IPAC2021 - List of Authors (Stupakov, G.)

Paper	Title	Page
TUPAB179	Design of an MBEC Cooler for the EIC	1819
	W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang BNL, Upton, New York, USA G. Stupakov SLAC, Menlo Park, California, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. 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. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.
	Poster TUPAB179 [4.006 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179
About •	paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021
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TUPAB264	Shielding of CSR Wake in a Drift	2079
	G. Stupakov SLAC, Menlo Park, California, USA
	Funding: Work supported by the Department of Energy, contract DE-AC03-76SF00515. A one-dimensional model of coherent synchrotron radiation (CSR) wakefield developed in Refs. [,] is used in computer codes for the simulation of relativistic electron beams. It includes transient effects at the entrance and exit from a bending magnet of finite length. In the ultra-relativistic limit, v=c, the exit CSR wake decays inversely proportional to the distance from the magnet end. To calculate the total energy loss of the beam one needs to integrate this wake to infinity, but the integral diverges. This means that one has to either drop the assumption of the infinite value of the Lorentz factor or take into account the shielding effect of the metal walls in the vacuum chamber. In practice, the latter effect is often dominant. In this work, we derive formulas for the CSR wake in the drift after an exit from the magnet that incorporates the shielding by two parallel metal plates. They allow computing the energy loss of different particles in the beam. E. L. Saldin, E. A. Schneidmiller, and M. V. Yurkov. NIMA v. 398, p. 373 (1997). ** G. Stupakov and P. Emma. In: Proceedings of 8th EPAC. Paris, France, 2002, p. 1479.
	Poster TUPAB264 [0.661 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB264
About •	paper received ※ 10 May 2021 paper accepted ※ 25 June 2021 issue date ※ 22 August 2021
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WEPAB005	Design Status Update of the Electron-Ion Collider	2585
	C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, New York, USA S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan SLAC, Menlo Park, California, USA K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA T. Satogata ODU, Norfolk, Virginia, USA D. Xu FRIB, East Lansing, Michigan, USA
	Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy. The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.
	Poster WEPAB005 [2.095 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005
About •	paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021
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WEPAB273	Cooling and Diffusion Rates in Coherent Electron Cooling Concepts	3281
	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
	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. 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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB273
About •	paper received ※ 10 May 2021 paper accepted ※ 28 July 2021 issue date ※ 29 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXA05	A Fast Method of 2D Calculation of Coherent Synchrotron Radiation Wakefield in Relativistic Beams	3696
	J. Tang, Z. Huang, G. Stupakov SLAC, Menlo Park, California, USA
	Coherent Synchrotron Radiation (CSR) is regarded as one of the most important reasons that limit beam brightness in modern accelerators. CSR wakefield is often computed in a 1D assuming a line charge, which can become invalid when the beam has a large transverse extension and small bunch length. On the other hand, the existing 2D or 3D codes are often computationally inefficient or incomplete. In our previous work * we developed a new model for fast computation of 2D CSR wakefield in relativistic beams with Gaussian distribution. Here we further generalize this model to achieve self-consistent computation compatible with arbitrary beam distribution and nonlinear magnetic lattice with particle tracking. These new features can enable us to perform realistic simulations and study the physics of CSR beyond 1D in electron beams with extreme short bunch length and high peak current. * J. Tang and G. Stupakov. NAPAC2019, paper WEPLS09 (2019).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA05
About •	paper received ※ 19 May 2021 paper accepted ※ 20 July 2021 issue date ※ 21 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design of an MBEC Cooler for the EIC

1819

W.F. Bergan, P. Baxevanis, M. Blaskiewicz, E. Wang
BNL, Upton, New York, USA
G. Stupakov
SLAC, Menlo Park, California, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
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. We discuss plans to use microbunched electron cooling (MBEC) to achieve this. The principle of this method is that the hadron beam will copropogate with a beam of electrons, imprinting its own density modulation on the electron beam. These electron phase space perturbations are amplified before copropogating with the hadrons again in a kicker section. By making the hadron transit time between modulator and kicker dependent on hadron energy and transverse offset, the energy kicks which they receive from the electrons will tend to reduce their longitudinal and transverse emittances. We discuss details of the analytic theory and searches for optimal realistic parameter settings to achieve a maximal cooling rate while limiting the effects of diffusion and electron beam saturation. We also place limits on the necessary electron beam quality. These results are corroborated by simulations.

Poster TUPAB179 [4.006 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB179

About •

paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 24 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB264

Shielding of CSR Wake in a Drift

2079

G. Stupakov
SLAC, Menlo Park, California, USA

Funding: Work supported by the Department of Energy, contract DE-AC03-76SF00515.
A one-dimensional model of coherent synchrotron radiation (CSR) wakefield developed in Refs. [*,**] is used in computer codes for the simulation of relativistic electron beams. It includes transient effects at the entrance and exit from a bending magnet of finite length. In the ultra-relativistic limit, v=c, the exit CSR wake decays inversely proportional to the distance from the magnet end. To calculate the total energy loss of the beam one needs to integrate this wake to infinity, but the integral diverges. This means that one has to either drop the assumption of the infinite value of the Lorentz factor or take into account the shielding effect of the metal walls in the vacuum chamber. In practice, the latter effect is often dominant. In this work, we derive formulas for the CSR wake in the drift after an exit from the magnet that incorporates the shielding by two parallel metal plates. They allow computing the energy loss of different particles in the beam.
* E. L. Saldin, E. A. Schneidmiller, and M. V. Yurkov. NIMA v. 398, p. 373 (1997).
** G. Stupakov and P. Emma. In: Proceedings of 8th EPAC. Paris, France, 2002, p. 1479.

Poster TUPAB264 [0.661 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB264

About •

paper received ※ 10 May 2021 paper accepted ※ 25 June 2021 issue date ※ 22 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB005

Design Status Update of the Electron-Ion Collider

2585

C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, New York, USA
S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan
SLAC, Menlo Park, California, USA
K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
T. Satogata
ODU, Norfolk, Virginia, USA
D. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy.
The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.

Poster WEPAB005 [2.095 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005

About •

paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB273

Cooling and Diffusion Rates in Coherent Electron Cooling Concepts

3281

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

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.
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.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB273

About •

paper received ※ 10 May 2021 paper accepted ※ 28 July 2021 issue date ※ 29 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THXA05

A Fast Method of 2D Calculation of Coherent Synchrotron Radiation Wakefield in Relativistic Beams

3696

J. Tang, Z. Huang, G. Stupakov
SLAC, Menlo Park, California, USA

Coherent Synchrotron Radiation (CSR) is regarded as one of the most important reasons that limit beam brightness in modern accelerators. CSR wakefield is often computed in a 1D assuming a line charge, which can become invalid when the beam has a large transverse extension and small bunch length. On the other hand, the existing 2D or 3D codes are often computationally inefficient or incomplete. In our previous work * we developed a new model for fast computation of 2D CSR wakefield in relativistic beams with Gaussian distribution. Here we further generalize this model to achieve self-consistent computation compatible with arbitrary beam distribution and nonlinear magnetic lattice with particle tracking. These new features can enable us to perform realistic simulations and study the physics of CSR beyond 1D in electron beams with extreme short bunch length and high peak current.
* J. Tang and G. Stupakov. NAPAC2019, paper WEPLS09 (2019).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXA05

About •

paper received ※ 19 May 2021 paper accepted ※ 20 July 2021 issue date ※ 21 August 2021

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)