The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Wang, E. AU - Hao, Y. AU - Jing, Y.C. AU - Litvinenko, V. AU - Pinayev, I. AU - Rao, T. AU - Skaritka, J. AU - Wang, G. AU - Xin, T. ED - Schaa, Volker RW ED - Power, Maria ED - Shiltsev, Vladimir ED - White, Marion TI - K2CsSb Photocathode Performance in QWR SRF Gun J2 - Proc. of NAPAC2016, Chicago, IL, USA, October 9-14, 2016 C1 - Chicago, IL, USA T2 - North American Particle Accelerator Conference T3 - 3 LA - english AB - In 2016 run of Coherent Electron Cooling, we have successfully tested the performance of a number of K2CsSb cathodes. These cathodes with QE of 6%-10% were fabricated in Instrumentation Division, a few miles away, transported to RHIC tunnel under UHV conditions, attached to the CeC gun, kept in storage, and inserted in the gun as needed. A maximum bunch charge of 4.6 nC was generated in the gun when the QE was 1.8 %. With careful conditioning at increasing accelerating fields, it was possible to maintain the QE of several cathodes for more than a week. For the cathodes that experienced degradation, the primary cause was multipacting when the power into the gun was increased. In the initial runs, the entire 20 mm substrate face was coated with the cathode material causing cathode induced multipacting. For subsequent measurements, the substrate was masked to coat only the central 9 mm of the substrate. By optimizing the procedure for boosting the power to the gun and covering all viewports to minimize dark current, we were able to minimize QE degradation. In this paper we discuss the cathode preparation, transfer to the gun and operational experience with the cathodes in 112 MHz gun. PB - JACoW CP - Geneva, Switzerland SP - 1042 EP - 1044 KW - cathode KW - ion KW - gun KW - multipactoring KW - vacuum DA - 2017/01 PY - 2017 SN - 978-3-95450-180-9 DO - 10.18429/JACoW-NAPAC2016-WEPOB67 UR - https://jacow.org/napac2016/papers/wepob67.pdf ER -