Optimizing conversion efficiency and reducing ion energy in a laser-produced Gd plasma

Journal Article · Mon Feb 06 00:00:00 EST 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3684242· OSTI ID:22025431

Cummins, Thomas; Bowen, Li; O'Gorman, Colm; Dunne, Padraig; Sokell, Emma; O'Sullivan, Gerry ^[1]; Otsuka, Takamitsu ^[2]; Yugami, Noboru; Higashiguchi, Takeshi ^[2]; Weihua, Jiang ^[3]; Endo, Akira ^[4]

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1. School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)
2. Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan)
3. Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 (Japan)
4. Research Institute for Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

We have demonstrated an efficient extreme ultraviolet (EUV) source at 6.7 nm by irradiating Gd targets with 0.8 and 1.06 {mu}m laser pulses of 140 fs to 10 ns duration. Maximum conversion efficiency of 0.4% was observed within a 0.6% bandwidth. A Faraday cup observed ion yield and time of flight signals for ions from plasmas generated by each laser. Ion kinetic energy was lower for shorter pulse durations, which yielded higher electron temperatures required for efficient EUV emission, due to higher laser intensity. Picosecond laser pulses were found to be the best suited to 6.7 nm EUV source generation.

• OSTI ID: 22025431
• Journal Information: Applied Physics Letters, Vol. 100, Issue 6; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONVERSION
EFFICIENCY
ELECTRON TEMPERATURE
EXTREME ULTRAVIOLET RADIATION
FARADAY CUPS
GADOLINIUM
IONS
KINETIC ENERGY
LASER TARGETS
LASER-PRODUCED PLASMA
LIGHT SOURCES
PLASMA DIAGNOSTICS
PLASMA PRODUCTION
PULSES
TIME-OF-FLIGHT METHOD