Recent Results on the Performance of Cs3Sb Photocathodes in the PHIN RF-Gun

For the CLIC drive beam a photoinjector option is under study at CERN as an alternative to the thermionic electron gun in the CLIC baseline design. The CLIC drive beam requires a high bunch charge of 8.4 nC and 0.14 ms long trains with 2 ns bunch spacing, which is challenging for a photoinjector. In particular the required long and high intensity laser pulses cause a degradation of the beam quality during the frequency conversion process, which generates the ultra-violet laser beam needed for standard Cs2Te photocathodes. To overcome this issue Cs3Sb cathodes sensitive to green light have been studied at the high-charge PHIN photoinjector since a few years. In this paper recent measurements of fundamental properties of Cs3Sb photocathodes such as quantum efficiency, cathode lifetime and dark current from summer 2014 will be presented, and compared with previous measurements and with the performance of Cs2Te photocathodes