FZD, Dresden
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin
MBI, Berlin
More and more electron accelerator projects for FELs, ERLs or 4th generation light sources require “super” electron beam with high brightness, low emittance, and high average current. Under this background, much attention is paid on the research and development of new electron sources. Superconducting RF photoinjector was designed within a collaboration of BESSY, DESY, FZD, and MBI to improve the beam quality for ELBE IR-FEL users, and at the same time to test this kind of promising injector concept. The main design parameters of this gun are the final electron energy of 9.5 MeV, 1 mA average current, and transverse normalized emittances (rms) of 1 mm mrad at 77 pC and 2.5 mm mrad at 1 nC bunch charge. In this paper the results of the RF and beam parameter measurements with Cs2Te photo cathodes will be presented, and the experience for the gun running gained at the first experiments will be concluded, including the life time and compatibility of the normal conducting photocathode in SC cavity, the coupling of high average power into the gun, and the excitation of higher-order modes in the cavity.
