Characteristic improvement of tungsten photocathode by two-wavelength irradiation of the Nd:YAG laser

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.118846· OSTI ID:544513

Ohkubo, K; Nakao, N; Mima, K; Nakai, S ^[1]; Fujita, M; Imasaki, K; Yamanaka, C ^[2]; Watanabe, T; Ishida, T; Ohigashi, N ^[3]; Tsunawaki, Y ^[4]

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1. Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565 (Japan)
2. Institute for Laser Technology, 2-6 Yamada-oka, Suita, Osaka 565 (Japan)
3. Kansai University, 3-5-35 Yamate-cho, Suita, Osaka 564 (Japan)
4. Osaka Sangyo University, 3-1-1 Nakagaichi, Daito, Osaka 574 (Japan)

Metals or metal compounds as photocathodes provide high current density and have a high damage threshold for laser irradiation. In addition, the quantum efficiency of these cathodes is enhanced by heating to a higher operating temperature. The tungsten photocathode heated up to 1400 K and irradiated by 2{omega} (532 nm) of the Nd:YAG laser produced an electron beam with high current density ({approximately}1 kA/cm{sup 2}) and the quantum efficiency was about 10{sup {minus}5}. The fundamental (1064 nm) of a Nd:YAG laser was used to further heat up the cathode instantly; the temperature rise was calculated to be 2000 K in a 10 ps time scale. Compared to the static 1400 K operation, two times enhancement of quantum efficiency was observed. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 544513
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 17 Vol. 70; ISSN 0003-6951; ISSN APPLAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
LASER RADIATION
PHOTOCATHODES
PHOTOEMISSION
QUANTUM EFFICIENCY
RADIATION EFFECTS
TEMPERATURE DEPENDENCE
TUNGSTEN