If there is no buster cavity what can we do in longitudinal ..... Cathode. Cooper. Multi-Alkaline. Multi-Alkaline. Long. Pulse shape. (FWHM). 12 psec Sin(x)/x.
Beam Dynamics of SRF Gun Dmitry Kayran
ColliderCollider-Accelerator Department Brookhaven National Laboratory
ERL09 Workshop, Ithaca, June 10, 2009
Why SRF Gun anyway? Low emittance like NC RF photoinjector ( ~1 µm x 1nC) and high average current (0.1-0.5A) in CW mode ERL based FEL, light source needs them both. High vacuum for “free” (cold niobium works like a cryo pump) good for cathode lifetime
But Cathode material may contaminate superconductive gun surface Cathode insertion mechanism is rather complicated (choke design) High average current and 2-5 MeV injection (non- recovered) energy High RF Power must have. BNL example: needs current 0.5 A, available 2 FPC x 0.5 MW after gun energy is limited by power KE
