TY - JOUR
T1 - Study on a long-life photocathode with an CsBr protective layer for an rf electron gun
AU - Ono, Hiroya
AU - Miyamatsu, Junya
AU - Tamba, Tomoaki
AU - Sakaue, Kazuyuki
AU - Washio, Masakazu
AU - Iijima, Hokuto
AU - Zen, Heishun
N1 - Publisher Copyright:
© 2019 The Japan Society of Applied Physics.
PY - 2019
Y1 - 2019
N2 - A photocathode with a high quantum efficiency (Q.E.) and long lifetime can be fabricated by evaporating a protective layer onto a high Q.E. semiconductor photocathode. In this study we tried to improve the stability and lifetime of a Cs-Te photocathode by coating a CsBr protective layer of 20 nm in thickness over the surface. After the protective layer was applied, we measured the Q.E. of the photocathode and the lifetime in the evaporation chamber. The Q.E. of the coated Cs-Te was confirmed to be about 0.80% and to remain unchanged for a period of longer than 25 d. The effectiveness of the protective layer against exposure of the Cs-Te photocathode to oxygen gas was also confirmed for the first time. Our experiments were the first to show a lifetime improvement of a photocathode installed inside an rf gun compared to the same type of photocathode with no protective coating.
AB - A photocathode with a high quantum efficiency (Q.E.) and long lifetime can be fabricated by evaporating a protective layer onto a high Q.E. semiconductor photocathode. In this study we tried to improve the stability and lifetime of a Cs-Te photocathode by coating a CsBr protective layer of 20 nm in thickness over the surface. After the protective layer was applied, we measured the Q.E. of the photocathode and the lifetime in the evaporation chamber. The Q.E. of the coated Cs-Te was confirmed to be about 0.80% and to remain unchanged for a period of longer than 25 d. The effectiveness of the protective layer against exposure of the Cs-Te photocathode to oxygen gas was also confirmed for the first time. Our experiments were the first to show a lifetime improvement of a photocathode installed inside an rf gun compared to the same type of photocathode with no protective coating.
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U2 - 10.7567/1347-4065/ab170d
DO - 10.7567/1347-4065/ab170d
M3 - Article
AN - SCOPUS:85070783308
VL - 58
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 6
M1 - 066005
ER -