Author: Stupakov, G.
Paper Title Page
S202
Cooling and Diffusion Rates in Coherent Electron Cooling Concepts  
 
  • S. Nagaitsev, V.A. Lebedev
    Fermilab, Batavia, Illinois, USA
  • W.F. Bergan, E. Wang
    BNL, Upton, New York, USA
  • G. Stupakov
    SLAC, Menlo Park, California, USA
 
  We present analytic cooling and diffusion rates for a simplified model of coherent electron cooling (CEC), based on a proton energy kick at each turn. This model also allows to estimate analytically the rms value of electron beam density fluctuations in the "kicker" section. Having such analytic expressions should allow for better understanding of the CEC mechanism, and for a quicker analysis and optimization of main system parameters. Our analysis is applicable to any CEC amplification mechanism, as long as the wake (kick) function is available.  
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S203
Microbunching Coherent Electron Cooling for the EIC Project  
 
  • G. Stupakov
    SLAC, Menlo Park, California, USA
 
  Reaching maximal luminosity for the planned electron-ion collider (EIC) calls for some form of strong hadron cooling to counteract beam emittance increase from IBS. The microbunched electron cooling (MBEC) is currently considered as a viable method for cooling hadrons in the collider. In this work we discuss the physics of the cooling and describe the mathematical models used in theoretical analysis and simulations to optimize of the cooling rate. We also place limits on the necessary electron beam quality. Some practical challenges of building the MBEC cooler will also be discussed.  
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S803 Wiggler Enhanced Plasma Amplifier for Coherent Electron Cooling 62
 
  • G. Stupakov
    SLAC, Menlo Park, California, USA
  • A. Zholents
    ANL, Lemont, Illinois, USA
 
  Funding: This work supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contracts No. DE-AC02- 06CH11357 and DE-AC02-76SF00515.
Coherent electron cooling* using a plasma-cascade amplifier (PCA) can provide about hundred thousand times faster cooling rates of hadrons than the conventional microwave stochastic cooling due to an extremely wide bandwidth of a pickup modulator, a kicker, and the amplifier. PCA proposed in ** creates unstable plasma oscillations using modulation of a plasma frequency by means of the modulation of the transverse beam size using strong field solenoids. Instead we propose to use modulation of the average longitudinal velocity of electrons replacing the solenoids by the wiggler magnets. This approach promises obtaining a more compact amplifier due a more efficient modulation of the plasma frequency, although it requires separation of the hadron and the electron orbits in the amplifier region.
* V. N. Litvinenko and Ya. S. Derbenev, Coherent Electron Cooling, PRL 102, 114801 (2009).
** V. N. Litvinenko et al., Plasma-cascade instability, Phys. Rev. Acc. and Beams, 24, 014402 (2021).
 
slides icon Slides S803 [3.645 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-S803  
About • paper received ※ 29 October 2021       paper accepted ※ 22 November 2021       issue date ※ 10 December 2021  
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P2009 A Perturbative Technique for 3D Modeling of the Microbunched Electron Cooling Concept 107
 
  • I.V. Pogorelov, D.L. Bruhwiler, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • G. Stupakov
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Award Number DE- SC0020592.
Because the efficacy of conventional electron cooling falls off rapidly with energy, reaching the cooling times at collision energy targeted by the Electron-Ion Collider (EIC) design can be challenging. A possible solution is offered by cooling schemes that are based on fundamentally different techniques such as microbunched electron cooling (MBEC). Regular PIC simulations of MBEC in the parameter regime of the EIC cooling system would require a prohibitively large number of particles to resolve the evolution of the ion-imprinted phase space density modulation. We explored a solution to this problem by developing and implementing in the code Warp an approach based on two perturbative techniques, the beam-frame delta-f method and a variant of the distribution difference (DD) technique. To model the dynamics of the ion-seeded modulation in the MBEC chicanes, we developed an approach that combines the DD and quiet start techniques with analysis of correlations between the divergence of DD trajectories and their location within the e-beam. We have also prototyped in Warp the computation of the time-dependent 3D wakefield in the MBEC kicker.
 
poster icon Poster P2009 [4.051 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-COOL2021-P2009  
About • paper received ※ 29 October 2021       paper accepted ※ 01 December 2021       issue date ※ 10 December 2021  
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