IPAC2012 - List of Authors (Cole, M.D.)

Paper	Title	Page
WEPPC113	Progress on the High-Current 704 MHz Superconducting RF Cavity at BNL	2486
	W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn, P. Jain BNL, Upton, Long Island, New York, USA C.M. Astefanous, M.D. Cole, J.P. Deacutis, D. Holmes AES, Medford, NY, USA
	Funding: This work was supported by Sotny Brook under contract No. DE-SC0002496 and Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups for the copper prototype, and presents comparison of the experimental results with computer simulations. The progress with the niobium cavity fabrication will also be described.

WEPPC114	Design, Simulation and Conditioning of the Fundamental Power Couplers for BNL SRF Gun	2489
	W. Xu, Z. Altinbas, S.A. Belomestnykh, I. Ben-Zvi, S. Deonarine, D.M. Gassner, J.P. Jamilkowski, P. Kankiya, D. Kayran, N. Laloudakis, L. Masi, G.T. McIntyre, D. Pate, D. Phillips, T. Seda, A.N. Steszyn, T.N. Tallerico, R.J. Todd, D. Weiss, A. Zaltsman BNL, Upton, Long Island, New York, USA M.D. Cole, G.J. Whitbeck AES, Medford, NY, USA
	Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. The 704 MHz SRF gun for the BNL Energy Recovery Linac (ERL) prototype uses two fundamental power couplers (FPCs) to deliver up to total 1 MW of CW RF power into the half-cell cavity. To prepare the couplers for high-power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A room-temperature test stand was configured for conditioning FPCs in full reflection regime with varied phase of the reflecting wave. The FPCs have been conditioned up to 250 kW in pulse mode and 125 kW in CW mode. The multipacting simulations were carried out with Track3P code developed at SLAC. The simulations matched the experimental results very well. This paper presents the FPC RF and thermal design, multipacting simulations and conditioning of the BNL gun FPCs.

Paper

Title

Page

Progress on the High-Current 704 MHz Superconducting RF Cavity at BNL

2486

W. Xu, S.A. Belomestnykh, I. Ben-Zvi, H. Hahn, P. Jain
BNL, Upton, Long Island, New York, USA
C.M. Astefanous, M.D. Cole, J.P. Deacutis, D. Holmes
AES, Medford, NY, USA

Funding: This work was supported by Sotny Brook under contract No. DE-SC0002496 and Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups for the copper prototype, and presents comparison of the experimental results with computer simulations. The progress with the niobium cavity fabrication will also be described.

WEPPC114

Design, Simulation and Conditioning of the Fundamental Power Couplers for BNL SRF Gun

2489

W. Xu, Z. Altinbas, S.A. Belomestnykh, I. Ben-Zvi, S. Deonarine, D.M. Gassner, J.P. Jamilkowski, P. Kankiya, D. Kayran, N. Laloudakis, L. Masi, G.T. McIntyre, D. Pate, D. Phillips, T. Seda, A.N. Steszyn, T.N. Tallerico, R.J. Todd, D. Weiss, A. Zaltsman
BNL, Upton, Long Island, New York, USA
M.D. Cole, G.J. Whitbeck
AES, Medford, NY, USA

Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
The 704 MHz SRF gun for the BNL Energy Recovery Linac (ERL) prototype uses two fundamental power couplers (FPCs) to deliver up to total 1 MW of CW RF power into the half-cell cavity. To prepare the couplers for high-power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A room-temperature test stand was configured for conditioning FPCs in full reflection regime with varied phase of the reflecting wave. The FPCs have been conditioned up to 250 kW in pulse mode and 125 kW in CW mode. The multipacting simulations were carried out with Track3P code developed at SLAC. The simulations matched the experimental results very well. This paper presents the FPC RF and thermal design, multipacting simulations and conditioning of the BNL gun FPCs.