NAPAC2019 - List of Authors (Ma, J.)

Paper	Title	Page
MOZBB4	High Brightness CW Electron Beams From Superconducting RF Photoinjector
	I. Petrushina SUNY SB, Stony Brook, New York, USA T. Hayes, Y.C. Jing, V. Litvinenko, J. Ma, G. Narayan, I. Pinayev, F. Severino, K.S. Smith, G. Wang BNL, Upton, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA K. Shih SBU, Stony Brook, New York, USA
	The next generation electron beam facilities, such as high-power free electron lasers (FELs), energy-recovery linacs, or coolers for hadron beams, raise the strict requirements on the quality of the electron beam. Fortunately, the superconducting RF (SRF) technology is well suited for generating CW electron beams in high accelerating gradient environments. Recent achievements in the SRF photoinjector realm demonstrated the ability of the modern SRF guns to provide stable operation with high-brightness beams. In this paper, we report the excellent performance of our SRF gun with CsK2Sb photocathode that was built for the Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment at RHIC. The gun is generating high charge electron bunches (up to 10 nC per bunch) and low transverse emittances with the cathodes operating for months without significant loss of quantum efficiency. We will provide a brief overview of the main stages of the commissioning of our gun along with a detailed discussion of the main challenges during the operation. This is followed by the description of the emittance studies, including our experimental results and numerical simulations.
	Slides MOZBB4 [10.537 MB]
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TUZBA1	Commissioning of the Electron Accelerator LEReC for Bunched Beam Cooling	330
	D. Kayran, Z. Altinbas, D. Bruno, M.R. Costanzo, K.A. Drees, A.V. Fedotov, W. Fischer, M. Gaowei, D.M. Gassner, X. Gu, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, J. Kewisch, C.J. Liaw, C. Liu, J. Ma, K. Mernick, T.A. Miller, M.G. Minty, L.K. Nguyen, M.C. Paniccia, I. Pinayev, V. Ptitsyn, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, A. Sukhanov, P. Thieberger, J.E. Tuozzolo, E. Wang, G. Wang, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The brand-new state of the art electron accelerator, LEReC, was built and commissioned at BNL. LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. Electron beam quality suitable for cooling in the Relativistic Heavy Ion Collider (RHIC) was achieved [1], which lead to the first demonstration of bunched beam electron cooling of hadron beams [2]. This presentation will discuss commissioning results, achieved beam parameters and performance of the LEReC systems. [1] D.Kayran et al., First results from Commissioning of LEReC, in Proc of IPAC2019 [2] A.Fedotov et al., First electron cooling of hadron beams using a bunched electron beam, presented at NAPAC2019
	Slides TUZBA1 [18.343 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBA1
About •	paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
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TUPLM07	First Experimental Observations of the Plasma-Cascade Instability in the CeC PoP Accelerator	379
TUPLM04	use link to see paper's listing under its alternate paper code
	I. Petrushina SUNY SB, Stony Brook, New York, USA Y.C. Jing, V. Litvinenko, J. Ma, I. Pinayev, G. Wang, Y.H. Wu BNL, Upton, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA K. Shih SBU, Stony Brook, New York, USA
	Preservation of the beam quality is important for attaining the desirable properties of the beam. Collective effects can produce an instability severely degrading beam emittance, momentum spread and creating filamentation of the beam. Microbunching instability for beams traveling along a curved trajectory, and space charge driven parametric transverse instabilities are well-known and in-depth studied. However, none of the above include a microbunching longitudinal instability driven by modulations of the transverse beam size. This phenomenon was observed for the first time during the commissioning of the CeC PoP experiment. Based on the dynamics of this instability we named it a Plasma-Cascade Instability (PCI). PCI can strongly intensify longitudinal micro-bunching originating from the beam’s shot noise, and even saturate it. Resulting random density and energy microstructures in the beam can become a serious problem for generating high quality electron beams. On the other hand, such instability can drive novel high-power sources of broadband radiation. In this paper we present our experimental observations of the PCI and the supporting results of the numerical simulations.
	Poster TUPLM07 [17.319 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM07
About •	paper received ※ 27 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
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TUPLH24	Performance of CeC PoP Accelerator	526
	I. Pinayev, Z. Altinbas, J.C. Brutus, A.J. Curcio, A. Di Lieto, T. Hayes, R.L. Hulsart, P. Inacker, Y.C. Jing, V. Litvinenko, J. Ma, G.J. Mahler, M. Mapes, K. Mernick, K. Mihara, T.A. Miller, M.G. Minty, G. Narayan, I. Petrushina, F. Severino, K. Shih, Z. Sorrell, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman BNL, Upton, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Coherent electron cooling experiment is aimed for demonstration of the proof-of-principle demonstration of reduction energy spread of a single hadron bunch circulating in RHIC. The electron beam should have the required parameters and its orbit and energy should be matched to the hadron beam. In this paper we present the achieved electron beam parameters including emittance, energy spread, and other critical indicators. The operational issues as well as future plans are also discussed.
	Poster TUPLH24 [11.180 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH24
About •	paper received ※ 29 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THZBA5	First Electron Cooling of Hadron Beams Using a Bunched Electron Beam	957
	A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao BNL, Upton, New York, USA
	Funding: Work supported by the U.S. Department of Energy. The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.
	Slides THZBA5 [16.417 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5
About •	paper received ※ 16 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOZBB4

High Brightness CW Electron Beams From Superconducting RF Photoinjector

I. Petrushina
SUNY SB, Stony Brook, New York, USA
T. Hayes, Y.C. Jing, V. Litvinenko, J. Ma, G. Narayan, I. Pinayev, F. Severino, K.S. Smith, G. Wang
BNL, Upton, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA
K. Shih
SBU, Stony Brook, New York, USA

The next generation electron beam facilities, such as high-power free electron lasers (FELs), energy-recovery linacs, or coolers for hadron beams, raise the strict requirements on the quality of the electron beam. Fortunately, the superconducting RF (SRF) technology is well suited for generating CW electron beams in high accelerating gradient environments. Recent achievements in the SRF photoinjector realm demonstrated the ability of the modern SRF guns to provide stable operation with high-brightness beams. In this paper, we report the excellent performance of our SRF gun with CsK2Sb photocathode that was built for the Coherent electron Cooling (CeC) Proof of Principle (PoP) experiment at RHIC. The gun is generating high charge electron bunches (up to 10 nC per bunch) and low transverse emittances with the cathodes operating for months without significant loss of quantum efficiency. We will provide a brief overview of the main stages of the commissioning of our gun along with a detailed discussion of the main challenges during the operation. This is followed by the description of the emittance studies, including our experimental results and numerical simulations.

Slides MOZBB4 [10.537 MB]

Export •

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

TUZBA1

Commissioning of the Electron Accelerator LEReC for Bunched Beam Cooling

330

D. Kayran, Z. Altinbas, D. Bruno, M.R. Costanzo, K.A. Drees, A.V. Fedotov, W. Fischer, M. Gaowei, D.M. Gassner, X. Gu, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, J. Kewisch, C.J. Liaw, C. Liu, J. Ma, K. Mernick, T.A. Miller, M.G. Minty, L.K. Nguyen, M.C. Paniccia, I. Pinayev, V. Ptitsyn, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, A. Sukhanov, P. Thieberger, J.E. Tuozzolo, E. Wang, G. Wang, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The brand-new state of the art electron accelerator, LEReC, was built and commissioned at BNL. LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. Electron beam quality suitable for cooling in the Relativistic Heavy Ion Collider (RHIC) was achieved [1], which lead to the first demonstration of bunched beam electron cooling of hadron beams [2]. This presentation will discuss commissioning results, achieved beam parameters and performance of the LEReC systems.
[1] D.Kayran et al., First results from Commissioning of LEReC, in Proc of IPAC2019
[2] A.Fedotov et al., First electron cooling of hadron beams using a bunched electron beam, presented at NAPAC2019

Slides TUZBA1 [18.343 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUZBA1

About •

paper received ※ 27 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

Export •

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

TUPLM07

First Experimental Observations of the Plasma-Cascade Instability in the CeC PoP Accelerator

379

TUPLM04

use link to see paper's listing under its alternate paper code

I. Petrushina
SUNY SB, Stony Brook, New York, USA
Y.C. Jing, V. Litvinenko, J. Ma, I. Pinayev, G. Wang, Y.H. Wu
BNL, Upton, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA
K. Shih
SBU, Stony Brook, New York, USA

Preservation of the beam quality is important for attaining the desirable properties of the beam. Collective effects can produce an instability severely degrading beam emittance, momentum spread and creating filamentation of the beam. Microbunching instability for beams traveling along a curved trajectory, and space charge driven parametric transverse instabilities are well-known and in-depth studied. However, none of the above include a microbunching longitudinal instability driven by modulations of the transverse beam size. This phenomenon was observed for the first time during the commissioning of the CeC PoP experiment. Based on the dynamics of this instability we named it a Plasma-Cascade Instability (PCI). PCI can strongly intensify longitudinal micro-bunching originating from the beam’s shot noise, and even saturate it. Resulting random density and energy microstructures in the beam can become a serious problem for generating high quality electron beams. On the other hand, such instability can drive novel high-power sources of broadband radiation. In this paper we present our experimental observations of the PCI and the supporting results of the numerical simulations.

Poster TUPLM07 [17.319 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLM07

About •

paper received ※ 27 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

Export •

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

TUPLH24

Performance of CeC PoP Accelerator

526

I. Pinayev, Z. Altinbas, J.C. Brutus, A.J. Curcio, A. Di Lieto, T. Hayes, R.L. Hulsart, P. Inacker, Y.C. Jing, V. Litvinenko, J. Ma, G.J. Mahler, M. Mapes, K. Mernick, K. Mihara, T.A. Miller, M.G. Minty, G. Narayan, I. Petrushina, F. Severino, K. Shih, Z. Sorrell, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman
BNL, Upton, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Coherent electron cooling experiment is aimed for demonstration of the proof-of-principle demonstration of reduction energy spread of a single hadron bunch circulating in RHIC. The electron beam should have the required parameters and its orbit and energy should be matched to the hadron beam. In this paper we present the achieved electron beam parameters including emittance, energy spread, and other critical indicators. The operational issues as well as future plans are also discussed.

Poster TUPLH24 [11.180 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLH24

About •

paper received ※ 29 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

Export •

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

THZBA5

First Electron Cooling of Hadron Beams Using a Bunched Electron Beam

957

A.V. Fedotov, Z. Altinbas, M. Blaskiewicz, J.M. Brennan, D. Bruno, J.C. Brutus, M.R. Costanzo, K.A. Drees, W. Fischer, J.M. Fite, M. Gaowei, D.M. Gassner, X. Gu, J. Halinski, K. Hamdi, L.R. Hammons, T. Hayes, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, P.K. Kankiya, D. Kayran, J. Kewisch, D. Lehn, C.J. Liaw, C. Liu, J. Ma, G.J. Mahler, M. Mapes, A. Marusic, K. Mernick, C. Mi, R.J. Michnoff, T.A. Miller, M.G. Minty, S.K. Nayak, L.K. Nguyen, M.C. Paniccia, I. Pinayev, S. Polizzo, V. Ptitsyn, T. Rao, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, H. Song, A. Sukhanov, R. Than, P. Thieberger, S.M. Trabocchi, J.E. Tuozzolo, P. Wanderer, E. Wang, G. Wang, D. Weiss, B.P. Xiao, T. Xin, W. Xu, A. Zaltsman, H. Zhao, Z. Zhao
BNL, Upton, New York, USA

Funding: Work supported by the U.S. Department of Energy.
The Low Energy RHIC electron Cooler (LEReC) was recently constructed and commissioned at BNL. The LEReC is the first electron cooler based on the RF acceleration of electron bunches (previous electron coolers all used DC beams). Bunched electron beams are necessary for cooling hadron beams at high energies. The challenges of such an approach include generation of electron beams suitable for cooling, delivery of electron beams of the required quality to the cooling sections without degradation of beam emittances and energy spread, achieving required small angles between electrons and ions in the cooling sections, precise energy matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched beam cooling. Following successful commissioning of the electron accelerator in 2018, the focus of the LEReC project in 2019 was on establishing electron-ion interactions and demonstration of cooling process using electron energy of 1.6MeV (ion energy of 3.85GeV/n), which is the lowest energy of interest. Here we report on the first demonstration of Au ion cooling in RHIC using this new approach.

Slides THZBA5 [16.417 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-THZBA5

About •

paper received ※ 16 August 2019 paper accepted ※ 31 August 2019 issue date ※ 08 October 2019

Export •

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