The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Yoskowitz, J.T. AU - Grames, J.M. AU - Hansknecht, J. AU - Hernandez-Garcia, C. AU - Krafft, G.A. AU - Palacios Serrano, G.G. AU - Poelker, M. AU - Stutzman, M.L. AU - Suleiman, R. AU - Wijethunga, S.A.K. AU - van der Geer, S.B. ED - Liu, Lin ED - Byrd, John M. ED - Neuenschwander, Regis T. ED - Picoreti, Renan ED - Schaa, Volker R. W. TI - Improving the Operational Lifetime of the CEBAF Photo-Gun by Anode Biasing J2 - Proc. of IPAC2021, Campinas, SP, Brazil, 24-28 May 2021 CY - Campinas, SP, Brazil T2 - International Particle Accelerator Conference T3 - 12 LA - english AB - The operating lifetime of GaAs-based photocathodes in DC high voltage electron photo-guns is dominated by the ionization rate of residual beamline gas molecules. In this work, experiments were performed to quantify the improvement in photocathode charge lifetime by biasing the photo-gun anode with a positive voltage, which repels ions generated downstream of the anode. The photo-cathode charge lifetime improved by almost a factor of two when the anode was biased compared to the usual grounded configuration. Simulations were performed using the particle tracking code General Particle Tracer (GPT) with a new custom element. The simulation results showed that both the number and energy of ions play a role in the pattern of QE degradation. The experiment results and conclusions supported by GPT simulations will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2840 EP - 2842 KW - cathode KW - laser KW - simulation KW - electron KW - gun DA - 2021/08 PY - 2021 SN - 2673-5490 SN - 978-3-95450-214-1 DO - doi:10.18429/JACoW-IPAC2021-WEPAB104 UR - https://jacow.org/ipac2021/papers/wepab104.pdf ER -