The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Guo, L.Guo. AU - Iijima, H. AU - Kuriki, M. AU - Uchida, K. ED - Koscielniak, Shane ED - Satogata, Todd ED - Schaa, Volker RW ED - Thomson, Jana TI - NEA Surface Activation of GaAs Photocathode with CO2 J2 - Proc. of IPAC2018, Vancouver, BC, Canada, April 29-May 4, 2018 C1 - Vancouver, BC, Canada T2 - International Particle Accelerator Conference T3 - 9 LA - english AB - NEA (negative electron affinity)-GaAs cathode is able to generate highly spin polarized electron beam more than 90%. The NEA activation is performed usually with Cs and O2 or NF3, but the exact structure of the NEA surface is not known. In this paper, we performed the NEA activation on a cleaned GaAs surface with CO2, CO, N2, and O2 gases and compared the results to improve our understanding on the NEA surface. We found that CO2 activated the cathode, but N2 and CO did not. By analyzing CO2 activation, we found that atomic oxygen activates the NEA surface and CO degrades the NEA surface simultaneously. We found that the NEA activation ability of atomic oxygen is almost a half of that of O2 molecule.* PB - JACoW Publishing CP - Geneva, Switzerland SP - 4590 EP - 4593 KW - cathode KW - experiment KW - electron KW - ECR KW - emittance DA - 2018/06 PY - 2018 SN - 978-3-95450-184-7 DO - 10.18429/JACoW-IPAC2018-THPMK116 UR - http://jacow.org/ipac2018/papers/thpmk116.pdf ER -