05 Beam Dynamics and EM Fields
D10 Beam-Beam Effects - Theory, Simulations, Measurements, Code Developments
Paper Title Page
TUPMK016 Using Time Evolution of the Bunch Structure to Extract the Muon Momentum Distribution in the Fermilab Muon g-2 Experiment 1526
 
  • W. Wu, B. Quinn
    UMiss, University, Mississippi, USA
  • J.D. Crnkovic
    BNL, Upton, Long Island, New York, USA
 
  Beam dynamics plays an important role in achieving the unprecedented precision on measurement of the muon anomalous magnetic moment in the Fermilab Muon g-2 Experiment. It needs to find the muon momentum distribution in the storage ring in order to evaluate the electric field correction to muon anomalous precession frequency. We will show how to use time evolution of the beam bunch structure to extract the muon momentum distribution by applying a fast rotation analysis on the decay electron signals.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMK016  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEYGBE3
New Features of Beamstruhlung Important for Crab-Waist e+e Colliders  
 
  • V.I. Telnov
    BINP SB RAS, Novosibirsk, Russia
 
  It is already known that beamstrahlung put a limitation on attainable luminosity of circular high energy e+e colliders (like FCC-ee and CEPC), it determines beam lifetimes, increase the energy spread and leads to a beam lengthening. Current projects take these effects into account using well known synchrotron radiation (SR) formulas. In this talk I show that these formulas are not applicable for colliders with crab-waist collisions (all new projects of circular e+e colliders) because at these colliders the deflection angle during the beam collisions θ< 1/γ. In this case the characteristic maximum frequency is ωm ≈cγ2/σ instead of the SR critical frequency ωc≈cγ3/ρ (where σ is the crossing length), the ratio ωmc >1 and the spectrum is completely different. As result all effects due to beamstrahlung are stronger than give standard SR formulas. In the talk results of exact numerical calculation of beamstrahlung spectra for parameter region of e+e circular collides are presented with analysis and conclusion.  
slides icon Slides WEYGBE3 [2.287 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAF005 Simulations of Modulator for Coherent Electron Cooling 2953
 
  • J. Ma, V. Litvinenko, G. Wang
    BNL, Upton, Long Island, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Highly resolved numerical simulations have been performed using the code SPACE for the modulator, the first section of the Coherent electron cooling (CeC) device installed in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Simulation results have been benchmarked with analytical solution using uniform electron beam with realistic thermal velocities. Electron bunches with Gaussian distribution and quadrupole field with realistic settings have been applied in the simulations to predict the modulation process and final bunching factors induced by ions with reference and off-reference energies in the CeC experiment at BNL RHIC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF005  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAF006 Simulations of Cooling Rate and Diffusion for Coherent Electron Cooling Experiment 2957
 
  • J. Ma, V. Litvinenko, G. Wang
    BNL, Upton, Long Island, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Start-to-end numerical simulations have been performed using the code SPACE and GENESIS for the single pass of gold ions through the coherent electron cooling (CeC) device installed in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Cooling rate of CeC experiment has been predicted using off-reference energy ions in a finite Gaussian electron beam through a realistic beam-line, in which settings of quadrupoles and free-electron laser (FEL) device are relevant to BNL RHIC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF006  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAF074 Landau Damping Studies for the FCC: Octupole Magnets, Electron Lens and Beam-Beam Effects 3150
 
  • C. Tambasco, J. Barranco García, T. Pieloni, L. Rivkin
    EPFL, Lausanne, Switzerland
  • S. Arsenyev, X. Buffat, D. Schulte
    CERN, Geneva, Switzerland
 
  Funding: This work is supported by the Swiss State Secretariat for Education, Research and Innovation SERI.
Stability studies for the FCC-hh operational cycle are explored using Landau octupoles and electron lenses alone and in the presence of long-range as well as head-on beam-beam effects. Pros and cons of the various methods are compared and an optimum operational scenario to guarantee the maximum stability is proposed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF074  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAK108 Fourier Coefficients of Long-Range Beam-Beam Hamiltonian via Two-Dimensional Bessel functions 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  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAK131 Investigation of Two-Bunch Train Compression by Velocity Bunching 3548
 
  • D. Wang, Y. C. Du, W.-H. Huang, X. Liu, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan
    TUB, Beijing, People's Republic of China
  • H. Zhang
    Tsinghua University, Beijing, People's Republic of China
 
  Two electron beamlets, also referred as two-bunch train with adjustable time and energy spacing are popular in many applications such as two color FEL and pump-probe experiments. We investigate compression of two-bunch train via velocity bunching scheme in a traveling wave accelerator (TWA) tube by varying the phase of TWA tube in a very large range. Beam dynamics simulations show that when the phase injected into the accelerator tube for the beam is set to ≪-100 degree, velocity bunching occurs in a deep over-compression mode, where two-bunch train is continuously tunable in time and in energy space, and the emittance of each sub-bunch is also preserved. In the experiment, we use energy spectrum and defecting cavity to diagnose the train's energy space and time space respectively, the measurements demonstrated that two-bunch train through deep over-compression scheme is separated both in time and in energy space, which also agree well with the predictions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK131  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAL157 Investigation of Transverse Wakefield and Beam Break Up Effect in Irradiation Linacs 4020
 
  • X.C. Meng, H.B. Chen, J. Shi, Z.H. Wang, H. Zha, S.X. Zheng
    TUB, Beijing, People's Republic of China
  • G.H. Li, J.S. Liu, Y.H. Liu
    NUCTECH, Beijing, People's Republic of China
 
  Study of beam break up effect in linacs has been done in recent years. The beam-induced high order dipolar modes, especially the TM11-like mode were investigated for the linacs both in travelling wave and backward trav-elling wave. Measurements of beam-break up in a travel-ling wave linac were carried out and results are discussed. Moreover, a theoretical model was developed for the irradiation linacs to study the detailed interaction be-tween the transverse wakefield and the electron beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL157  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)