ERL2015 - List of Authors (Belomestnykh, S.A.)

Paper

Title

Page

Status and Commissioning Results of the R&D ERL at BNL

10

D. Kayran, Z. Altinbas, D.R. Beavis, S.A. Belomestnykh, I. Ben-Zvi, S. Deonarine, D.M. Gassner, R.C. Gupta, H. Hahn, L.R. Hammons, C. Ho, J.P. Jamilkowski, P. K. Kankiya, N. Laloudakis, R.F. Lambiase, V. Litvinenko, G.J. Mahler, L. Masi, G.T. McIntyre, T.A. Miller, J. Morris, D. Phillips, V. Ptitsyn, T. Rao, T. Seda, B. Sheehy, L. Smart, K.S. Smith, T. Srinivasan-Rao, A.N. Steszyn, R. Than, E. Wang, D. Weiss, H. Xie, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi, L.R. Hammons, D. Kayran, V. Litvinenko, V. Ptitsyn
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
An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is presently under commissioning at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. The injector subsystems tests and installation were finished in fall 2013. The injector includes: SRF photoelectron gun with 1 MW amplifier, 10W green drive-laser system, multi-alkaline cathode deposition system, cathode transport system, beam instrumentation and control. * The first photo current from ERL SRF gun has been observed in fall 2014 after second attempt. Completion of the ERL returning loop components installation is scheduled for April 2015 following full power ERL commissioning. After ERL commissioning in BLDG912 the ERL will be relocated to RHIC IP2 to be used as low energy RHIC electron cooler.
* D.Kayran et al., First test results from SRF photoinjector for the R&D ERL at BNL, IPAC'14, pp. 748-750

Slides MOPDTH014 [13.777 MB]

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TUICLH1027

Characterization of Multi-alkali Antimonide Cathode at Cryogenic Temperatures and its Performance in SRF Gun

H.M. Xie
PKU, Beijing, People's Republic of China
S.A. Belomestnykh, I. Ben-Zvi, D. Kayran, G.T. McIntyre, B. Sheehy, R. Than, E. Wang, D. Weiss, W. Xu
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.
An alkali antimonide photocathode was tested in BNL 704 MHz SRF gun. The cathode QE and lifetime were measured inside the gun. We also observed a reduction on the QE upon cooling down to cryogenic temperature. In this paper, we propose an analytical model and present a Monte-Carlo simulation code to explain this QE decrease. Both results compared with experiments. Effect of cooling the cathode to cryogenic temperature and Schottky effect on QE will be discussed.

Slides TUICLH1027 [1.815 MB]

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TUIDLH1036

Commissioning Program for the 704 MHz SRF Gun at BNL

W. Xu, S.A. Belomestnykh, I. Ben-Zvi, D. Kayran
BNL, Upton, Long Island, New York, USA

A 704 MHz superconducting RF photoemission electron gun for the R&D ERL project is under commissioning at BNL. It successfully generated the first photoemission beam in November 2014. The BNL SRF gun cavity operates well in CW mode up to 2 MV. However, its performance with inserted cathode stalk suffered due to multipacting in the quarter-wavelength choke-joint. A new multipacting-free cathode stalk was designed and tested. The test results proved that it is a truly “multipacting-free” stalk. With the new cathode, the gun is able to operate in CW mode. The total conditioning time of the new cathode stalk is very short. This paper describes configuration of the SRF gun test and the sub-systems. RF and thermal design of new cathode stalk and its conditioning results are presented. Finally, we report the latest results of the SRF gun commissioning, including the cavity performance, cathode QE measurements, beam current/energy measurements.

Slides TUIDLH1036 [5.226 MB]

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WEICLH2061

SRF Cavities for High Current ERLs

W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn
BNL, Upton, Long Island, New York, USA

The electron-ion collider eRHIC, proposed at BNL, requires superconducting RF cavities, which are able to support high average current beams. Two types of ERL lattices were designed for eRHIC. The first one is a conventional lattice, and the other one is a non-scaling FFAG lattice, which was proposed recently. For the conventional lattice with up to eight ERL passes, a 704 MHz 5-cell BNL3 cavity was designed, fabricated and tested vertically at BNL. The FFAG-based eRHIC design requires a high-current low-frequency SRF energy recovery linac with up to 16 passes. A 422 MHz 5-cell cavity (BNL4) was designed for for this lattice. This paper addresses development of the SRF cavities for eRHIC, including the cavity design, fabrication and test results. Beam-break-up (BBU) analysis for these cavities is presented as well. An HOM damping scheme for achiving low higher-order-modes’ impedance is proposed. HOM couplers were designed for these high current SRF cavities. HOM coupler prototypes were fabricated and tested.

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Paper	Title	Page
MOPDTH014	Status and Commissioning Results of the R&D ERL at BNL	10
	D. Kayran, Z. Altinbas, D.R. Beavis, S.A. Belomestnykh, I. Ben-Zvi, S. Deonarine, D.M. Gassner, R.C. Gupta, H. Hahn, L.R. Hammons, C. Ho, J.P. Jamilkowski, P. K. Kankiya, N. Laloudakis, R.F. Lambiase, V. Litvinenko, G.J. Mahler, L. Masi, G.T. McIntyre, T.A. Miller, J. Morris, D. Phillips, V. Ptitsyn, T. Rao, T. Seda, B. Sheehy, L. Smart, K.S. Smith, T. Srinivasan-Rao, A.N. Steszyn, R. Than, E. Wang, D. Weiss, H. Xie, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi, L.R. Hammons, D. Kayran, V. Litvinenko, V. Ptitsyn 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 An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is presently under commissioning at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. The injector subsystems tests and installation were finished in fall 2013. The injector includes: SRF photoelectron gun with 1 MW amplifier, 10W green drive-laser system, multi-alkaline cathode deposition system, cathode transport system, beam instrumentation and control. * The first photo current from ERL SRF gun has been observed in fall 2014 after second attempt. Completion of the ERL returning loop components installation is scheduled for April 2015 following full power ERL commissioning. After ERL commissioning in BLDG912 the ERL will be relocated to RHIC IP2 to be used as low energy RHIC electron cooler. * D.Kayran et al., First test results from SRF photoinjector for the R&D ERL at BNL, IPAC'14, pp. 748-750
	Slides MOPDTH014 [13.777 MB]
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TUICLH1027	Characterization of Multi-alkali Antimonide Cathode at Cryogenic Temperatures and its Performance in SRF Gun
	H.M. Xie PKU, Beijing, People's Republic of China S.A. Belomestnykh, I. Ben-Zvi, D. Kayran, G.T. McIntyre, B. Sheehy, R. Than, E. Wang, D. Weiss, W. Xu 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. An alkali antimonide photocathode was tested in BNL 704 MHz SRF gun. The cathode QE and lifetime were measured inside the gun. We also observed a reduction on the QE upon cooling down to cryogenic temperature. In this paper, we propose an analytical model and present a Monte-Carlo simulation code to explain this QE decrease. Both results compared with experiments. Effect of cooling the cathode to cryogenic temperature and Schottky effect on QE will be discussed.
	Slides TUICLH1027 [1.815 MB]
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TUIDLH1036	Commissioning Program for the 704 MHz SRF Gun at BNL
	W. Xu, S.A. Belomestnykh, I. Ben-Zvi, D. Kayran BNL, Upton, Long Island, New York, USA
	A 704 MHz superconducting RF photoemission electron gun for the R&D ERL project is under commissioning at BNL. It successfully generated the first photoemission beam in November 2014. The BNL SRF gun cavity operates well in CW mode up to 2 MV. However, its performance with inserted cathode stalk suffered due to multipacting in the quarter-wavelength choke-joint. A new multipacting-free cathode stalk was designed and tested. The test results proved that it is a truly “multipacting-free” stalk. With the new cathode, the gun is able to operate in CW mode. The total conditioning time of the new cathode stalk is very short. This paper describes configuration of the SRF gun test and the sub-systems. RF and thermal design of new cathode stalk and its conditioning results are presented. Finally, we report the latest results of the SRF gun commissioning, including the cavity performance, cathode QE measurements, beam current/energy measurements.
	Slides TUIDLH1036 [5.226 MB]
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WEICLH2061	SRF Cavities for High Current ERLs
	W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn BNL, Upton, Long Island, New York, USA
	The electron-ion collider eRHIC, proposed at BNL, requires superconducting RF cavities, which are able to support high average current beams. Two types of ERL lattices were designed for eRHIC. The first one is a conventional lattice, and the other one is a non-scaling FFAG lattice, which was proposed recently. For the conventional lattice with up to eight ERL passes, a 704 MHz 5-cell BNL3 cavity was designed, fabricated and tested vertically at BNL. The FFAG-based eRHIC design requires a high-current low-frequency SRF energy recovery linac with up to 16 passes. A 422 MHz 5-cell cavity (BNL4) was designed for for this lattice. This paper addresses development of the SRF cavities for eRHIC, including the cavity design, fabrication and test results. Beam-break-up (BBU) analysis for these cavities is presented as well. An HOM damping scheme for achiving low higher-order-modes’ impedance is proposed. HOM couplers were designed for these high current SRF cavities. HOM coupler prototypes were fabricated and tested.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)