Keyword: optics
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MOXGB1 Report on SuperKEKB Phase 2 Commissioning luminosity, MMI, detector, emittance 1
 
  • Y. Ohnishi
    KEK, Ibaraki, Japan
 
  The SuperKEKB electron-positron collider is being commissioned at KEK in three phases. The first phase was successfully completed in 2016, focusing on vacuum scrubbing and single beam studies without final focus optics. The second phase will start in March 2018 and until mid of July 2018. It will be dedicated to achieving the target specific luminosity larger than 4x1031 cm-2s-1/mA2, using the novel "nano-beam" collision scheme. Final focus optics will be installed, as well as the Belle-II detector, but without the vertex detector. The second phase of commissioning will also serve to assess and learn to control backgrounds induced by beam losses near the interaction region, expected to be larger than at KEKB in the past, as a result of the much smaller beams. This will be important before installing the vertex detector for the final phase of commissioning, due to start at the beginning of 2019, when high luminosity needed for data taking with the Belle-II detector should be achieved. The speaker will present the recent progress and performance of SuperKEKB that is enabled by these upgrades.  
slides icon Slides MOXGB1 [28.598 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOXGB1  
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MOPMF024 Dipole Field Quality and Dynamic Aperture for FCC-hh dipole, injection, alignment, dynamic-aperture 137
 
  • B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  • D. Boutin, A. Chancé
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • B.J. Holzer, S. Izquierdo Bermudez, D. Schoerling, D. Schulte
    CERN, Geneva, Switzerland
 
  Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Program under grant agreement No. 654305.
The Nb3Sn dipole design for the hadron machine option of the Future Circular Colliders enters in an intense and long R&D phase. As a result, more realistic dipole field quality evaluations are available for beam dynamics studies. The paper discusses the impact of the main dipole field quality on the first and second order design of the hadron machine and on its dynamic aperture.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF024  
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MOPMF025 Overview of Arc Optics of FCC-hh dipole, quadrupole, insertion, sextupole 141
 
  • A. Chancé, B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  • D. Boutin
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • B.J. Holzer, D. Schulte
    CERN, Geneva, Switzerland
 
  Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305.
The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. In this overview the status and the evolution of the design of optics integration of FCC-hh are described, focusing on design of the arcs, alternatives, and tuning procedures.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF025  
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MOPMF032 Nonlinear Correction Strategies for the LHC Using Resonance Driving Terms resonance, dipole, insertion, coupling 161
 
  • F.S. Carlier, E.H. Maclean, T. Persson, R. Tomás
    CERN, Geneva, Switzerland
 
  The correction of nonlinearities in future colliders is critical to reach operational conditions and pose a significant challenge for commissioning schemes. Several approaches have been succesfully used in the LHC to correct sextupolar and octupolar sources in the LHC insertion regions. Measurements of resonance driving terms at top energy in the LHC have improved and now offer a new observable to calculate and validate nonlinear corrections. This paper reports on measurements of resonance driving terms in the LHC and the relevant strategies used for nonlinear corrections.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF032  
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MOPMF048 Aperture Measurements with AC Dipole at the Large Hadron Collider dipole, MMI, emittance, injection 212
 
  • N. Fuster-Martínez, R. Bruce, J. Dilly, E.H. Maclean, T. Persson, S. Redaelli, R. Tomás
    CERN, Geneva, Switzerland
  • L.J. Nevay
    Royal Holloway, University of London, Surrey, United Kingdom
 
  Global aperture measurements are crucial for a safe operation and to push the performance of the LHC, in particular, the knowledge of aperture at top energy allows pushing the optics to reduce the colliding beam sizes. The standard method used in the LHC commissioning requires using several bunches for one measurement and makes bunches un-usable for other activities. This paper presents first global aperture measurements performed at injection with a new method using the AC dipole. This method consists in exciting large coherent oscillations of the beam without spoiling its emittance. A gentle control of the oscillation amplitude enables re-using the beams for several measurements. These measurements are compared with aperture measurements performed using the standard method and possible benefits, for example for optics measurements, at top energy with squeezed optics, are elaborated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF048  
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MOPMF050 LHC Operational Experience of the 6.5 TeV Proton Run with ATS Optics operation, luminosity, emittance, proton 216
 
  • M. Pojer, M. Albert, R. Alemany-Fernández, T. Argyropoulos, E. Bravin, A. Calia, G.E. Crockford, S.D. Fartoukh, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, M. Hostettler, W. Höfle, Y. Le Borgne, D. Nisbet, L. Ponce, S. Redaelli, B. Salvachua, M. Solfaroli, R. Suykerbuyk, D.J. Walsh, J. Wenninger, M. Zerlauth
    CERN, Geneva, Switzerland
 
  In May 2017, the CERN Large Hadron Collider (LHC) restarted operations at 6.5 TeV using the Achromatic Telescopic Squeeze (ATS) scheme with a target beta-star of 40 cm in ATLAS and CMS. The number of bunches was progressively increased to a maximum of 2556 with emittances of 2.5 um. In August, several machine parameters had to be re-tuned to mitigate beam loss induced instabilities and maintain a steady increase of the instantaneous luminosity. The use of a novel beam type and filling pattern produced in the injectors, allowed filling the machine with very low emittance beam (1.5 um) achieving an equivalent luminosity with 1868 bunches. In September, the beta-star was further lowered to 30 cm (using, for the first time, the telescopic technique of the ATS) and the bunch intensity pushed to 1.25·1011 protons. In the last 3 months of 2017, the LHC produced more than 500 pb-1 of integrated luminosity per day, delivering to each of the high luminosity experiments 50.6 fb-1, 10% above the 2017 target. A general overview of the operational aspects of the 2017 proton run will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF050  
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MOPMF051 LHC Operational Scenarios During 2017 Run luminosity, proton, experiment, hadron 220
 
  • B. Salvachua, M. Albert, R. Alemany-Fernández, T. Argyropoulos, E. Bravin, H. Burkhardt, G.E. Crockford, JCD. Dumont, S.D. Fartoukh, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, J.M. Jowett, Y. Le Borgne, D. Nisbet, M. Pojer, L. Ponce, S. Redaelli, M. Solfaroli, R. Suykerbuyk, D.J. Walsh, J. Wenninger, M. Zerlauth
    CERN, Geneva, Switzerland
 
  During 2017, the Large Hadron Collider LHC delivered luminosity for different physics configuration in addtion to the nominal 6.5 TeV proton-proton run. About 18.5 days were dedicated to commission and to deliver special physics to the experiments. Condifurations with large beta-star of 19 m and 24 m were prepared for luminosity calibration with Van de Meer scans. A proton-proton run at 2.51 TeV took place during the last weeks of November to provide reference data for the heavy ion (Pb-Pb, p-Pb) collisions at the same equivalent nucleon energy . A very short (0.5 days) but effective ion run was scheduled where the LHC saw the first Xe beams collissions and delivered around 3 ub-1 to ATLAS and CMS. The run ended with a low event pile-up run at 6.5TeV. This contribution summarizes the operational aspects and delivered targets for the different configurations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF051  
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MOPMF054 Comparison of Different Transverse Emittance Measurement Techniques in the Proton Synchrotron Booster emittance, extraction, proton, booster 232
 
  • G.P. Di Giovanni, S.C.P. Albright, V. Forte, M.A. Fraser, G. Guidoboni, B. Mikulec, F. Roncarolo, A. Santamaría García
    CERN, Geneva, Switzerland
 
  The measurement of the transverse emittance in an accelerator is a crucial parameter to evaluate the performance of the machine and to understand beam dynamics processes. In recent years, controlling and understanding the emittance became particularly relevant in the Proton Synchrotron Booster (PSB) at CERN as part of the LHC Injectors Upgrade (LIU). The LIU project is a necessary step to achieve the goals of the High-Luminosity LHC project. In this framework, an accurate and reliable emittance measurement of high brightness beams is mandatory to study the brightness reach of the LHC injectors. In the PSB there are two main instruments available for emittance measurements: wire scanners and secondary-emission (SEM) grids. In this paper emittance measurements performed during the 2017 physics run with these two systems are compared, taking into account various systematic error sources.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF054  
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MOPMF059 Status of the FCC-ee Top-Up Booster Synchrotron booster, collider, emittance, injection 250
 
  • B. Härer, B.J. Holzer, Y. Papaphilippou, T. Tydecks
    CERN, Geneva, Switzerland
 
  This contribution presents the status of the top-up booster synchrotron for the FCC electron-positron collider FCC-ee, which is a 100 km electron-positron collider being designed for precision studies and rare decay observations in the range of 90 to 365 GeV centre-of-mass energy. In order to keep the luminosity at a level of the order of 1035 cm-2s-1 continuous top-up injection is required, because of the short beam lifetime of less than one hour. The top-up booster synchrotron will be housed in the same tunnel as the collider rings and will ramp up the beam energy from 20 GeV at injection to the full energy between 45.5 GeV and 182.5 GeV depending on operation mode. The lattice design and two possible optics will be presented. The dynamic aperture was investigated for different sextupole schemes with and without misalignments of the lattice components. In addition, wigglers were installed to decrease the damping time and mitigate intra-beam-scattering.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF059  
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MOPMF064 High-Energy LHC Design impedance, luminosity, injection, proton 269
 
  • F. Zimmermann, D. Amorim, S. A. Antipov, S. Arsenyev, M. Benedikt, R. Bruce, M.P. Crouch, S.D. Fartoukh, M. Giovannozzi, B. Goddard, M. Hofer, R. Kersevan, V. Mertens, Y. Muttoni, J.A. Osborne, V. Parma, V. Raginel, S. Redaelli, T. Risselada, I. Ruehl, B. Salvant, D. Schoerling, E.N. Shaposhnikova, L.J. Tavian, E. Todesco, R. Tomás, D. Tommasini, F. Valchkova-Georgieva, V. Venturi, D. Wollmann
    CERN, Geneva, Switzerland
  • J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi, L. van Riesen-Haupt
    JAI, Oxford, United Kingdom
  • A. Apyan
    ANSL, Yerevan, Armenia
  • J. Barranco García, L. Mether, T. Pieloni, L. Rivkin, C. Tambasco
    EPFL, Lausanne, Switzerland
  • F. Burkart
    DESY, Hamburg, Germany
  • Y. Cai, Y.M. Nosochkov
    SLAC, Menlo Park, California, USA
  • G. Guillermo Cantón
    CINVESTAV, Mérida, Mexico
  • K. Ohmi, K. Oide, D. Zhou
    KEK, Ibaraki, Japan
 
  In the frame of the FCC study we are designing a 27 TeV hadron collider in the LHC tunnel, called the High Energy LHC (HE-LHC).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF064  
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MOPMF067 Optimized Arc Optics for the HE-LHC dipole, lattice, injection, sextupole 277
 
  • Y.M. Nosochkov, Y. Cai
    SLAC, Menlo Park, California, USA
  • M.P. Crouch, M. Giovannozzi, M. Hofer, J. Keintzel, T. Risselada, E. Todesco, R. Tomás, F. Zimmermann
    CERN, Geneva, Switzerland
  • D. Zhou
    KEK, Ibaraki, Japan
  • L. van Riesen-Haupt
    JAI, Oxford, United Kingdom
 
  Funding: Work supported by the European Commission under Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453, and the HORIZON 2020 project EuroCirCol, grant agreement 654305.
The High Energy LHC (HE-LHC) proton-proton collider is a proposed replacement of the LHC in the existing 27-km tunnel, with the goal of reaching the centre-of-mass beam energy of 27 TeV. The required higher dipole field can be realized by using 16-T dipoles being developed for the FCC-hh design. A major concern is the dynamic aperture at injection energy due to degraded field quality of the new dipole based on Nb3Sn superconductor, the potentially large energy swing between injection and collision, and the slightly reduced magnet aperture. Another issue is the field in quadrupoles and sextupoles at top energy, for which it may be cost-effective, wherever possible, to stay with Nb-Ti technology. In this study, we explore design options differed by arc lattice, for three choices of injection energy, with the goal of attaining acceptable magnet field and maximum injection dynamic aperture with dipole non-linear field errors.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF067  
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MOPMF085 Beam-gas Background Characterization in the FCC-ee IR simulation, scattering, background, vacuum 322
 
  • M. Boscolo, O.R. Blanco-García
    INFN/LNF, Frascati (Roma), Italy
  • H. Burkhardt, R. Kersevan, M. Lueckhof
    CERN, Geneva, Switzerland
  • F. Collamati
    INFN-Roma1, Rome, Italy
 
  The MDISim toolkit is used to evaluate and characterize the beam-gas induced background in the FCC-ee Interaction Region. MDISim allows a full characterization of this beam background source with the locations where the beam-gas scattering occurs as well as the loss points, as a function of different vacuum conditions and composition, for the nominal optics and parameters. Detailed pressure distribution profiles have been obtained running coupled synchrotron radiation and molecular flow montecarlo codes, as an input to the GEANT4 calculations. The particles hitting the pipe in the IR can be tracked in the detectors with a full Geant-4 simulation. Semi-analytic estimates for the expected rates and lifetime are also performed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF085  
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MOPMF086 Proposal of an Experimental Test at DAΦNE for the Low Emittance Muon Beam Production From Positrons on Target target, positron, emittance, experiment 326
 
  • M. Boscolo, M. Antonelli, O.R. Blanco-García, S. Guiducci, A. Stella
    INFN/LNF, Frascati (Roma), Italy
  • F. Collamati
    INFN-Roma1, Rome, Italy
  • R. Li Voti
    Sapienza University of Rome, Rome, Italy
  • S.M. Liuzzo, P. Raimondi
    ESRF, Grenoble, France
 
  We present in this paper the proposal of an experimental test at DAΦNE of the positron-ring-plus-target scheme foreseen in the Low EMittance Muon Accelerator. This test would be a validation of the on-going studies for LEMMA and it would be synergic with other proposals at DAΦNE after the SIDDHARTA run. We discuss the beam dynamics studies for different targets inserted in a proper location through the ring, i.e. where the beam is focused and dispersion-free. Optimization of beam parameters, thickness and material of target and optics of the target insertion are shown as well. The development of the existent diagnostic needed to test the behavior of the circulating beam is described together with the turn-by-turn measurement systems of charge, lifetime and transverse size. Measurements on the temperature and thermo-mechanical stress on the target are also under study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF086  
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MOPMK001 Optics for RF Acceleration Section for the High Energy Large Hadron Collider quadrupole, cavity, dipole, instrumentation 345
 
  • L. van Riesen-Haupt, J.L. Abelleira
    University of Oxford, Oxford, United Kingdom
  • J.L. Abelleira, E. Cruz Alaniz, P. Martinez Mirave, A. Seryi
    JAI, Oxford, United Kingdom
  • M. Hofer, F. Zimmermann
    CERN, Geneva, Switzerland
  • D. Zhou
    KEK, Ibaraki, Japan
 
  Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
As part of the FCC study, the design of the High Energy LHC (HE-LHC) is addressed. A proposed layout for the interaction region for the containing the radio frequency (RF) cavities and various beam instrumentation will be discussed. The higher energy requires more RF cavities, which strongly restricts the space available for optics and instrumentation. Another challenge arises because the beam rigidity increases whilst the LHC geometry has to be conserved. To this end, next generation dipoles have to be used in order to achieve sufficient beam to beam separation. A design that provides enough beam stay clear (BSC) in all the magnets will be presented. The design introduces an additional quadrupole on either side of the RF region to be used for phase advance adjustments that can increase the dynamic aperture.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK001  
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MOPMK003 Energy Deposition Studies and Luminosity Evolution for the Alternative FCC-hh Triplet luminosity, quadrupole, radiation, dipole 352
 
  • J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt
    JAI, Oxford, United Kingdom
  • J.L. Abelleira, E. Cruz Alaniz, L. van Riesen-Haupt
    University of Oxford, Oxford, United Kingdom
 
  Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute
The international Future Circular Collider (FCC) study comprises the development of a new scientific structure in a tunnel of 100 km. This will allow the installation of a proton collider with a centre of mass energy of 100 TeV, called FCC-hh. An alternative design of the final focus triplet for the FCC-hh has been developed in parallel to the alternative one, and adapted to the constraint of a free length (L*) of 40 m. We discuss in this paper the energy deposition issues as well as the luminosity evolution for two different optics choices: round and flat beams.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK003  
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MOPMK005 HE-LHC Final Focus: Flat Beam Parameters and Energy Deposition Studies luminosity, cavity, quadrupole, dipole 356
 
  • J.L. Abelleira, E. Cruz Alaniz, A. Seryi, L. van Riesen-Haupt
    JAI, Oxford, United Kingdom
  • J.L. Abelleira, E. Cruz Alaniz, L. van Riesen-Haupt
    University of Oxford, Oxford, United Kingdom
 
  Funding: Work supported by EuroCircol, EU's Horizon 2020 grant No 654305 & STFC grant to the John Adams Institute
The High Energy LHC (HE-LHC) project is studying the feasibility of a new proton-proton collider with a beam energy of 13.5 TeV. The nominal optics features a β* of 0.25 m and crab-cavities. Here we present a flat-beam optics that can be used with a non-zero crossing angle, in the absence of crab cavities. This is followed by energy deposition studies for the superconducting quadrupoles and dipole separators. The total dose in these magnets coming from the collision debris is evaluated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK005  
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MOPMK006 Experimental Interaction Region Optics for the High Energy LHC dipole, quadrupole, shielding, dynamic-aperture 360
 
  • L. van Riesen-Haupt, J.L. Abelleira
    University of Oxford, Oxford, United Kingdom
  • J.L. Abelleira, E. Cruz Alaniz, A. Seryi
    JAI, Oxford, United Kingdom
  • M.P. Crouch, F. Zimmermann
    CERN, Geneva, Switzerland
  • D. Zhou
    KEK, Ibaraki, Japan
 
  Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
The High Energy LHC (HE-LHC) is one option for a next generation hadron collider explored in the FCC-hh program. The core concept of the HE-LHC is to install FCC-hh technology magnets in the LHC tunnel. The higher beam rigidity and the increased radiation debris, however, impose severe challenges on the design of the triplet for the low beta insertions. In order to achieve 25 cm β* optics and survive a lifetime integrated luminosity of 10 ab-1 a new longer triplet was designed that provides sufficient shielding and enough beam stay clear. This triplet has been designed using complimentary radiation studies to optimise the shielding that will also be presented. The optics for the rest of the interaction region had to be adjusted in order to host this more rigid beam and longer triplet whilst leaving enough room for crab cavities. Moreover, the effects non-linear errors in this triplet have on the dynamic aperture will be outlined.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK006  
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MOPMK007 An Optimised Triplet for the Final Focus of the FCC-HH with a 40m Final Drift luminosity, quadrupole, collider, injection 364
 
  • L. van Riesen-Haupt, J.L. Abelleira
    University of Oxford, Oxford, United Kingdom
  • J.L. Abelleira, E. Cruz Alaniz, A. Seryi
    JAI, Oxford, United Kingdom
 
  Funding: Work supported by the Horizon 2020 project EuroCirCol, grant 654305 and by the Science and Technology Facilities Council
The sizes of the beta functions in the final focus triplet of a synchrotron collider have a great impact on the chromaticity and dynamic aperture of the machine. These beta functions are proportional to the square of the length of the final drift so it is desirable to keep it as short as possible whilst leaving enough room for the experiment. In the latest design of the FCC-hh this drift was reduced from 45 m to 40 m. In the following an alternative final focus for this new design will be presented. The effects this change has on the interaction region will examined and discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK007  
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MOPMK014 Resistive-Wall Impedance of Insertions for FCC-hh impedance, insertion, experiment, lattice 378
 
  • B. Riemann, S. Khan
    DELTA, Dortmund, Germany
  • S. Arsenyev, D. Schulte
    CERN, Geneva, Switzerland
 
  Funding: This work is supported by the German Ministry of Education & Research (BMBF, funding code 05P15PERB1) and CERN (reference numbers KE3123, EDMS 1606722).
In this work, transverse and longitudinal resistive-wall impedances for beam pipes in the experiment, injection, extraction and RF systems insertion regions of the Future Hadron-Hadron Collider (FCC-hh) are computed based on contributions from different given cross sections of the surrounding (elliptical) chamber parts along the beam path, their temperature-dependent conductivities, and optical functions. An emphasis is placed on the behaviour of transverse impedance in the main experimental regions (A and G), where maximum beta values of 104 to 105 m occur in dependence of the operation mode respectively lattice configuration. Main contributions to the transverse and longitudinal impedance budget are identified, and possibilities of reducing them are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK014  
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MOPML009 New High Luminosity LHC Baseline and Performance at Ultimate Energy operation, luminosity, emittance, cavity 408
 
  • L.E. Medina Medrano
    Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
  • A. Apollonio, G. Arduini, O.S. Brüning, M. Giovannozzi, L.E. Medina Medrano, S. Papadopoulou, Y. Papaphilippou, S. Redaelli, R. Tomás
    CERN, Geneva, Switzerland
 
  Funding: Research supported by the HL-LHC project and the Beam project (CONACYT, Mexico).
The LHC machine is envisioned to operate eventually at an ultimate beam energy of 7.5 TeV at the end of LHC Run 4, i.e. after commissioning of the HL-LHC systems, a stage falling into the High Luminosity LHC (HL-LHC) era. In this paper we review the latest baseline parameters and performance, and study the potential reach of the HL-LHC with pushed optics at the ultimate beam energy. Results in terms of integrated luminosity and effective pile-up density of both the nominal (5.0×1034 cm-2 s−1) and ultimate (7.5×1034 cm-2 s−1) levelling operations are discussed
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPML009  
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TUPAF021 Identification and Removal of SPS Aperture Limitations vacuum, target, proton, injection 709
 
  • V. Kain, R. Alemany-Fernández, H. Bartosik, S. Cettour Cave, K. Cornelis, P. Cruikshank, J.A. Ferreira Somoza, B. Goddard, C. Pasquino
    CERN, Geneva, Switzerland
 
  The CERN SPS (Super Proton Synchrotron) serves as LHC injector and provides beam for the North Area fixed target experiments. Since the 2016 run automated local aperture scans have been performed with the main focus on the vertical plane where limitations typically arise due to the flat vacuum chambers in most SPS elements. For LHC beams the aperture limitations with the present low integer tune optics also occur at locations with large dispersion. Aperture measurements in the horizontal plane using a variety of techniques were performed and showed surprising results, which could partially explain the unexpected losses of high intensity LHC beams at the SPS flat bottom. In this paper, reference measurements from 2016 are compared with the ones taken at the beginning of the run in 2017. Several aperture restrictions in the vertical plane could be found and cured, and a potential systematic restriction in the horizontal plane has been identified. The results of the measurements and the origin of the restrictions are presented in this paper, and the outlook for partial mitigation is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF021  
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TUPAF022 Studies of a New Optics With Intermediate Transition Energy as Alternative for High Intensity LHC Beams in the CERN SPS proton, multipole, dipole, sextupole 713
 
  • M. Carlà, H. Bartosik, M.S. Beck, K.S.B. Li, M. Schenk
    CERN, Geneva, Switzerland
  • M. Schenk
    EPFL, Lausanne, Switzerland
 
  The LHC injector upgrade project calls for a twofold increase in intensity of the SPS proton beam. In this paper, we present studies with a new SPS optics called Q22, which has a transition energy in between the one of the operationally used Q20 and Q26 optics. This new optics provides a compromise between the stability of Q20, due to the low transition energy, and the reduced requirements in terms of RF voltage and power in Q26. A non-linear effective model of Q22 has been extrapolated from beam based measurements and used to complement the SPS non-linear optics model. Furthermore the studies of the TMCI threshold performed so far are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF022  
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TUPAF033 Beam Optics Studies for BDF and for Tests of a Prototype Target target, extraction, emittance, proton 754
 
  • C. Heßler, M. Calviani, Y. Dutheil, M.A. Fraser, B. Goddard, V. Kain, E. Lopez Sola, F.M. Velotti
    CERN, Geneva, Switzerland
 
  Within the frame of the Physics Beyond Collider project a new fixed target facility at the SPS North Area, the so-called Beam Dump Facility (BDF), is under study. BDF requires a high intensity slowly extracted 400 GeV proton beam with 4·1013 protons per 1 s spill to achieve 4·1019 protons on target per year. This results in an exceptionally high average beam power of 355 kW on the target, which is a major challenge. To validate the target design, a test of a prototype target is planned for 2018 at an existing North Area beam line. A large part of this beam line is in common with the future BDF beam line with comparable beam characteristics and several measurement campaigns were performed in 2017 to study the optics of the line in preparation for the test. The intrinsic characteristics of the slow extraction process make the precise characterisation of the beam reaching the target particularly challenging. This paper presents beam and lattice characterisation methods and associated measurement results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF033  
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TUPAF034 LEIR Injection Efficiency Studies as a Function of the Beam Energy Distribution from Linac3 linac, injection, cavity, bunching 758
 
  • S. Hirlaender, R. Alemany-Fernández, H. Bartosik, G. Bellodi, N. Biancacci, V. Kain, R. Scrivens
    CERN, Geneva, Switzerland
 
  High intensities in the CERN Low Energy Ion Ring (LEIR) are achieved using multi-turn injections from the pre-accelerator Linac3 combined with simultaneous stacking in momentum and transverse phase spaces. Up to seven consecutive 200 μs long, 200 ms spaced pulses are injected from Linac3 into LEIR by stacking each of them into the six-dimensional phase-space over 70 turns. An inclined septum magnet allows proper filling of the transverse phase-space plane, while longitudinal stacking requires momentum variation achieved by a shift of mean momentum over time provided by phase shifting a combination of 2 RF cavities at the exit of Linac3. The achievable maximum accumulated intensity depends strongly on the longitudinal beam quality of the injected beam. The longitudinal Schottky signal is used to measure the received energy distribution of the circulating beam which is then correlated with the obtained injection efficiency. This paper presents the experimental studies to understand and further improve the injection reliability and the longitudinal stacking.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF034  
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TUPAF046 Conceptual Design of a Collimation System for the CERN Super Proton Synchrotron collimation, proton, injection, simulation 802
 
  • M. Patecki, A. Mereghetti, D. Mirarchi, S. Redaelli
    CERN, Geneva, Switzerland
 
  The Super Proton Synchrotron (SPS) is the last accelerator in the LHC Injectors Chain. Its performance is constantly being improved in frame of the LHC Injectors Upgrade (LIU) Project in order to prepare it for the future HL-LHC (High Luminosity LHC) operation. One of the LIU goals is to nearly double the intensity extracted from the SPS, up to 2.32×1011 p/bunch. In recent years, nearly 10% of losses are observed for nominal intensity and LHC-type beams; they grow to about 20% for the intensity approaching the HL-LHC target. Beam losses imply activation and aging of the SPS hardware; the possibility to add a collimation system is being considered to mitigate this problem. In this paper we present studies of a collimation system design for the SPS. The concept is based on a primary horizontal collimator located in an available position with high enough dispersion, and a secondary collimator to intercept the particles leaking out from the primary collimator. Performance of the proposed collimation system is evaluated by means of numerical simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF046  
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TUPAF051 Investigating Beam Loss Reduction with Octupoles During Slow Extraction in the CERN SPS extraction, octupole, multipole, simulation 822
 
  • L.S. Stoel, M. Benedikt, M.A. Fraser, B. Goddard
    CERN, Geneva, Switzerland
  • K.A. Brown
    BNL, Upton, Long Island, New York, USA
 
  Several different methods for reducing beam loss during resonant slow extraction at the CERN Super Proton Synchrotron (SPS) are being studied. One of these methods is the use of multipoles to manipulate the separatrices in order to reduce the fraction of protons hitting the thin wires of the electrostatic extraction septum (ES). In this paper the potential of using octupoles for this purpose is explored. Beam dynamics simulations using both a simplified model and full 6D tracking in MAD-X are presented. The performance reach of such a concept at the SPS is evaluated and the potential of future machine development studies using the octupoles already installed is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF051  
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TUPAF073 Simulation of Integrable Synchrotron with Space-charge and Chromatic Tune-shifts lattice, space-charge, simulation, synchrotron 894
 
  • J.S. Eldred, A. Valishev
    Fermilab, Batavia, Illinois, USA
 
  We present a nonlinear rapid-cycling synchrotron designed as a high-intensity replacement of the Fermilab Booster. The design incorporates integrable optics, an innovation in particle accelerator design that enables strong nonlinear focusing without generating parametric resonances. We use the Synergia space-charge tracking code to demonstrate the stability of a beam in this lattice with a space-charge tune-shift up to 0.4 and a rms momentum spread up to 0.4\%. We demonstrate the benefit of increased lattice periodicity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF073  
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TUPAF077 Beam Optics Measurements in Medium Energy Beam Transport at PIP-II Injector Test Facility quadrupole, rfq, beam-transport, emittance 909
 
  • A. Saini, J.-P. Carneiro, B.M. Hanna, L.R. Prost, A.V. Shemyakin
    Fermilab, Batavia, Illinois, USA
  • V.L. Sista
    BARC, Mumbai, India
 
  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 Proton Improvement Plan-II Injector Test (PIP2IT) is an accelerator test facility under construction at Fermilab that will provide a platform to demonstrate critical technologies and concept of the front-end of the PIP-II linear accelerator (linac). The PIP2IT warm front-end comprises a H ion source capable of delivering 15 mA, 30 keV DC or pulsed beam, a Low Energy Beam Transport (LEBT), a 162.5 MHz, CW Radio Frequency Quadrupole (RFQ) that accelerates the beam to 2.1 MeV and, a 14 m medium energy beam transport (MEBT). Presently, beamline up to the MEBT has been commissioned and operates routinely at the PIP2IT facility. In this paper, we discuss beam measurements performed at the MEBT to analyze beam emittance and its RMS sizes along the MEBT. In addition, beam based calibration of the beamline elements using differential trajectory measurement is also presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF077  
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TUPAL040 Ion Beam Studies in the FRIB Front End ion-source, space-charge, ECR, coupling 1094
 
  • T. Yoshimoto, K. Fukushima, S.M. Lidia, T. Maruta, P.N. Ostroumov, G. Pozdeyev, H.T. Ren
    FRIB, East Lansing, USA
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 and the National Science Foundation under Cooperative Agreement PHY-1102511.
The commissioning of the FRIB Front End with 12 keV/u argon beam started in the spring of 2017*. Beam profile monitors were used to evaluate RMS Twiss parameters in various locations along the beam line. Beam dynamics in the LEBT was simulated using full 3D model of beam optics elements in the tracking codes. We found a good consistency between measured and simulated data. A beam image viewer was used to measure the beam density distribution in the real space. A hollow beam structure was observed in the Ar9+ beam with the current of ~20 eμA. Extensive beam dynamics study with 3D tracking code suggests that the hollow density distribution can be generated by space charge effects of the multi-component, multi-charge state ion beam just after the ECR ion source. This paper reports studies of a mechanism that can produce a hollow beam structure.
*E. Pozdeyev, invited talk at this conference
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL040  
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TUPAL061 Target and Ion Source Development for Better Beams in the ARIEL Era ion-source, target, TRIUMF, ISOL 1155
 
  • C. Babcock, T. Day Goodacre, A. Gottberg
    TRIUMF, Vancouver, Canada
  • A. Gottberg
    Victoria University, Victoria, B.C., Canada
 
  Any ISOL facility pushing the boundaries of nuclear physics must be able to provide cutting-edge ion beams to its users - beams of isotopes far from stability, with few contaminants, that may be difficult to extract from an ISOL target. The development of these pure, exotic beams must be supported by continuing research and development on targets and ion sources. In the ARIEL era, new target/ion source geometries and operational modes will provide new opportunities which can only be exploited with time for development. To prioritize this, TRIUMF proposes to build a dedicated test stand for target and ion source research which will model the critical features of the new ARIEL target stations. This stand will provide a testing ground for methods of increasing efficiency and selectivity, such as investigations of new surface ion source [1,2] and FEBIAD ion source [3] designs. In addition, this will provide a development environment for new beams, either from new target materials, or through techniques such as extracting molecular beams. In order to maximize the gain from these investigations in on-line operation, the ion optical properties of the final beam will be investigated concurrently.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL061  
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TUZGBD4 Impact of a Wideband Feedback Prototype System on TMCI in the SPS feedback, injection, kicker, emittance 1208
 
  • W. Höfle, H. Bartosik, E.R. Bjørsvik, G. Kotzian, T.E. Levens, K.S.B. Li
    CERN, Geneva, Switzerland
  • J.E. Dusatko, J.D. Fox, C.H. Rivetta
    SLAC, Menlo Park, California, USA
  • O. Turgut
    Stanford University, Stanford, California, USA
 
  The transverse mode coupling instability (TMCI) in the SPS has been identified as one of the potential performance limitations for future high intensity LHC beams that will be required for the High Luminosity (HL)-LHC era and is being addressed by the LHC Injector Upgrade Project (LIU). A potential mitigation can be provided by wideband feedback systems with a frequency reach of about 1 GHz . For this reason, the development of a prototype system has been started in a CERN collaboration within the US-LARP framework in 2008. In this report we present latest experimental results in 2017 where this prototype system was used in single and multi-bunch studies. In particular, a successful mitigation against TMCI at injection could be demonstrated in single bunch studies.  
slides icon Slides TUZGBD4 [15.120 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUZGBD4  
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TUPMF020 Demonstration of Fast, Single-shot Photocathode QE Mapping Method Using MLA Pattern Beam laser, cathode, electron, gun 1293
 
  • E.E. Wisniewski, M.E. Conde, D.S. Doran, W. Gai, Q. Gao, W. Liu, J.G. Power, C. Whiteford
    ANL, Argonne, Illinois, USA
  • Q. Gao
    TUB, Beijing, People's Republic of China
  • G. Ha
    PAL, Pohang, Republic of Korea
  • A. Halavanau, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • P. Piot
    Fermilab, Batavia, Illinois, USA
 
  Funding: UChicago Argonne, LLC, Operator of Argonne National Laboratory ("Argonne"). Argonne, a U.S.A. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.
Quantum efficiency (QE) is the chief figure of merit in the characterization of photocathodes. Semiconductor photocathodes, especially when used in high rep-rate photo-injectors, are known to show QE degradation over time and must be replaced. The total QE is the basic diagnostic which is used widely and is easy to obtain. However, a QE map indicating variations of QE across the cathode surface has greater utility. It can quickly diagnose problems of QE inhomogeneity. Most QE mapping techniques require hours to complete and are thus disruptive to a user facility schedule. A fast, single-shot method has been proposed (citation) using a micro-lens array (MLA) generated QE map. In this paper we report the implementation of the method at Argonne Wakefield Accelerator facility. A micro-lens array (MLA) is used to project an array of beamlets onto the photocathode. The resulting photoelectron beam in the form of an array of electron beamlets is imaged at a YAG screen. Four synchronized measurements are made and the results used to produce a QE map of the photocathode.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF020  
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TUPMF039 Recommissioning of the Canadian Light Source Booster Synchrotron booster, MMI, extraction, injection 1338
 
  • W.A. Wurtz, D. Bertwistle, L.O. Dallin, X. Shen, J.M. Vogt
    CLS, Saskatoon, Saskatchewan, Canada
 
  The Canadian Light Source booster synchrotron was originally commissioned in 2002 and has worked reliably for many years. However, the operating point was not the design operating point and the booster suffered from poor quantum lifetime at the extraction energy. The low quantum lifetime caused current loss of approximately 25% in the microseconds before extraction. We have recommissioned the booster using the design optics, and the current loss before extraction is now only 6%. In this paper, we discuss the measurements and simulations involved in our recommissioning work.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF039  
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TUPMF068 Beam Dynamics on a Coupling Resonance at PETRA III resonance, coupling, lattice, injection 1417
 
  • I.V. Agapov, J. Keil, G. Kube, G.K. Sahoo, R. Wanzenberg
    DESY, Hamburg, Germany
  • Y.-C. Chae
    ANL, Argonne, Illinois, USA
  • A.I. Novokshonov
    TPU, Tomsk, Russia
 
  Working on a coupling resonance is a usual way of producing round beams in a synchrotron. The beam dynamics in this regime is however more complicated, and the emittance is sensitive to the working point, coupling correction, and bunch current drop with time, which complicates the operation. We present experience with optics setup for working on a coupling resonance in PETRA III, including linear and nonlinear beam optics characteristics, and the measurement of the horizontal and vertical beam emittances with a 2D interferometer. Beam dynamics on a coupling resonance for PETRA IV, the MBA upgrade of PETRA III currently under consideration, is also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF068  
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TUPMF075 Lattice Studies of a Booster Synchrotron for PETRA IV lattice, emittance, booster, damping 1436
 
  • H.C. Chao
    DESY, Hamburg, Germany
 
  Associated with an upgrade study of the PETRA III light source toward ultra low-emittance is an upgrade study of the booster synchrotron. One possible solution obtained from a scaling of the ALBA booster to a circumference of 300 m is considered. It is based on a modified FODO lattice with combined function magnets and achromat straights. In this paper a method utilizing piecewise matchings supervised and optimized with evolutionary algorithm (PMSOEA) was devised to search the lattice. Some preliminary results are shown and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF075  
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TUPMF089 Possible Upgrades of FLASH –- A View from the Accelerator-Perspective undulator, laser, FEL, electron 1477
 
  • M. Vogt, B. Faatz, K. Honkavaara, J. Rönsch-Schulenburg, S. Schreiber, J. Zemella
    DESY, Hamburg, Germany
 
  Recently FLASH (Free electron LASer in Hamburg) at DESY has been granted funding for a refurbishment project covering among others the replacement of two old SRF modules, an upgrade of the injector lasers and an upgrade of parts of the electron beam diagnostics. In addition we are proposing several possible upgrades and new features for the injector and the drive linac as well as in the undulator beamlines. Here we present options which are in our opinion technically feasible and at the same time operationally manageable.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF089  
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TUPMK002 First Tests of the Apple II Undulator for the LOREA Insertion Device and Front End vacuum, undulator, simulation, insertion-device 1488
 
  • J. Campmany, L.G.O. Garcia-Orta, J. Marcos, Z. Martí, V. Massana, M. Quispe
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  ALBA synchrotron is currently installing the new beamline LOREA (Low-Energy Ultra-High-Resolution Angular Photoemission for Complex Materials at ALBA). It operates in the range of 10 - 1500 eV with polarized light. To produce the light for the beamline, an Apple II undulator with a period of 125 mm has been chosen. It can operate as an undulator at low energies and as a wiggler at high energies, providing a wide energy range. The device was built by KYMA, delivered on February 2017 and installed in August 2017. We present the magnetic measurements made during SAT as well as the simulations of the influence of the ID in the electron beam dynamics and the first measurements with beam. On the other hand, the high demanding characteristics of the beamline lead to a device providing high power and wide beam in some working modes. This situation has been a challenge for the Front End (FE) thermal load. It has been built by the companies RMP and TVP, and the FE modules have been installed in the tunnel along autumn 2017. We present the Site Acceptance Tests results as well as the technical solutions adopted, especially in terms of mechanical design and used materials.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK002  
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TUPMK010 Differences in Current Dependent Tune Shifts Measured by Direct or ORM Based Methods vacuum, storage-ring, impedance, wakefield 1510
 
  • Y.E. Tan, R.T. Dowd
    AS - ANSTO, Clayton, Australia
 
  The change in the tunes as a function of total beam current is a well documented effect and has been attributed to quadrupole like self induced wakefields. Theoretical models presented by others have utilised direct methods (spectrum analyser) to measure the tunes in the analysis. In this report we shall present observations that show the ORM method, Linear Optics from Closed Optics (LOCO), and direct methods have significantly different tune gradients. The different tune gradients is attributed to the static (ORM) and dynamic (direct) nature of the measurements where in the static case the vacuum chamber is to be considered as a thin wall while in the dynamic case the vacuum chamber wall is to be considered as a thick wall.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK010  
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TUPMK011 Single Ring Permanent Magnet Lens solenoid, permanent-magnet, emittance, TRIUMF 1513
 
  • K. Jayamanna, R.A. Baartman, Y. Bylinskii, T. Planche
    TRIUMF, Vancouver, Canada
  • M. Corwin
    UW/Physics, Waterloo, Ontario, Canada
  • R.N. Simpson
    UBC, Vancouver, B.C., Canada
 
  Funding: TRIUMF receives its funding from the National Research Council of Canada.
A permanent magnet lens has been designed to be a non-powered alternative to solenoids for low energy beam transport. The lens consists of a single ring of 12 sectors, each sector with poles directed inward. This forms an axial field that reverses sign at the midpoint, somewhat like two opposing short solenoids. It is similar to the Iwashita lens* but consists of only one ring, not two. A prototype lens optimized to decrease the magnetic material required while also reducing aberration, has been built and tested for a 25 keV H-minus beam. Emittance figures measured downstream of the lens are compared with theory.
* Y. Iwashita, "Axial Magnetic Field Lens with Permanent Magnet", Proc. PAC 1993, p.3154.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK011  
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TUPMK014 Dipole Fringe Field Analysis of the NSLS-II Storage Ring dipole, storage-ring, lattice, simulation 1519
 
  • J. Choi, Y. Hidaka, T.V. Shaftan, C.J. Spataro, G.M. Wang
    BNL, Upton, Long Island, New York, USA
 
  Funding: DOE Contract No. DE-SC0012704
In the NSLS-II storage ring, the effect of the dipole fringe field is not negligible and was considered already at the design phase. Especially in the vertical direction, the standard simulation codes are using the parameter called FINT (fringe Field INTegral) and, if there is no specific information, it is usually set to 0.5 which is considered as the reasonable average. With the hall-probe measurement data of the NSLS-II storage ring dipoles, we evaluated measured FINTs and applied them to the beam simulation. The paper shows the resulting FINTs and their effects.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK014  
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TUPML014 CO2 CPA Laser Development for User Experiments in Advanced Accelerators and Radiation Sources laser, experiment, plasma, operation 1556
 
  • M.N. Polyanskiy, M. Babzien, M.A. Palmer, I. Pogorelsky
    BNL, Upton, Long Island, New York, USA
 
  The ATF* is a National User Facility for advanced research in accelerator physics and technology. The ATF's terawatt CO2 laser is a unique scientific instrument allowing researchers to explorer new particle acceleration mechanisms and to study light/matter interaction at an order-of-magnitude longer photon wavelengths compared to the majority of other laser research facilities (λ≈10μm). Continuous development over more than two decades brought the ATF's CO2 laser to the limit of peak power achievable in a conventional gas laser MOPA configuration (in ATF's amplifier geometry this is ~0.5 TW in routine operation, and up to 2 TW in some experiments). To overcome this limit, we employ, for the first time in a gas laser, a chirped-pulse amplification (CPA) scheme. The goal of our current research and development effort is to demonstrate 3-5 TW peak power at the system output and to reliably deliver a large fraction of this power as a high-quality beam to a range of user experiments. Achieving this goal will lay the ground work for implementation of a >10 TW mid-IR laser system "BESTIA" that is currently being constructed as a part of the ATF-II project.
*Accelerator Test Facility at Brookhaven National Laboratory
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML014  
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TUPML052 Characterisation of the Second Stable Orbit Generated by Transverse Resonance Island Buckets (TRIBs) resonance, experiment, emittance, simulation 1656
 
  • F. Kramer, P. Goslawski, A. Jankowiak, M. Ries, M. Ruprecht, A. Schälicke
    HZB, Berlin, Germany
 
  Funding: Federal Ministry of Education and Research
Operating the storage ring near a transverse tune resonance can generate TRIBs in the corresponding phase space, providing a second orbit twisting around the standard orbit. TRIBs as a bunch separation scheme in combination with the proposed variable bunch length storage ring BESSY VSR* represent a promising alternative to dedicated single or few bunch operation modes. The injection efficiency and stability of the two orbits at BESSY II and MLS are almost on par with and the lifetime at about 70 % of the standard user mode. Results from simulations and measurements of our present island optics will be presented. Beam parameters like the betatron motion, dispersion and emittance of both the core and island orbit will be discussed as well as the separation between the island and the core orbit. At BESSY II a dedicated test week together with the friendly users took place in the first week of February, 2018.
* A. Jankowiak et al., eds., BESSY VSR Technical Design Study, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany, June 2015. DOI: 10.5442/R0001
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML052  
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TUPML055 Beam Optics Designs of a Strecher Ring and a Transfer Line for J-PARC Slow Extraction extraction, quadrupole, sextupole, injection 1667
 
  • M. Tomizawa, R. Muto, T. Ogitsu
    KEK, Ibaraki, Japan
  • A. Konaka
    TRIUMF, Vancouver, Canada
 
  The J-PARC main ring (MR) provides 30 GeV high intensity beams for neutrino experimental facility (NU) by fast extraction and hadron experimental facility (HD) by slow extraction. It is a serious issue to ensure sufficient integrated proton number on target (POT) for each facility. A stretcher ring (ST) can solve this serious problem. A beam accelerated by the MR is transferred to the ST and is slowly extracted over several second. While the beam is slowly extracted in the ST, the MR can accelerate and deliver a beam to the NU. The ST is put above the MR and fitted in the MR tunnel. Arc sections in the ST consist of superconducting combined function magnets (dipole, quadrupole and sextupole components), and separated function quadruple and sextupole magnets (hybrid lattice). A 30 GeV beam transfer line (BT) from the MR to the ST uses superconducting combined magnets with dipole and quadrupole functions to shorten the BT. The transferred beam is injected into an arc section in the ST. The adoption of the superconducting magnets in the ST and the BT saves operation cost drastically. Beam optics designs for the ST and the BT will be described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML055  
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TUPML078 Fast Quadrupole Beam Based Alignment Using AC Corrector Excitations quadrupole, alignment, closed-orbit, synchrotron 1727
 
  • Z. Martí, G. Benedetti, U. Iriso
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  A novel method to perform Beam Based Alignment has been tested at ALBA using the 10kHz fast acquisition BPMs together with an AC excitation of the corrector magnets allowing to speed up the beam based alignment process. The former approach relies on software synchronization and tango device servers to execute a series of DC corrector magnets and quadrupoles settings designed to avoid the quadrupole hysteresis effects. The approach that we present here is simpler, gives the same level of accuracy and precision and speeds up the measurement by a factor 10. The total measurement time has changed from 5 hours to 10 minutes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPML078  
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WEXGBD2 Pulse-by-Pulse Multi-XFEL Beamline Operation with Ultra-Short Laser Pulses electron, FEL, operation, undulator 1740
 
  • T. Hara, T. Inagaki, H. Maesaka, Y. Otake, H. Tanaka, K. Togawa
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • K. Fukami
    JASRI/SPring-8, Hyogo-ken, Japan
  • T. Hasegawa, O. Morimoto, S. Nakazawa, M. Yoshioka
    SES, Hyogo-pref., Japan
  • H. Kawaguchi, Y. Kawaguchi
    Nichicon (Kusatsu) Corporation, Shiga, Japan
  • C. Kondo
    JASRI, Hyogo, Japan
 
  The parallel operation of multiple beamlines is an important issue to expand the opportunity of user experiments for linac based FELs. At SACLA, the parallel operation of three beamlines, BL1~3, has been open to user experiments since September 2017. BL1 is a soft x-ray beamline driven by a dedicated accelerator, which is a former SCSS linac, and BL2 and 3 are XFEL beamlines, which share the electron beam from the SACLA main linac. In the parallel operation, a kicker magnet with 10 ppm stability (peak-to-peak) switches the two XFEL beamlines at 60 Hz from pulse to pulse. To ensure wide spectral tunability and optimize the laser performance, the energies and lengths of the electron bunches are independently adjusted for the two beamlines according to user experiments. Since the electron bunch of SACLA has typically 10~15 fs (FWHM) in length and its peak current exceeds 10 kA, the CSR effect at a dogleg beam transport to BL2 is quite significant. In order to suppress the CSR effects, an isochronous and achromatic lattice based on two DBA structures was introduced. In this talk, the multiple XFEL beamline operation and achieved laser performance are presented.  
slides icon Slides WEXGBD2 [9.712 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEXGBD2  
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WEYGBE2 Applications of Caustic Methods to Longitudinal Phase Space Manipulation FEL, electron, linac, gun 1790
 
  • T.K. Charles
    The University of Melbourne, Melbourne, Victoria, Australia
  • T.K. Charles
    CERN, Geneva, Switzerland
  • D. Douglas
    JLab, Newport News, Virginia, USA
  • P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Longitudinal phase space management is a key feature of recirculating machines. Careful consideration of the longitudinal matching is required not only in order to ensure a high peak current, low energy spread bunch is delivered to the FEL but also to support the deceleration and energy recovery of the spent beam. In a similar manner, longitudinal phase space manipulation can be utilised for pulse shaping in bunch compression, to minimise the influence of CSR-induced emittance growth. In this paper, we present a method for longitudinal phase space matching based upon the avoidance of electron trajectory caustics. Through considering the conditions under which caustics will form, we generate exclusion plots identifying the viable parameter space at numerous positions through beam acceleration and energy recovery. The result is a method for selecting the linear momentum compaction and the higher-order momentum compaction to satisfy the non-caustic condition whilst achieving the bunch compression or lengthening as required.  
slides icon Slides WEYGBE2 [6.296 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEYGBE2  
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WEPAF036 Energy Independence in Optical Transition Radiation Imaging simulation, radiation, electron, diagnostics 1898
 
  • J. Wolfenden, R.B. Fiorito, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • R.B. Fiorito, C.P. Welsch, J. Wolfenden
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work was supported by the EU under Grant Agreement No. 624890 and the STFC Cockcroft Institute core Grant No. ST/G008248/1.
The exploitation of optical transition radiation (OTR) in imaging-based diagnostics for charged particle beams is a well-established technique. Simulations of the expected OTR transverse beam profiles are therefore important in both the design of such imaging systems and the analysis of the data. Simulating OTR images is relatively straightforward for low energy electron beams. However, in the near future electron machines will be using high-energy and low-emittance beams. Using such parameters can be challenging to simulate, and can be limiting in their account of practical factors, e.g. chromatic aberrations. In this work we show systematically that the use of low-energy parameters in high-energy OTR image simulations induces little deviation in the resulting transverse beam profiles. Simulations therefore become much easier to perform, and further analysis may be performed. This opens up exciting opportunities to perform simulations quicker and with reduced demands on the computation requirements. It will be shown in this contribution how this approach will enable enhanced ways to optimize OTR diagnostics.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF036  
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WEPAF044 Automatic Tuning of PETRA, its Injector Complex, and Prospects of Autonomous Operation of PETRA IV controls, operation, 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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WEPAF062 Machine Learning Methods for Optics Measurements and Corrections at LHC network, controls, 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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WEPAG005 Synchrotron Radiation Beam Diagnostics for the Integrable Optics Test Accelerator controls, electron, 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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WEPAK010 Simulations and Measurements of the BPM Non Linearity and Kicker Timing Influence on the Tune Shift With Amplitude (TSWA) Measurement at BESSY II kicker, simulation, factory, diagnostics 2107
 
  • F. Kramer, P. Goslawski, J.G. Hwang, A. Jankowiak, P. Kuske, M. Ruprecht, A. Schälicke
    HZB, Berlin, Germany
 
  The Tune Shift With Amplitude (TSWA) does not only determine the position of the stable fix points for the Transverse Resonant Island Buckets (TRIBs) but also represents a global observable for the nonlinear optics in general. For theoretical investigations of the TRIBs a reliable nonlinear optics of the machine is required and thus all measurable global observables for the nonlinear optics are of great interest. The measurement of the TSWA for the BESSY II standard optics was performed using an injection kicker to excite high amplitude betatron oscillations and then extract the amplitude dependant frequency from the synchrotron radiation damped oscillation with a Hilbert transformation. With TRIBs optics the injection kicker was not able to sufficienty excite the beam. The impact and correctability of the BPM nonlinearity at the reached amplitudes and the reason for the failure of the excitation method for our TRIBs optics shall be looked onto in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAK010  
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WEPAL005 Beam Size Measurement and PSF Evaluate of KB Mirror Monitor at SSRF SRF, storage-ring, electron, photon 2151
 
  • D.C. Zhu, J.S. Cao, Y.F. Sui, J.H. Yue
    IHEP, Beijing, People's Republic of China
 
  Funding: Work supported by National Nature Science Foundation of China(11605213)
A Kirkpatrick Baez mirror imaging system was designed and installed to measure the transverse beam size and emittance of SSRF storage ring. Two crossed cylindrical mirrors are used to image the dipole source point in the horizontal and vertical direction. Both mirrors could be moved in and out in order to interchangeable with an original X-ray pinhole system. Hard X-ray with peak energy of 20.5 keV was focused at the X-ray scintillator camera. Aberration and point spread function which would cause image blur were evaluated. System commissioning and optimization have been done. PSF measurement was acquired using beam based calibration scheme by varying the beam images with different quadrupole settings and fitting them with the corresponding theoretical beam sizes.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL005  
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WEPAL013 Design of the Diagnostic Stations for the ELI-NP Compton Gamma Source radiation, electron, linac, simulation 2173
 
  • M. Marongiu
    INFN-Roma, Roma, Italy
  • M. Castellano, E. Chiadroni, G. Di Pirro, G. Franzini, A. Giribono, V. Shpakov, A. Stella, A. Variola
    INFN/LNF, Frascati (Roma), Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
 
  A high brightness electron Linac is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with the laser beam in the interaction point. Electron beam spot size is measured with optical transition radiation (OTR) profile monitors. Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine. This will be useful, for instance, during the commissioning phase of the GBS in order to verify the correct functionality of the C-Band accelerating structures, due to the fact that there are OTR screens after each accelerating module. This paper deals with the studies of different optic configurations to achieve the field of view, resolution and accuracy in order to measure the energy of the beam. Several configurations of the optical detection line will be studied with simulation tools (e.g. Zemax).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL013  
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WEPAL020 Measurement of Transverse Dipole and Quadrupole Moments with the BPMS in the J-PARC 3-50 BT quadrupole, dipole, emittance, beam-transport 2197
 
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • H. Kuboki, K. Satou, M. Tejima
    KEK, Tokai, Ibaraki, Japan
 
  We measure dipole and quadrupole moments of the beam using the BPMs in the beam transport line 3-50BT of J-PARC and obtain differences of squared horizontal- and vertical-rms-sizes for those BPMs. Then we obtain rms emittances and rms momentum by fitting with given Twiss parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL020  
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WEPAL047 Online Optimisation of the MAX IV 3 GeV Ring Dynamic Aperture dynamic-aperture, sextupole, octupole, storage-ring 2281
 
  • D.K. Olsson
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  In order to improve the resilience of the MAX IV 3 GeV ring's beam to a horizontal dipole kick while at the design tunes (42.20, 16.28) the optimisation algorithm RCDS (Robust Conjugate Direction Search) was deployed. The algorithm was able to increase the horizontal acceptance by finding new settings for the sextupole and octupole magnets, whilst leaving the vertical acceptance virtually unchanged. Additionally, the optimisation increased the momentum acceptance of the lattice, increasing beam lifetime.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL047  
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WEPAL073 Enhanced Bunch Monitoring by Interferometric Electro-Optic Methods pick-up, laser, proton, polarization 2353
 
  • S.M. Gibson, A. Arteche, A. Bosco
    Royal Holloway, University of London, Surrey, United Kingdom
  • S.E. Bashforth, A. Bosco, S.M. Gibson
    JAI, Egham, Surrey, United Kingdom
  • M. Krupa, T. Lefèvre
    CERN, Geneva, Switzerland
 
  Funding: We acknowledge funding by UK STFC grant ST/N001583/1, JAI at Royal Holloway University of London and CERN
A prototype Electro-Optic Beam Position Monitor has been installed for tests* in the CERN SPS to develop the concept for high-bandwidth (6-12GHz) monitoring of crabbed-bunch rotation and intra-bunch instabilities at the High Luminosity LHC**. The technique relies on the ultrafast response of birefringent MgO:LiNO3 crystals to optically measure the intra-bunch transverse displacement of a passing relativistic bunch. This paper reports on recent developments, including a new interferometric electro-optic pick-up that was installed in the CERN SPS in September 2017; in first beam tests with nominal bunch charge, a corresponding interferometric signal has been observed. The interferometric arrangement has the advantages of being sensitive to the strongest polarisation coefficient of the crystal, and the phase offset of the interferometer is controllable by frequency scanning of the laser, which enables rapid optimisation of the working point. Novel concepts and bench tests for enhancements to the pick-up design are reviewed, together with prospects for sensitivity during the first crab-cavity beam tests at the CERN SPS in 2018.
* A. Arteche et al "First beam tests at the CERN SPS of an electro-optic beam position monitor for the HL-LHC" TUPCF23, IBIC 2017.
** HL-LHC TDR v0.1 doi.org/10.23731/CYRM-2017-004
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL073  
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THPAF019 Initial Performance of the Magnet System in the Splitter/Combiner Section of the Cornell-Brookhaven Energy-Recovery Linac Test Accelerator linac, quadrupole, dipole, cavity 2986
 
  • J.A. Crittenden, A.C. Bartnik, R.M. Bass, D.C. Burke, J. Dobbins, C.M. Gulliford, Y. Li, D. Sagan, K.W. Smolenski, Turco, J. Turco
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg
    BNL, Upton, Long Island, New York, USA
  • D. Jusic
    Cornell University, Ithaca, New York, USA
 
  Funding: This work is supported by NSF award DMR-0807731, DOE grant DE-AC02- 76SF00515, and New York State Energy Research and Development Authority.
The Cornell-Brookhaven Energy-recovery Linac Test Accelerator is a four-pass, 150-MeV electron accelerator with a six-cell 1.3 GHz superconducting-RF linear accelerator and a fixed-field alternating-gradient (FFAG) return loop made up of Halbach-style quadrupole magnets. The optics matching between the linear accelerator and the return loop is achieved with a conventional magnet system comprised of 50 dipole magnets and 64 quadrupole magnets in four beamlines at each end of the linac. The 42-, 78-, 114- and 150-MeV electron beams are separated into independent vacuum chambers in order to allow for the path-length adjustment required by energy recovery. We report on the first beam tests of the initial installation of the splitter/combiner section at the exit of the linac. The vacuum system of the 42-MeV S1 line was installed during the first week of April. Nine dipole and four quadrupole magnets were installed and surveyed into position the following week, and the water cooling system was commissioned. A 6-MeV beam passed through the line on April~11 with no need for adjusting pre-set magnet excitation currents. One week later, time-of-flight measurements were used to calibrate and phase the individual superconducting RF cavities. The S1 magnet settings were then scaled up to achieve 5-cavity, 42-MeV operation through the first nine FFAG permanent-magnet quadrupoles. This initial Fractional Arc Test will conclude on May 18, when the installation of the remaining seven splitter/combiner lines and the return loop will begin. CBETA operations are scheduled to begin in early 2019.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF019  
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THPAF021 Start to End Simulation of the CBETA Energy Recovery Linac linac, lattice, simulation, space-charge 2993
 
  • W. Lou, A.C. Bartnik, J.A. Crittenden, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg, S.J. Brooks, F. Méot, D. Trbojevic, N. Tsoupas
    BNL, Upton, Long Island, New York, USA
  • C.E. Mayes
    SLAC, Menlo Park, California, USA
 
  Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
CBETA is an energy recovery linac accelerating from 6 MeV to 150 MeV in four linac passes, using a single return line accepting all energies from 42 MeV to 150 MeV. We simulate a 6-dimensional particle distribution from the injector through the end of the dump line. Space charge forces are taken into account at the low energy stages. We compare results using field maps to those using simpler magnet models. We introduce random and systematic magnet errors to the lattice, apply an orbit correction algorithm, and study the impact on the beam distribution.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF021  
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THPAF023 The Beam Optics of the FFAG Cell of the CBETA ERL Accelerator quadrupole, focusing, linac, electron 3000
 
  • W. Lou, A.C. Bartnik, J.A. Crittenden, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg, S.J. Brooks, F. Méot, D. Trbojevic, N. Tsoupas
    BNL, Upton, Long Island, New York, USA
  • C.E. Mayes
    SLAC, Menlo Park, California, USA
 
  Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The Cornell-Brookhaven Energy Recovery Linac Test Accelerator now under construction will accelerate electrons from 6 MeV to 150 MeV in four linac passes, using a single return line accepting all energies from 42 to 150 MeV. We describe the optical design of the machine, with emphasis on recent updates. We explain how we choose parameters for the wide energy acceptance return arc, taking into account 3D field maps generated from magnet designs. We give the final machine parameters resulting from iterations between desired lattice properties and magnet design. We modified the optics to improve the periodicity of the return arc near its ends and to create adequate space for vacuum hardware. The return arc is connected to the linac with splitter lines that serve to match the optics for each beam energy. We describe how matching conditions were chosen for the splitter lines and how we use them to control longitudinal motion. We simulate the injection and low energy extraction systems including space charge effects, matching the beam properties to the optical parameters of the rest of the machine.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF023  
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THPAF034 Studies of Horizontal Instabilities in the CERN SPS simulation, octupole, damping, impedance 3032
 
  • M.S. Beck, H. Bartosik, M. Carlà, K.S.B. Li, G. Rumolo, M. Schenk
    CERN, Geneva, Switzerland
  • U. van Rienen
    Rostock University, Faculty of Engineering, Rostock, Germany
 
  In the framework of the LHC Injectors Upgrade (LIU), beams with double intensity with respect to the present values will have to be successfully accelerated by the CERN Super Proton Synchrotron (SPS) and extracted towards the Large Hadron Collider (LHC). However, first experience running with intensity higher than the nominal LHC beam has shown that coherent instabilities in the horizontal plane may develop, becoming a potential intensity limitation for the future high intensity operation. To understand the mechanism of these instabilities, the PyHEADTAIL code has been used to check if the SPS impedance model reproduces the observations. The instability growth rates have been studied for different machine models and different chromaticity settings. In addition, the effect of other stabilizing methods, like the octupoles and the transverse damper, has also been investigated. Measurements are presented to benchmark the simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF034  
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THPAF039 IP Orbit Correction Update for HL-LHC alignment, quadrupole, dipole, cavity 3048
 
  • D. Gamba, R. De Maria
    CERN, Geneva, Switzerland
 
  Funding: Research supported by the HL-LHC project.
The HL-LHC design foresees a substantial modification of the LHC layout next to the low beta Interaction Points (IPs), namely IP1 and IP5. The inner triplets will be replaced by larger aperture ones to achieve lower beta at the IPs and crab cavities (CCs) will be installed. This will add new constraints to the orbit control, which required a careful choice of location and strength of the new orbit correctors to be installed in the area. The new orbit correction system will need to correct for the unavoidable imperfections, but also provide the necessary flexibility for implementing and optimising the crossing scheme. Detailed studies of the HL-LHC layout versions HLLHCV1.0 and HLLHCV1.1 were already performed. This paper is the continuation of these works and is based on the latest layout HLLHCV1.3. A simplification of the previous analysis is proposed that helps to identify the dominant imperfections. The expected performance and tolerances of the present layout are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF039  
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THPAF045 Performance Optimisation of Turn-by-Turn Beam Position Monitor Data Harmonic Analysis betatron, lattice, software, electron 3064
 
  • L. Malina, J.M. Coello de Portugal, J. Dilly, P.K. Skowroński, R. Tomás, M.S. Toplis
    CERN, Geneva, Switzerland
  • J.M. Coello de Portugal
    UPC, Barcelona, Spain
 
  Nowadays, turn-by-turn beam position monitor data is increasingly utilized in many accelerators, as it allows for fast and simultaneous measurement of various optics parameters. The accurate harmonic analysis of turn-by-turn data costs beam time when needed online. Generally, the electronic noise is avoided by cleaning of the data based on singular value decomposition. In this paper, we exploit the cleaning procedure to compress the data for the harmonic analysis. This way the harmonic analysis is sped up by an order of magnitude. The impact on measurement accuracy is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF045  
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THPAF046 Optics Measurements in Storage Rings Based on Simultaneous 3-Dimensional Beam Excitation dipole, synchrotron, betatron, storage-ring 3068
 
  • L. Malina, J.M. Coello de Portugal
    CERN, Geneva, Switzerland
  • J.M. Coello de Portugal
    UPC, Barcelona, Spain
 
  Optics measurements in storage rings usually employ excitation in both transverse directions. This needs to be repeated at several different beam energies and is time-consuming. In this paper, we develop a new optics measurement technique, which excites the beam in all three spatial dimensions simultaneously. It allows measuring the linear optics and chromatic properties at the same time, leading to speed up of the optics measurements. The measurement method has been successfully demonstrated in the LHC using AC-dipoles and RF frequency modulation. Analysis methods have been derived for the 3-dimensional beam excitation case. We quantify the resolution of the measured optical quantities. The first results suggest that the added complexity does not deteriorate the resolution of the linear optics measurement. In the future, this method can serve as an operational tool to check the optics or even to correct it.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF046  
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THPAF067 Effects of Synchrotron Motion on Nonlinear Integrable Optics synchrotron, coupling, betatron, lattice 3131
 
  • S.D. Webb, N.M. Cook
    RadiaSoft LLC, Boulder, Colorado, USA
  • J.S. Eldred
    Fermilab, Batavia, Illinois, USA
 
  Funding: This work was supported in part by the Department of Energy, Office of Science, Office of High Energy Physics under contract number DE-SC0011340.
An integrable Rapid-Cycling Synchrotron (iRCS) has been proposed as a replacement for the Fermilab Booster to achieve multi-MW beam power for the Fermilab high-energy neutrino program.* The successful application of nonlinear integrable optics to proton synchrotrons requires careful examination of single-particle longitudinal effects, especially synchrotron motion. For example, synchrobetatron coupling may excite transverse resonances in the ring. We will use the Synergia code to simulate the effects of this synchrobetatron coupling on the iRCS design with nonlinear inserts. Our goal will be to identify new invariants in the presence of this coupling. Assuming the synchrotron tune is sufficiently small, we have identified one or more adiabatic invariants of the motion. These invariants suggest that integrable optics with synchrobetatron coupling retains integrability when averaged over a synchrotron period.
* J. Eldred and A. Valishev, "Design Considerations for Proposed Fermilab Integrable RCS," arXiv 1703.00952 (2017).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF067  
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THPAF068 Suppression of Instabilities Generated by an Anti-Damper With a Nonlinear Magnetic Element in IOTA simulation, experiment, lattice, damping 3134
 
  • E.G. Stern, J.F. Amundson, A. Macridin
    Fermilab, Batavia, Illinois, USA
 
  Funding: US Department of Energy
The Integrable Optics Test Accelerator (IOTA) storage ring is being constructed at Fermilab as a testbed for new accelerator concepts. One important series of experiments tests the use of a novel nonlinear magnetic insert to damp coherent instabilities. To test the damping power of the ele- ment, an instability of desired strength may be intentionally excited with an anti-damper. We report on simulations of beam stabilization using the Synergia modeling framework over ranges of driving and damping strengths.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF068  
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THPAF076 Using Graphic-Turtle with the Particle Beam Optics Laboratory (PBO Lab) simulation, scattering, software, quadrupole 3158
 
  • G.H. Gillespie
    G.H. Gillespie Associates, Inc., Del Mar, California, USA
 
  A Particle Beam Optics Laboratory (PBO Lab) module has been developed for the Paul Scherrer Institute (PSI) version of the TURTLE program commonly known as Graphic-Turtle. The PSI-TURTLE version extends the original TURTLE program by including several unique beam optics capabilities, as well as by providing a self-contained graphics package. The unique optics modeling, together with the data visualization enhancements, make the PSI-TURTLE program ideal for certain types of beam simulations. The PBO Lab environment provides a single graphic user interface (GUI) that features an easy-to-learn and easy-to-use drag-and-drop beamline construction kit. Underlying the GUI is a sophisticated object model developed specifically for the accelerator community. PBO Lab provides a common interface for multiple charged particle optics codes. Modules have been developed for a number of popular beam optics programs that cover a range of accelerator types and applications. The PSI-TURTLE Module extends those capabilities. The module is described and its main capabilities and limitations are summarized.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF076  
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THPAF086 Beam Dynamics Simulations for Operating a Robinson Wiggler at the MLS wiggler, operation, dynamic-aperture, storage-ring 3189
 
  • J. Li, J. Feikes, M. Ries
    HZB, Berlin, Germany
  • T. Tydecks
    CERN, Geneva, Switzerland
 
  A Robinson wiggler is planned to be installed in the storage ring of the Metrology Light Source (the MLS). The Robison wiggler (RW) is a device consisting of a chain of combined-function magnets (CFMs), intended to manipulate the damping partition numbers and thus adjust the longitudinal emittance. The objective is to lengthen the bunch in order to improve the Touschek lifetime. However, the nonlinear perturbation of the beam dynamics due to the Robinson wiggler could limit the achievable improvement. Therefore, a symplectic method of modeling the wiggler has been established to study these nonlinear effects. Optimized solutions have been developed for both the ramping procedure and the future daily operation of the wiggler and are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF086  
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THPAK004 Accurate and Efficient Tracking in Electromagnetic Quadrupoles quadrupole, dynamic-aperture, multipole, HOM 3207
 
  • T. Pugnat, B. Dalena, A. Simona
    CEA/IRFU, Gif-sur-Yvette, France
  • L. Bonaventura
    Politecnico di Milano, Milano, Italy
  • R. De Maria, J. Molson
    CERN, Geneva, Switzerland
 
  Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields nonlinearities will greatly help in the improvement of future colliders design and performance. This paper presents a study of quadrupole tracking using realistic field maps and measured or simulated longitudinal harmonics. The main goal is to describe the effect of the longitudinal dependence of high order non-homogeneity of the field in the case of the HL-LHC inner triplet.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK004  
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THPAK009 Benchmark Analyses of Electrostatic Devices for SPIRAL2-DESIR Beam Lines quadrupole, simulation, emittance, electrostatic-devices 3225
 
  • L. Perrot, M. Kemel, S. Rousselot
    IPN, Orsay, France
 
  Funding: French ANR, Investissements d'Avenir, EQUIPEX. Contract number ANR-11-EQPX-0012.
The new ISOL facility SPIRAL2 is currently being built at GANIL, Caen France. The commissioning of the accelerator is in progress since 2015. SPIRAL2 will produce a large number of new radioactive ion beams (RIB) at high intensities. In 2023, the DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation), from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions). In order to deliver the RIB to the experimental set-ups installed in the DESIR hall, 140 meters of beam line are studied since 2014. The transfert lines are today fully design and building will start in 2018. Electrostatic devices (quadrupoles, steerers and deflectors) have been intensively study using various tools. This paper will focus on the detail results of a benchmark using OPERA3D and Comsol Multiphysics apply to the DESIR quadrupole conception.
 
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THPAK020 Optics Model and Measurements of the DAΦNE Transfer Lines injection, operation, dipole, positron 3249
 
  • O.R. Blanco-García, A. De Santis, G. Di Pirro, C. Milardi, D. Pellegrini, A. Stecchi, A. Stella
    INFN/LNF, Frascati (Roma), Italy
 
  The different components of the DAΦNE accelerator complex: LINAC, Damping Ring and two colliding rings are connected by a composite system of Transfer Lines which, thanks to adaptive configurations, are able to transport electron and positron beams at 510~MeV. Recently, thanks to the introduction of new diagnostics tools, the optics model of the DAΦNE Transfer Lines has been improved and succesfully used to make the collider operations more efficient. The measurements done by using the new tools and their impact on the optics model optimization process are presented and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK020  
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THPAK035 Numerical Tools for Modeling Nonlinear Integrable Optics in IOTA with Intense Space Charge Using the Code IMPACT-Z space-charge, lattice, simulation, proton 3290
 
  • C.E. Mitchell, J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Integrable Optics Test Accelerator (IOTA) is a novel storage ring under commissioning at Fermi National Accelerator Laboratory designed to investigate the dynamics of beams with large transverse tune spread in the presence of strongly nonlinear integrable optics. Several new numerical tools have been implemented in the code IMPACT-Z to allow for high-fidelity modeling of the IOTA ring during Phase II operation with intense proton beams. A primary goal is to ensure symplectic treatment of both single-particle and collective dynamics. We describe these tools and demonstrate their application to modeling nonlinear integrable dynamics with space charge in IOTA.
 
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THPAK036 Accurate Modeling of Fringe Field Effects on Nonlinear Integrable Optics in IOTA quadrupole, octupole, betatron, lattice 3294
 
  • C.E. Mitchell, R.D. Ryne
    LBNL, Berkeley, California, USA
  • F.H. O'Shea
    RadiaBeam, Santa Monica, California, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of High Energy Physics.
The Integrable Optics Test Accelerator (IOTA) is a novel storage ring under commissioning at Fermi National Accelerator Laboratory designed to investigate the dynamics of beams with large transverse tune spread in the presence of strongly nonlinear integrable optics. Uncontrolled nonlinear effects resulting from magnetic fringe fields can affect the integrability of particle motion, and long-term numerical tracking requires an accurate representation of these effects. Surface fitting algorithms provide a robust and reliable method for extracting this information from 3-dimensional magnetic field data provided on a grid. These algorithms are applied to investigate the unique nonlinear magnetic insert of the IOTA ring, and consequences of the fringe fields to the long-term dynamics of the beam are discussed.
 
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THPAK042 On Long-Term Space-Charge Tracking Simulation space-charge, simulation, emittance, lattice 3305
 
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  The nonlinear space-charge effects in high intensity accelerator can degrade beam quality and cause particle losses. Self-consistent macroparticle tracking simulations have been widely used to study these space-charge effects. However, it is computationally challenging for long-term tracking simulation of these effects. In this paper, we study a fully symplectic self-consistent particle-in-cell model and numerical methods to mitigate numerical emittance growth. We also discuss about a fast alternative frozen space-charge model that has a potential to improve computational speed significantly.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK042  
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THPAK054 Optics Calibration and Measurement for Low Alpha Lattices in TPS Storage Ring lattice, emittance, coupling, operation 3343
 
  • F.H. Tseng, C.H. Chen, J.Y. Chen, P.C. Chiu, C.H. Huang, C.-C. Kuo, C.C. Liang, C.Y. Liao, Y.-C. Liu, H.-J. Tsai
    NSRRC, Hsinchu, Taiwan
 
  In order to provide short-pulse radiation for pump-probe experiments and coherent radiation for THz/IR measurements, we develop low alpha lattices to reduce the momentum compaction factor from nominal operation values 2.4*10-4 to 2.6*10-5 or lower. The corresponding bunch length at 2.8 MV RF voltage and zero current are from 10.78 ps to 3.55 ps or less. In the low alpha operations, the bunch lengthening as a function of bunch current, the orbit drift and noise enhancements as well as rf stability effect are observed. In this report we will present our studies on the lattice design, optics correction, beam parameters measurements and alpha measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK054  
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THPAK068 Fringe Field Effect of Solenoids solenoid, neutron, quadrupole, ECR 3385
 
  • T.V. Gorlov, J.A. Holmes
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This work has been supported by Oak Ridge National Laboratory, man-aged by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
We derive a precise analytical nonlinear transverse map for single particle transport through a solenoid with hard edge fringe fields. The transfer map is two dimensional for transverse coordinates and momenta with fixed longitudinal momentum. Because it is an accurate analytic map, it is also symplectic. The transfer map is compared with ex-act numerical tracking.
 
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THPAK082 Simulation of Perturbative Effects in IOTA simulation, lattice, octupole, emittance 3422
 
  • C.C. Hall, D.L. Bruhwiler, N.M. Cook, J.P. Edelen, S.D. Webb
    RadiaSoft LLC, Boulder, Colorado, USA
 
  The Integrable Optics Test Accelerator (IOTA) is being commissioned at Fermi National Laboratory for study of the concept of nonlinear integrable optics. The use of a special nonlinear magnetic element introduces large tune spread with amplitude while constraining the idealized dynamics by two integrals of motion. The nonlinear element should provide suppression of instabilities through nonlinear decoherence. We examine the case of a bunch injected off-axis and the resulting damping of centroid oscillations from decoherence. A simple model of the damping is described and compared to simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK082  
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THPAK083 An s-Based Symplectic Spectral Space Charge Algorithm space-charge, simulation, plasma, proton 3425
 
  • N.M. Cook, D.T. Abell, D.L. Bruhwiler, J.P. Edelen, C.C. Hall, S.D. Webb
    RadiaSoft LLC, Boulder, Colorado, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC001340.
Traditional finite-difference particle-in-cell methods for modeling self-consistent space charge introduce non-Hamiltonian effects that make long-term tracking in storage rings unreliable. Foremost of these is so-called grid heating. Particularly for studies where the Hamiltonian invariants are critical for understanding the beam dynamics, such as nonlinear integrable optics, these spurious effects make interpreting simulation results difficult. To remedy this, we present a symplectic spectral space charge algorithm that is free of non-Hamiltonian numerical effects and, therefore, suitable for long-term tracking studies. We present initial results demonstrating the implementation of the algorithm, using a spectral representation of the fields and macro particles to preserve Hamiltonian structures. We then discuss applications to the Integrable Optics Test Accelerator (IOTA), currently under construction at Fermilab.
 
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THPAK104 New Proton Driver Beamline Design for ARIEL* Project at TRIUMF** target, proton, TRIUMF, cyclotron 3473
 
  • Y.-N. Rao, R.A. Baartman, Y. Bylinskii, F.W. Jones
    TRIUMF, Vancouver, Canada
 
  Funding: ∗ Capital funding from CFI (Canada Foundation for Innovation). ** Funded under a contribution agreement with NRC (National Research Council Canada).
The new radioisotope facility at TRIUMF, ARIEL, under construction, comprises two primary driver beams: 50 MeV electrons from the SC linac and 480 MeV protons from the main TRIUMF cyclotron. New 80 m long proton beam line will transport up to 100 microamps beam from existing cyclotron extraction port to an ISOL target station. H− cyclotron stripping foil extraction allows to feed this additional user simultaneously with 3 present different experimental programs. Distinctive features of the new beam line include: a) compensation of the cyclotron energy dispersion; b) low-loss (< 1 nA/m) beam transport after a collimator dedicated to remove the beam halo produced by large-angle scattering in the extraction foil; c) broad range of beam size variability at the production target by applying beam rastering at 400 Hz; d) sharing the same tunnel with electron beam line that requires unique beam loss protect system. Details of beam optics design as well as beam instrumentation are discussed in the paper.
 
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THPAK108 Fourier Coefficients of Long-Range Beam-Beam Hamiltonian via Two-Dimensional Bessel functions resonance, lattice, emittance, TRIUMF 3486
 
  • D. Kaltchev
    TRIUMF, Vancouver, Canada
 
  The two-dimensional coefficients (resonance basis) in the Fourier expansion of the long-range beam-beam Hamiltonian have been expressed through the (less familiar) generalized modified Bessel functions of two arguments. We describe an efficient method to compute these coefficients based on the above representation. The method has been applied to HL-LHC lattices and benchmarked against MadX simulations of detuning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK108  
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THPAK135 Assessment of Linear and Non-Linear Optics Errors due to Beam-Beam with Multipoles for the High Luminosity LHC luminosity, quadrupole, hadron, beam-beam-effects 3557
 
  • L.E. Medina Medrano
    Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
  • J. Barranco García, T. Pieloni
    EPFL, Lausanne, Switzerland
  • X. Buffat, L.E. Medina Medrano, R. Tomás
    CERN, Geneva, Switzerland
 
  Funding: HL-LHC project, European Circular Energy-Frontier Collider Study, H2020 programme (Grant 654305), Swiss State Secretariat for Education, Research and Innovation (SERI), Beam project (CONACYT, Mexico).
Study of the head-on and long-range beam-beam effects in the High Luminosity LHC (HL-LHC) is of interest to evaluate their potential impact on performance (in the form of luminosity imbalance) and machine operation (collimator system), and, depending on their magnitude, correction schemes might be necessary to minimize them. In this work, both the β-beating at zero amplitude and its amplitude-dependence are computed for the current HL-LHC baseline optics and parameters, as well as the amplitude detuning, at the main interaction points and collimators. Correction of the β-beating, tune shift and footprint for the HL-LHC, as originally proposed for the LHC, via compensation of the multipolar terms of the beam-beam force with corrector magnets, is also discussed.
 
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THPAK141 Initial Tests of Nonlinear Quasi-Integrable Optics at the University of Maryland Electron Ring octupole, electron, experiment, simulation 3581
 
  • H. Baumgartner, B.L. Beaudoin, I. Haber, T.W. Koeth, D.B. Matthew, K.J. Ruisard
    UMD, College Park, Maryland, USA
 
  Funding: Funding for this project and travel is provided by DOE-HEP, NSF GRFP and NSF Accelerator Science Program.
An octupole channel has been inserted into the University of Maryland Electron Ring (UMER), in order to investigate the mitigation of destructive resonances as a novel approach in high-intensity beam transport. The individual octupole magnets have been characterized using our in-house 3-dimensional magnet mapping stage, with a measured gradient of 51.6 ± 1.5 T/m3/A. A single section (20°) of an 18-cell FODO lattice has been replaced by a longitudinally-varying octupole channel constructed from seven flexible printed circuits (PCBs). We present the design of the channel and preliminary beam based measurements on the ring.
 
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THPAK143 Tuning Low-Current Beam for Nonlinear Quasi-Integrable Optics Experiments at the University of Maryland Electron Ring lattice, octupole, experiment, quadrupole 3585
 
  • K.J. Ruisard, H. Baumgartner, B.L. Beaudoin, S. Bernal, B. M. Cannon, L. Dovlatyan, I. Haber, T.W. Koeth
    UMD, College Park, Maryland, USA
 
  Funding: Travel was supported by the NSF, the APS DPB, and TRIUMF. Funding for the work was provided through DOE-HEP Award DESC0010301, NSF Award PHY1414681 and the NSF GRFP program.
Design of accelerator lattices with nonlinear integrable optics is a novel approach to suppress transverse resonances and may be crucial for enabling low-loss high-intensity beam transport. Lattices with large amplitude-dependent tune spreads, driven by strong nonlinear magnet inserts, have reduced response to resonant driving perturbations [*]. This paper describes preparations for tests of a quasi-integrable octupole lattice at the University of Maryland Electron Ring (UMER). The planned tests employ a low-current highemittance beam with low space charge tune shift (∼ 0.005) to probe the dynamics of a lattice with large external tune spread (∼ 0.26).
* V. Danilov and S. Nagaitsev, Nonlinear accelerator lattices
with one and two analytic invariants, PRSTAB, 13, 084002, 2010.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK143  
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THPAK153 Linac Optics Correction With Trajectory Scan Data quadrupole, linac, lattice, storage-ring 3606
 
  • X. Huang, Y.-C. Chao, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  • T. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  We proposed and tested a scheme to measure and correct linac optics by scanning the beam trajectory in the horizontal and vertical phase spaces. The trajectory data are compared to tracking data in a fitting scheme, from which we can derive the quadrupole strength errors. Simulation is carried out to evaluate the requirements and the performance of the method. The method is experimentally applied to FEL linacs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK153  
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THPMF006 Control of the Nonlinear Dynamics for Medium Energy Synchrotron Light Sources lattice, controls, storage-ring, 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.  
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THPMF011 Femtosecond Laser Ablation for Manufacturing of X-ray Lenses and Phase Corrector Plates laser, photon, storage-ring, experiment 4057
 
  • S.P. Antipov
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • L. Assoufid, W.C. Grizolli, J. Qian, X. Shi
    ANL, Argonne, Illinois, USA
 
  Funding: DOE SBIR
The next generation light sources such as diffraction limited storage rings and high repetition rate free electron lasers (FELs) will generate X-ray beams with significantly increased peak and average brilliance. These future facilities will require X-ray optical components capable of handling large instantaneous and average power densities while tailoring the properties of the X-ray beams for a variety of scientific experiments. In this paper we report on research and development of a single crystal diamond compound refractive lens. Diamond lenses presented here are fabricated by fs-laser cutting and subsequent polishing. Grating interferometry measurement data of these lenses had been performed at the Advanced Photon Source (Argonne). Besides the lenses, we fabricated and tested several phase correction plates, a refractive elements designed to correct for cumulative X-ray beam aberrations.
 
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THPMF019 ESRF-EBS Lattice Model with Canted Beamlines lattice, SRF, MMI, quadrupole 4081
 
  • S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, T.P. Perron, P. Raimondi, S.M. White
    ESRF, Grenoble, France
 
  The ESRF Extremely Brilliant Source (ESRF-EBS) lattice model is updated to include three canted beamlines. The cells are modified where necessary to include 3-Pole Wiggler (3PW), 2-Pole Wiggler (2PW) and Short Bending Magnet (SBM) sources. Several lattices are obtained for the different stages that will bring from commissioning to operation with users. A scheme for tune modification keeping key optics knobs unchanged is proposed.  
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THPMF041 Low Emittance Lattice for PF-AR emittance, injection, cavity, operation 4148
 
  • N. Higashi, K. Harada, S. Nagahashi, N. Nakamura, T. Obina, R. Takai, H. Takaki
    KEK, Ibaraki, Japan
  • K. Hirano
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
 
  PF-AR is a synchrotron-type 6.5 GeV light source in KEK. The user-run was started in 1987, and the lattice is almost the same as the original one. Now we consider the emittance improvement to enlarge the horizontal tune advance in the normal cell. Thanks to this manipulation, the emittance will be improved to about a half of the current value.  
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THPMF053 Study of the Dynamic Aperture Reduction Due to Error Effects for the High Energy Photon Source sextupole, lattice, quadrupole, closed-orbit 4182
 
  • Z. Duan, D. Ji, Y. Jiao
    IHEP, Beijing, People's Republic of China
 
  Funding: Work supported by Natural Science Foundation of China(No.11605212).
The 6 GeV High Energy Photon Source (HEPS) employs a lattice of 48 hybrid 7BA cells, aims to achieve a natural emittance between 30 to 60 pm, within a circumference of about 1.3 km. In the performance evaluation of optimized lattices, we found that the dynamic aperture of the bare lat- tice were su cient for on-axis swap-out injection, but a large reduction in the dynamic aperture was observed in the simu- lation when including lattice imperfections and even after dedicated lattice corrections. In this paper, we identi ed the feed-down e ects of sextupoles as the major source of DA reduction, and proposed to use dedicated sextupole movers to e ciently reduce the orbit o sets in sextupoles, to par- tially recover the dynamic aperture, sextupole mover-based optics correction schemes were also discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF053  
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THPMF054 Beam Performance Simulation with Error Effects and Correction on HEPS Design multipole, sextupole, emittance, alignment 4186
 
  • D. Ji, X. Cui, Z. Duan, Y. Jiao, Y. Wei, Y.L. Zhao
    IHEP, Beijing, People's Republic of China
 
  The High Energy Photon Source (HEPS) is a 6-GeV, ul-tralow-emittance kilometre-scale storage ring light source to be built in China. In this paper, the progress of the error and correction effect study on HEPS over the past one year will be presented, including error requirement and correction progress update. And beam performance eval-uation with static error and correction on orbit, optics, emittance and dynamic aperture will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF054  
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THPMF072 Implementation of Ultra-Low Frequency Non-Linear Raman Spectroscopy with the Gun Laser at FLUTE experiment, scattering, laser, gun 4242
 
  • S. Funkner, E. Bründermann, A.-S. Müller, M.J. Nasse, G. Niehues, T. Schmelzer, J.L. Steinmann, M. Yan
    KIT, Eggenstein-Leopoldshafen, Germany
  • M. Tani
    University of Fukui, Fukui, Japan
 
  At the Karlsruhe Institute of Technology (KIT) the new compact versatile linear accelerator FLUTE is currently under commissioning. This accelerator will provide intense broadband THz pulses for spectroscopic experiments. Here, we demonstrate the implementation of a coherent Raman spectrometer using the RF gun laser of FLUTE. With our experiment, we can measure the Raman spectrum at ultra-low frequencies. The measurement principle, which was recently published, is based on coherent nonlinear excitation of the observed sample. The spectrometer consists of a stretcher and an interferometer, which can be simply built from standard optics. We will show that the accessible spectral range overlaps well with that from the THz pulses of the planned FLUTE experiment. Thus, the coherent Raman experiment can provide spectral information complementary to absorption spectral measurements using the THz radiation of FLUTE.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF072  
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THPMF077 A Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring lattice, emittance, focusing, sextupole 4252
 
  • S.C. Leemann, W.E. Byrne, M. Venturini
    LBNL, Berkeley, California, USA
  • J. Bengtsson
    DLS, Oxfordshire, United Kingdom
  • A. Streun
    PSI, Villigen PSI, Switzerland
 
  Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231
The current baseline for the ALS Upgrade to a diffraction-limited soft x-ray storage ring is a 9BA lattice with two dispersion bumps for localized chromatic corrections. Although this lattice meets the very aggressive emittance goal, it offers limited margins in terms of dynamic aperture and momentum acceptance. In this paper we explore a different approach based on a 7BA lattice with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance so that despite fewer bends an emittance comparable to the baseline lattice can be reached albeit with larger dynamic aperture and momentum acceptance. We present linear optics design, trade-offs between achievable emittance and longitudinal stability, as well as the employed nonlinear tuning approach and the resulting performance of this alternate lattice.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF077  
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THPMK071 Lattice Design for a 1.2 GeV Storage Ring emittance, dipole, lattice, storage-ring 4464
 
  • S.Q. Shen, S.Q. Tian, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
 
  It is a very effective way to bring down the emittance of storage ring by using the MBA lattice design. Based on this concept, some other solutions have been developed to reduce the emittance furthermore for recent years. In this paper, the lattice design for a 1.2 GeV storage ring will be presented. The solution of horizontal and longitudinal gradient bending magnets tried in this lattice is going to be discussed in detailed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK071  
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THPML074 Image Reconstruction Technique Based on Coded Aperture Imaging for SuperKEKB X-ray Beam Size Monitor detector, synchrotron, luminosity, electron 4819
 
  • E. Mulyani, J.W. Flanagan
    Sokendai, Ibaraki, Japan
  • J.W. Flanagan, H. Fukuma, H. Ikeda, M. Tobiyama
    KEK, Ibaraki, Japan
 
  The fast reconstruction techniques based on principles originally developed for coded aperture imaging have been investigated for SuperKEKB accelerator. The establishment of this technique will very important for measuring the beam sizes of all 2500 bunches in the SuperKEKB accelerator over thousands of turns, as needed for instability studies and luminosity tuning, due to the vast quantity of data that needs to be processed in a timely manner.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML074  
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THPML084 Validating the COBEA Algorithm at the DELTA Storage Ring storage-ring, betatron, closed-orbit, lattice 4851
 
  • B. Riemann, B.D. Isbarn, S. Khan, S. Koetter, T. Weis
    DELTA, Dortmund, Germany
 
  Closed-Orbit Bilinear-Exponential Analysis (COBEA) is an algorithm to decompose monitor-corrector response matrices into (scaled) beta optics values, phase advances, scaled dispersion and betatron tunes. No explicit magnetic lattice model is required for COBEA - only the sequence of monitors and correctors along the beam path (no lengths, no strengths approach). To obtain absolute beta values, the length of one drift space can be provided as optional input. In this work, the application of COBEA to the DELTA storage ring, operated by TU Dortmund University, is discussed, and its results for betatron tunes and scaled dispersion are compared with those of conventional, direct measurement methods. COBEA is also put in a historical perspective to other diagnostic algorithms. Improvements in the Python implementation of COBEA, which is available as free software, are presented. Due to COBEA being relatively modest regarding its requirements on input data respectively hardware, it should be applicable to the majority of existing storage rings.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML084  
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