards concerning the pulsed gap signal quality (e.g. ringing <2.5%), the system has to provide the flexibility for adiabatic voltage ramp-up and adiabatic pulse shifting with high timing accuracy. A connection to the FAIR Central Control System (CCS) is necessary, as amplitude and phase ramp data will be provided by the CCS. In this contribution, the structure of the ESR BB LLRF system is presented together with experimental results from the first version of the system, which will be installed in the ESR in March 2018.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML123  
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THPML124 Design of Beam Position Fast-Correction Magnet Power Supply for HALS power-supply, feedback, operation, storage-ring 4967
 
  • Z.X. Shao, H. Gao, L. Wang, H.Y. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Supported by 'Hefei Advanced Light Source Pre-research Project'
Hefei Advanced Light Source (HALS) is the fourth-generation radiation light source that is being pre-researched in China. Ultra-low emittance of the beam requires higher performance of power supply system. We designed a fast correcting power supply for the beam measurement needs. We adopted the all-digital method, the current closed-loop feedback used the AD7766 with 24-bit resolution as its A/D converter. And we added the corresponding constant temperature control, chain protection, etc. The small-signal frequency response of this system can reach more than 5kHz. The detail design scheme is described in this paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML124  
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THPML127 Alignment and Installation for the FELiChEM project alignment, FEL, laser, network 4977
 
  • W. Wang, Zhang, H.T. H.T, X.Y. He, D.R. Xu
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Work supported by National Natural Science Foundation of China (11705199) and China Postdoctoral Science Foundation (2017M622024)
FELiChEM is a new experimental facility under construction at the University of Science and Technology of China. There are more than one hundred important devices to construct it, which core device is two free electron laser oscillators generating middle-infrared and far-infrared laser and covering the spectral range of 25-200μm. The optical cavity is an important component of oscillator which very sensitive to misalignment errors of the mirror, due to its near-concentric and symmetric structure. High precision alignment and installation is necessary to ensure the smooth implementation of the FELiChEM project. Laser tracker and Level are used to install this devices according to the alignment control network. An efficient and high-precision alignment method based on autocollimator and photoelectric auto-collimator is used to align optical cavity of oscillator. This methods is proven to be effective and meet the tolerances by multiple means.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML127  
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THPML129 Deposition and Characterization of TiZrHfV films by DC Magnetron Sputtering vacuum, electron, storage-ring, target 4983
 
  • X.Q. Ge, T.L. He, X.T. Pei, Y.G. Wang, Y. Wang, W. Wei, B. Zhang, Y.X. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  The new generation of accelerators places higher demands on the surfaces of vacuum chamber materials. Search for low secondary electron yield (SEY) materials and an effective vacuum chamber surface treatment process, which can effectively reduce the electronic cloud effect, are important early works for the new generation of accelerators. In this work, we revealed the SEY characteristics of Ti-Zr-Hf-V NEG films and Ti-Zr-V NEG films which were deposited on Si (111) substrates using direct current magnetron sputtering method. The surface morphology and surface chemical bonding information were collected by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). With the same parameters, the maximum SEY of Ti-Zr-Hf-V NEG films and Ti-Zr-V NEG films are 1.24 and 1.51, respectively. These results are of great significance for the next-generation particle accelerators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML129  
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