IPAC2018 - List of Authors (Uchida, K.)

Paper	Title	Page
THPMK116	NEA Surface Activation of GaAs Photocathode with CO2	4590
	L.Guo. Guo UVSOR, Okazaki, Japan H. Iijima Tokyo University of Science, Tokyo, Japan M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan K. Uchida Cosylab Japan, Ibaraki, Japan
	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.* *L. Guo, M. Kuriki, H. Iijima, K. Uchida. "NEA surface activation of GaAs photocathode with different gases", Surface Science 664C (2017) pp. 65-69.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK116
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Paper

Title

Page

NEA Surface Activation of GaAs Photocathode with CO2

4590

L.Guo. Guo
UVSOR, Okazaki, Japan
H. Iijima
Tokyo University of Science, Tokyo, Japan
M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
K. Uchida
Cosylab Japan, Ibaraki, Japan

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.*
*L. Guo, M. Kuriki, H. Iijima, K. Uchida. "NEA surface activation of GaAs photocathode with different gases", Surface Science 664C (2017) pp. 65-69.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK116

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)