First experience with He conditioning of a superconducting rf photoinjector

The recent achievements in the performance of superconducting RF (SRF) photoinjectors have opened a new era development reliable high-brightness CW electron sources. While SRF guns become one most promising technologies, compatibility environment with complex photocathodes remains on forefront modern accelerator science. cavities operate at cryogenic temperatures providing ultra-high vacuum (UHV) highly beneficial for photocathode performance. However, necessity to keep room temperature while being surrounded by cavity walls that are kept creates an additional complexity gun design and operation. volatile chemical compounds used high chance contaminating surfaces cavity. When deposited, such could create centers cold emission which degrade guns. Such circumstance would require in-situ processing techniques restoring This paper presents results successful implementation application He conditioning method restoration using existing photoinjector Brookhaven National Laboratory (BNL). has proven be extremely effective resulted dramatic improvement BNL