IPAC2013 - List of Authors (Skaritka, J.)

Paper	Title	Page
MOPFI080	Fabrication, Transport and Characterization of Cesium Potassium Antimonide Cathode in Electron Guns	461
	T. Rao, S.A. Belomestnykh, I. Ben-Zvi, X. Liang, I. Pinayev, B. Sheehy, J. Skaritka, J. Smedley, E. Wang, T. Xin BNL, Upton, Long Island, New York, USA R.R. Mammei, J.L. McCarter, M. Poelker JLAB, Newport News, Virginia, USA M. Ruiz-Osés Stony Brook University, Stony Brook, USA
	a number of accelerator applications need high current, low emittance and high brightness electron beams. Recent studies have shown cesium potassium antimonide to be a robust photocathode capable of producing high peak and average currents. However, for some applications, the UHV conditions required for producing these cathodes necessitate their fabrication site to be physically removed from the gun location and the cathode to be transferred between the two sites in UHV load-lock chambers. We have fabricated two cathodes at BNL, transported and tested them in DC gun at JLab at 100 kV and 200 kV. These cathodes have delivered up to 8A/cm² without significant degradation. Localized changes in the QE have been attributed to heating due to laser, increasing the QE at lower laser power, but damaging the cathode at higher power. Two more load-lock chambers have been built to transport and insert similar cathodes in SRF guns operating at 700 MHz and 112 MHz for the first time. In this paper, we will describe the design of the load-lock chambers, transfer mechanisms, transport of the cathodes over ~ 1000 km and the cathode performance in gun environment.

TUPFI081	Progress with Coherent Electron Cooling Proof-Of-Principle Experiment	1535
	I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, L. DeSanto, A. Elizarov, C. Folz, D.M. Gassner, Y. Hao, R.L. Hulsart, Y.C. Jing, D. Kayran, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, R.J. Michnoff, T.A. Miller, M.G. Minty, P. Orfin, A. Pendzick, F. Randazzo, T. Rao, T. Roser, J. Sandberg, B. Sheehy, J. Skaritka, K.S. Smith, L. Snydstrup, R. Than, R.J. Todd, J.E. Tuozzolo, G. Wang, D. Weiss, M. Wilinski, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA G.I. Bell, J.R. Cary, K. Paul, B.T. Schwartz, S.D. Webb Tech-X, Boulder, Colorado, USA C.H. Boulware, T.L. Grimm, R. Jecks, N. Miller Niowave, Inc., Lansing, Michigan, USA M.A. Kholopov, P. Vobly BINP SB RAS, Novosibirsk, Russia M. Poelker JLAB, Newport News, Virginia, USA
	We conduct proof-of-the-principle experiment of coherent electron cooling (CEC), which has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. In this paper, we present the progress with experimental equipment including the first tests of the electron gun and the magnetic measurements of the wiggler prototype. We describe current design status as well as near future plans.

WEPWO047	A Double Quarter-Wave Deflecting Cavity for the LHC	2408
	R. Calaga CERN, Geneva, Switzerland S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404 An asymmetric quarter wave deflecting cavity at 400 MHz for crab crossing in the LHC was already proposed in 2011. Due to improved cancellation of on-axis longitudinal field and the higher order components of the deflecting field, a symmetric version is now considered as the baseline for the quarter wave geometry. Relevant RF properties of the symmetric cavity are compared to the original asymmetric cavity. Some aspects of input coupler design, higher order modes, multipacting and frequency tuning are also addressed.

WEPWO050	Mechanical Study of 400 MHz Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade	2417
	B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu BNL, Upton, Long Island, New York, USA L. Alberty Vieira, R. Calaga CERN, Geneva, Switzerland T.L. Grimm Niowave, Inc., Lansing, Michigan, USA
	A prototype double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. A finite element model is used to simulate the mechanical properties of the crab cavity. The results are presented and a reinforcement concept is proposed to meet the safety requirements. The reinforcement components, as well as the cavity, are presently being fabricated at Niowave Inc.

THPME052	Analysis of the NSLS-II Magnet Measurement Data	3624
	W. Guo, A.K. Jain, S.K. Sharma, J. Skaritka, C.J. Spataro BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 NSLS-II is a third generation 3GeV light source that is under-construction at the Brookhaven National Laboratory. The 30-DBA-cell storage ring will provide micron size beam resulting from the 1nm emittance. Recently the last magnet was received and the completion of girder installation in the tunnel is foreseeable in a few months. In this paper we will briefly review the physics considerations for the magnet specifications, the major field quality related issues that arose during the fabrication process. Our emphasis will be on the statistical analysis of the magnet measurement results and comparison with the design tolerances.

Paper

Title

Page

Fabrication, Transport and Characterization of Cesium Potassium Antimonide Cathode in Electron Guns

461

T. Rao, S.A. Belomestnykh, I. Ben-Zvi, X. Liang, I. Pinayev, B. Sheehy, J. Skaritka, J. Smedley, E. Wang, T. Xin
BNL, Upton, Long Island, New York, USA
R.R. Mammei, J.L. McCarter, M. Poelker
JLAB, Newport News, Virginia, USA
M. Ruiz-Osés
Stony Brook University, Stony Brook, USA

a number of accelerator applications need high current, low emittance and high brightness electron beams. Recent studies have shown cesium potassium antimonide to be a robust photocathode capable of producing high peak and average currents. However, for some applications, the UHV conditions required for producing these cathodes necessitate their fabrication site to be physically removed from the gun location and the cathode to be transferred between the two sites in UHV load-lock chambers. We have fabricated two cathodes at BNL, transported and tested them in DC gun at JLab at 100 kV and 200 kV. These cathodes have delivered up to 8A/cm² without significant degradation. Localized changes in the QE have been attributed to heating due to laser, increasing the QE at lower laser power, but damaging the cathode at higher power. Two more load-lock chambers have been built to transport and insert similar cathodes in SRF guns operating at 700 MHz and 112 MHz for the first time. In this paper, we will describe the design of the load-lock chambers, transfer mechanisms, transport of the cathodes over ~ 1000 km and the cathode performance in gun environment.

TUPFI081

Progress with Coherent Electron Cooling Proof-Of-Principle Experiment

1535

I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, K.A. Brown, J.C. Brutus, L. DeSanto, A. Elizarov, C. Folz, D.M. Gassner, Y. Hao, R.L. Hulsart, Y.C. Jing, D. Kayran, R.F. Lambiase, V. Litvinenko, G.J. Mahler, M. Mapes, W. Meng, R.J. Michnoff, T.A. Miller, M.G. Minty, P. Orfin, A. Pendzick, F. Randazzo, T. Rao, T. Roser, J. Sandberg, B. Sheehy, J. Skaritka, K.S. Smith, L. Snydstrup, R. Than, R.J. Todd, J.E. Tuozzolo, G. Wang, D. Weiss, M. Wilinski, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
G.I. Bell, J.R. Cary, K. Paul, B.T. Schwartz, S.D. Webb
Tech-X, Boulder, Colorado, USA
C.H. Boulware, T.L. Grimm, R. Jecks, N. Miller
Niowave, Inc., Lansing, Michigan, USA
M.A. Kholopov, P. Vobly
BINP SB RAS, Novosibirsk, Russia
M. Poelker
JLAB, Newport News, Virginia, USA

We conduct proof-of-the-principle experiment of coherent electron cooling (CEC), which has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. In this paper, we present the progress with experimental equipment including the first tests of the electron gun and the magnetic measurements of the wiggler prototype. We describe current design status as well as near future plans.

WEPWO047

A Double Quarter-Wave Deflecting Cavity for the LHC

2408

R. Calaga
CERN, Geneva, Switzerland
S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
An asymmetric quarter wave deflecting cavity at 400 MHz for crab crossing in the LHC was already proposed in 2011. Due to improved cancellation of on-axis longitudinal field and the higher order components of the deflecting field, a symmetric version is now considered as the baseline for the quarter wave geometry. Relevant RF properties of the symmetric cavity are compared to the original asymmetric cavity. Some aspects of input coupler design, higher order modes, multipacting and frequency tuning are also addressed.

WEPWO050

Mechanical Study of 400 MHz Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade

2417

B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu
BNL, Upton, Long Island, New York, USA
L. Alberty Vieira, R. Calaga
CERN, Geneva, Switzerland
T.L. Grimm
Niowave, Inc., Lansing, Michigan, USA

A prototype double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. A finite element model is used to simulate the mechanical properties of the crab cavity. The results are presented and a reinforcement concept is proposed to meet the safety requirements. The reinforcement components, as well as the cavity, are presently being fabricated at Niowave Inc.

THPME052

Analysis of the NSLS-II Magnet Measurement Data

3624

W. Guo, A.K. Jain, S.K. Sharma, J. Skaritka, C.J. Spataro
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
NSLS-II is a third generation 3GeV light source that is under-construction at the Brookhaven National Laboratory. The 30-DBA-cell storage ring will provide micron size beam resulting from the 1nm emittance. Recently the last magnet was received and the completion of girder installation in the tunnel is foreseeable in a few months. In this paper we will briefly review the physics considerations for the magnet specifications, the major field quality related issues that arose during the fabrication process. Our emphasis will be on the statistical analysis of the magnet measurement results and comparison with the design tolerances.