IPAC2016 - List of Authors (Wang, G.)

Paper	Title	Page
TUPMR008	Simulation of Ion Beam under Coherent Electron Cooling	1243
	G. Wang, M. Blaskiewicz, V. Litvinenko BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The proof of coherent electron cooling (CeC) principle experiment is currently under commissioning and it is essential to have the tools to predict the influences of cooling electrons on a circulating ion bunch. Recently, we have developed a simulation code to track the evolution of an ion bunch under the influences of both CeC and Intra-beam scattering (IBS). In this paper, we will first show the results of benchmarking the code with numerical solutions of Fokker-Planck equation and then present the simulation results for the proof of CeC principle experiment.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR008
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TUPMR009	Analytical Studies of Ion Beam Evolution under Coherent Electron Cooling	1247
	G. Wang, M. Blaskiewicz, V. Litvinenko BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In the presence of coherent electron cooling (CeC), the evolution of the longitudinal profile of a circulating ion bunch can be described by the 1-D Fokker-Planck equation. We show that, in the absence of diffusion, the 1-D equation can be solved analytically for certain dependence of cooling force on the synchrotron amplitude. For more general cases, we solved the 1-D Fokker-Planck equation numerically and the numerical solutions have been used to benchmark our simulation code as well as providing fast estimations of the cooling effects.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR009
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TUPMW038	RHIC Operation with Asymmetric Collisions in 2015	1527
	C. Liu, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, J.S. Laster, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, G. Narayan, S.K. Nayak, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, G. Wang, K. Yip, A. Zaltsman, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA S.M. White ESRF, Grenoble, France
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Collisions with beams of highly asymmetric rigidities (proton-Gold and proton-Aluminum) were provided for the RHIC physics programs in 2015. Magnets were moved for the first time in RHIC prior to the run to accommodate the asymmetric beam trajectories during acceleration and at store. A special ramping scheme was designed to keep the revolution frequencies of the beams in the two rings equal. The unique operational experience of the asymmetric run will be reviewed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW038
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WEZA01	RHIC Performance with Stochastic Cooling for Ions and Head-on Beam-beam Compensation for Protons	2055
	W. Fischer, J.G. Alessi, Z. Altinbas, E.C. Aschenauer, G. Atoian, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, M.R. Costanzo, T. D'Ottavio, K.A. Drees, A.V. Fedotov, C.J. Gardner, D.M. Gassner, X. Gu, C.E. Harper, M. Harvey, T. Hayes, J. Hock, H. Huang, R.L. Hulsart, J.P. Jamilkowski, T. Kanesue, N.A. Kling, J.S. Laster, C. Liu, Y. Luo, D. Maffei, Y. Makdisi, M. Mapes, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, J. Morris, G. Narayan, C. Naylor, S. Nemesure, M. Okamura, S. Perez, A.I. Pikin, P.H. Pile, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, R. Than, P. Thieberger, J.E. Tuozzolo, B. Van Kuik, G. Wang, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, W. Zhang BNL, Upton, Long Island, New York, USA M. Bai, Y. Dutheil FZJ, Jülich, Germany S.M. White ESRF, Grenoble, France
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The Relativistic Heavy Ion Collider (RHIC) has two main operating modes with heavy ions and polarized protons respectively. In addition to a continuous increase in the bunch intensity in all modes, two major new systems were completed recently mitigating the main luminosity limit and leading to significant performance improvements. For heavy ion operation stochastic cooling mitigates the effects of intrabeam scattering, and for polarized proton operation head-on beam-beam compensation mitigated the beam-beam effect. We present the performance increases with these upgrades for heavy ions and polarized protons, as well as an overview of all operating modes past and planned.
	Slides WEZA01 [12.687 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEZA01
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WEOAB02	Record Performance of SRF Gun with CsK2Sb Photocathode	2085
	I. Pinayev, Z. Altinbas, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, A.J. Curcio, A. Di Lieto, C. Folz, D.M. Gassner, M. Harvey, T. Hayes, R.L. Hulsart, J.P. Jamilkowski, Y.C. Jing, D. Kayran, R. Kellermann, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, K. Mernick, R.J. Michnoff, T.A. Miller, M.G. Minty, G. Narayan, P. Orfin, D. Phillips, T. Rao, J. Reich, T. Roser, B. Sheehy, J. Skaritka, L. Smart, K.S. Smith, L. Snydstrup, V. Soria, Z. Sorrell, R. Than, C. Theisen, J.E. Tuozzolo, E. Wang, G. Wang, B. P. Xiao, T. Xin, W. Xu, A. Zaltsman, Z. Zhao BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. High-gradient CW photo-injectors operating at high ac-celerating gradients promise to revolutionize many sci-ences and applications. They can establish the basis for super-bright monochromatic X-ray and gamma-ray sources, high luminosity hadron colliders, nuclear- waste transmutation or a new generation of microchip produc-tion. In this paper we report on our operation of a super-conducting RF electron gun with a record-high accelerat-ing gradient at the CsK2Sb photocathode (i.e. ~ 20 MV/m) generating a record-high bunch charge (i.e., 2 nC). We briefly describe the system and then detail our experimental results.
	Slides WEOAB02 [28.500 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAB02
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WEPMW027	The ERL-based Design of Electron-Hadron Collider eRHIC	2482
	V. Ptitsyn, E.C. Aschenauer, I. Ben-Zvi, J.S. Berg, M. Blaskiewicz, S.J. Brooks, K.A. Brown, J.C. Brutus, O.V. Chubar, A.V. Fedotov, D.M. Gassner, H. Hahn, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, Y.C. Jing, R.F. Lambiase, V. Litvinenko, C. Liu, Y. Luo, G.J. Mahler, B. Martin, G.T. McIntyre, W. Meng, F. Méot, T.A. Miller, M.G. Minty, B. Parker, I. Pinayev, V.H. Ranjbar, T. Roser, J. Skaritka, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, E. Wang, G. Wang, H. Witte, Q. Wu, C. Xu, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Recent developments of the ERL-based design of future high luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (L ~ 10³³ cm^-2 s^-1) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design (L > 10³⁴ cm^-2 s^-1) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW027
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THPOY048	NSLS-II Active Interlock System and Post-Mortem Architecture	4214
	K. Ha, E.B. Blum, W.X. Cheng, J. Choi, Y. Hu, D. Padrazo, S. Seletskiy, O. Singh, R.M. Smith, J. Tagger, Y. Tian, G. Wang, T. Yang BNL, Upton, Long Island, New York, USA
	The NSLS-II at Brookhaven National Laboratory (BNL) started the user beam service in early 2015, and is currently operating 13 of the insertion device (ID) and beamlines as well as constructing new beamlines. The fast machine protection consists of an active interlock system (AIS), beam position monitor (BPM), cell controller (CCs) and front-end (FE) systems. The AIS measures the electron beam envelop and the dumps the beam by turning off RF system, and then the diagnostic system provides the post-mortem data for an analysis of which system caused the beam dump and the machine status analysis. NSLS-II post-mortem system involves AIS, CCs, BPMs, radio frequency system (RFs), power supply systems (PSs) as well as the timing system. This paper describes the AIS architecture and PM performance for NSLS-II safe operations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY048
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Paper

Title

Page

Simulation of Ion Beam under Coherent Electron Cooling

1243

G. Wang, M. Blaskiewicz, V. Litvinenko
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The proof of coherent electron cooling (CeC) principle experiment is currently under commissioning and it is essential to have the tools to predict the influences of cooling electrons on a circulating ion bunch. Recently, we have developed a simulation code to track the evolution of an ion bunch under the influences of both CeC and Intra-beam scattering (IBS). In this paper, we will first show the results of benchmarking the code with numerical solutions of Fokker-Planck equation and then present the simulation results for the proof of CeC principle experiment.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR008

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TUPMR009

Analytical Studies of Ion Beam Evolution under Coherent Electron Cooling

1247

G. Wang, M. Blaskiewicz, V. Litvinenko
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In the presence of coherent electron cooling (CeC), the evolution of the longitudinal profile of a circulating ion bunch can be described by the 1-D Fokker-Planck equation. We show that, in the absence of diffusion, the 1-D equation can be solved analytically for certain dependence of cooling force on the synchrotron amplitude. For more general cases, we solved the 1-D Fokker-Planck equation numerically and the numerical solutions have been used to benchmark our simulation code as well as providing fast estimations of the cooling effects.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR009

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TUPMW038

RHIC Operation with Asymmetric Collisions in 2015

1527

C. Liu, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, J.S. Laster, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, G. Narayan, S.K. Nayak, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, G. Wang, K. Yip, A. Zaltsman, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA
S.M. White
ESRF, Grenoble, France

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Collisions with beams of highly asymmetric rigidities (proton-Gold and proton-Aluminum) were provided for the RHIC physics programs in 2015. Magnets were moved for the first time in RHIC prior to the run to accommodate the asymmetric beam trajectories during acceleration and at store. A special ramping scheme was designed to keep the revolution frequencies of the beams in the two rings equal. The unique operational experience of the asymmetric run will be reviewed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW038

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WEZA01

RHIC Performance with Stochastic Cooling for Ions and Head-on Beam-beam Compensation for Protons

2055

W. Fischer, J.G. Alessi, Z. Altinbas, E.C. Aschenauer, G. Atoian, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, M.R. Costanzo, T. D'Ottavio, K.A. Drees, A.V. Fedotov, C.J. Gardner, D.M. Gassner, X. Gu, C.E. Harper, M. Harvey, T. Hayes, J. Hock, H. Huang, R.L. Hulsart, J.P. Jamilkowski, T. Kanesue, N.A. Kling, J.S. Laster, C. Liu, Y. Luo, D. Maffei, Y. Makdisi, M. Mapes, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, J. Morris, G. Narayan, C. Naylor, S. Nemesure, M. Okamura, S. Perez, A.I. Pikin, P.H. Pile, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, R. Than, P. Thieberger, J.E. Tuozzolo, B. Van Kuik, G. Wang, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, W. Zhang
BNL, Upton, Long Island, New York, USA
M. Bai, Y. Dutheil
FZJ, Jülich, Germany
S.M. White
ESRF, Grenoble, France

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The Relativistic Heavy Ion Collider (RHIC) has two main operating modes with heavy ions and polarized protons respectively. In addition to a continuous increase in the bunch intensity in all modes, two major new systems were completed recently mitigating the main luminosity limit and leading to significant performance improvements. For heavy ion operation stochastic cooling mitigates the effects of intrabeam scattering, and for polarized proton operation head-on beam-beam compensation mitigated the beam-beam effect. We present the performance increases with these upgrades for heavy ions and polarized protons, as well as an overview of all operating modes past and planned.

Slides WEZA01 [12.687 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEZA01

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WEOAB02

Record Performance of SRF Gun with CsK2Sb Photocathode

2085

I. Pinayev, Z. Altinbas, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, A.J. Curcio, A. Di Lieto, C. Folz, D.M. Gassner, M. Harvey, T. Hayes, R.L. Hulsart, J.P. Jamilkowski, Y.C. Jing, D. Kayran, R. Kellermann, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, K. Mernick, R.J. Michnoff, T.A. Miller, M.G. Minty, G. Narayan, P. Orfin, D. Phillips, T. Rao, J. Reich, T. Roser, B. Sheehy, J. Skaritka, L. Smart, K.S. Smith, L. Snydstrup, V. Soria, Z. Sorrell, R. Than, C. Theisen, J.E. Tuozzolo, E. Wang, G. Wang, B. P. Xiao, T. Xin, W. Xu, A. Zaltsman, Z. Zhao
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
High-gradient CW photo-injectors operating at high ac-celerating gradients promise to revolutionize many sci-ences and applications. They can establish the basis for super-bright monochromatic X-ray and gamma-ray sources, high luminosity hadron colliders, nuclear- waste transmutation or a new generation of microchip produc-tion. In this paper we report on our operation of a super-conducting RF electron gun with a record-high accelerat-ing gradient at the CsK2Sb photocathode (i.e. ~ 20 MV/m) generating a record-high bunch charge (i.e., 2 nC). We briefly describe the system and then detail our experimental results.

Slides WEOAB02 [28.500 MB]

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAB02

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WEPMW027

The ERL-based Design of Electron-Hadron Collider eRHIC

2482

V. Ptitsyn, E.C. Aschenauer, I. Ben-Zvi, J.S. Berg, M. Blaskiewicz, S.J. Brooks, K.A. Brown, J.C. Brutus, O.V. Chubar, A.V. Fedotov, D.M. Gassner, H. Hahn, Y. Hao, A. Hershcovitch, H. Huang, W.A. Jackson, Y.C. Jing, R.F. Lambiase, V. Litvinenko, C. Liu, Y. Luo, G.J. Mahler, B. Martin, G.T. McIntyre, W. Meng, F. Méot, T.A. Miller, M.G. Minty, B. Parker, I. Pinayev, V.H. Ranjbar, T. Roser, J. Skaritka, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, E. Wang, G. Wang, H. Witte, Q. Wu, C. Xu, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Recent developments of the ERL-based design of future high luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (L ~ 10³³ cm^-2 s^-1) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design (L > 10³⁴ cm^-2 s^-1) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW027

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THPOY048

NSLS-II Active Interlock System and Post-Mortem Architecture

4214

K. Ha, E.B. Blum, W.X. Cheng, J. Choi, Y. Hu, D. Padrazo, S. Seletskiy, O. Singh, R.M. Smith, J. Tagger, Y. Tian, G. Wang, T. Yang
BNL, Upton, Long Island, New York, USA

The NSLS-II at Brookhaven National Laboratory (BNL) started the user beam service in early 2015, and is currently operating 13 of the insertion device (ID) and beamlines as well as constructing new beamlines. The fast machine protection consists of an active interlock system (AIS), beam position monitor (BPM), cell controller (CCs) and front-end (FE) systems. The AIS measures the electron beam envelop and the dumps the beam by turning off RF system, and then the diagnostic system provides the post-mortem data for an analysis of which system caused the beam dump and the machine status analysis. NSLS-II post-mortem system involves AIS, CCs, BPMs, radio frequency system (RFs), power supply systems (PSs) as well as the timing system. This paper describes the AIS architecture and PM performance for NSLS-II safe operations.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY048

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