Title :
Studies of photo-emission and field emission in an rf photo-injector with a high quantum efficiency photo-cathode
Author :
Hartung, W. ; Carneiro, J.-P. ; Edwards, D. ; Edwards, H. ; Finley, D. ; Fitch, M.J. ; Kuchnir, M. ; Michelato, P. ; Sertore, D.
Author_Institution :
Fermi Nat. Accelerator Lab., Batavia, IL, USA
Abstract :
The facility at Fermilab was used to develop, fabricate, and commission an RF gun for the TeSLA Test Facility Linac. A time dependence is observed in the photo-emission and field emission from the photo-injector at Fermilab. The focussing solenoids can be adjusted to cause the QE and dark current to increase or decrease with time. The observed variation is in excess of a factor of 5 in the QE and a factor of 10 in the dark current, with time constants measured in hours. The evidence suggests that the source of the time-dependent behaviour is the Cs2Te cathode
Keywords :
accelerator RF systems; accelerator magnets; caesium compounds; electron accelerators; electron beam focusing; electron guns; field emission; linear colliders; photocathodes; photoemission; Cs2Te; Fermilab; RF gun; TeSLA test facility linear collider; dark current; field emission; focussing solenoids; high quantum efficiency photocathode; photoemission; radiofrequency photoinjector; Cathodes; Coatings; Electron beams; Laser beams; Linear particle accelerator; Optical films; Optical pulses; Pulse measurements; Radio frequency; Temperature;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.987336
