Heat load of a P-doped GaAs photocathode in SRF electron gun

Conference · Sun May 23 04:00:00 EDT 2010

OSTI ID:1013487

Wang, E; Ben-Zvi, I; Kewisch, J; Burrill, A; Rao, T; Wu, Q; Jain, A; Gupta, R; Holmes, D

Many efforts were made over the last decades to develop a better polarized electron source for the high energy physics. Several laboratories operate DC guns with the Gallium-Arsenide photo-cathode, which yield a highly polarized electron beam. However, the beam's emittance might well be improved using a Superconducting RF electron gun, which delivers beams of higher brightness than DC guns does, because the field gradient at the cathode is higher. SRF guns with metal cathodes and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used: an experiment to do so in a superconducting RF gun is under way at BNL. Since the cathode will be normal conducting, the problem about the heat load stemming from the cathode arises. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and the verification by measuring the quality factor of the gun with and without cathode.

• Research Organization: Brookhaven National Laboratory (BNL) Relativistic Heavy Ion Collider
• Sponsoring Organization: DOE - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1013487
• Report Number(s): BNL--90778-2010-CP; KB0202011
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
BNL
BRIGHTNESS
CATHODES
CRYOGENICS
ELECTRIC CONDUCTIVITY
ELECTRON BEAMS
ELECTRON GUNS
ELECTRON SOURCES
ELECTRONS
FORECASTING
HIGH ENERGY PHYSICS
PHOTOCATHODES
QUALITY FACTOR
VERIFICATION
relativistic heavy ion collider