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Nishihara, Katsunobu*; Sunahara, Atsushi*; Sasaki, Akira; Tanuma, Hajime*; Koike, Fumihiro*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Shimada, Yoshinori*
Reza Kenkyu, 36(11), p.690 - 699, 2008/11
The critical issue for realization of a laser produced plasma (LPP) extreme ultraviolet (EUV) light source is the conversion efficiency (CE) from incident laser power to EUV radiation of 13.5 nm wavelength. From an atomic physics, we show that tin is the most suitable radiation material compared with xenon and lithium. We also show the optimization of laser and target conditions to obtain high CE using a power balance model. We propose a double-pulse irradiation scheme for high CE using a carbon dioxides laser and a droplet target.
Izawa, Yasukazu*; Nishihara, Katsunobu*; Tanuma, Hajime*; Sasaki, Akira; Murakami, Masakatsu*; Sunahara, Atsushi*; Nishimura, Hiroaki*; Fujioka, Shinsuke*; Aota, Tatsuya*; Shimada, Yoshinori*; et al.
Journal of Physics; Conference Series, 112, p.042047_1 - 042047_4, 2008/00
Times Cited Count：8 Percentile：93.45(Physics, Fluids & Plasmas)In the development of a high power EUV source used in the EUV lithography system, we have been constructed EUV database of laser-produced tin plasma by the theoretical and experimental studies. On the basis of our understanding, the optimum conditions of lasers and plasmas were clarified, and we proposed the guidelines of laser plasma to obtain clean, efficient and high power EUV source for the practical EUV lithography system. In parallel to such studies, novel targets and high power laser system to generate the optimized EUV source plasma have been developed.
Nishihara, Katsunobu*; Sunahara, Atsushi*; Sasaki, Akira; Nunami, Masanori*; Tanuma, Hajime*; Fujioka, Shinsuke*; Shimada, Yoshinori*; Fujima, Kazumi*; Furukawa, Hiroyuki*; Kato, Takako*; et al.
Physics of Plasmas, 15(5), p.056708_1 - 056708_11, 2008/00
Times Cited Count：122 Percentile：97.47(Physics, Fluids & Plasmas)Sunahara, Atsushi*; Sasaki, Akira; Tanuma, Hajime*; Nishihara, Katsunobu*; Nishikawa, Takeshi*; Koike, Fumihiro*; Fujioka, Shinsuke*; Aota, Tatsuya*; Yamaura, Michiteru*; Shimada, Yoshinori*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(11), p.920 - 926, 2007/11
We study the EUV emission from laser produced Sn plasmas using the 1D and 2D radiation hydrodynamics simulation, for the development of EUV source for the next generation semiconductor lithography. The opacity and emissivity of the plasma used in the simulation are calculated by a detailed atomic model, with the accurate wavelength of emission lines obtained from the detailed spectroscopic measurements. Calculation is shown to reproduce the experimental spectrum and conversion efficiency reasonably, including the effect of photo pumping which modifies the EUV emission spectrum in the case with a long scale length of the plasmas.
Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Sasaki, Akira; Sunahara, Atsushi*; Okuno, Tomoharu*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Tao, Y.*; Shimada, Yoshinori*; et al.
Physical Review Letters, 95(23), p.235004_1 - 235004_4, 2005/12
Times Cited Count：147 Percentile：95.57(Physics, Multidisciplinary)no abstracts in English
Shimada, Yoshinori*; Nishimura, Hiroaki*; Nakai, Mitsuo*; Hashimoto, Kazuhisa*; Yamaura, Michiteru*; Tao, Y.*; Shigemori, Keisuke*; Okuno, Tomoharu*; Nishihara, Katsunobu*; Kawamura, Toru*; et al.
Applied Physics Letters, 86(5), p.051501_1 - 051501_3, 2005/01
Times Cited Count：113 Percentile：94.31(Physics, Applied)no abstracts in English
Yamada, Tomonori; Daido, Hiroyuki; Kawamura, Hiroshi; Shimada, Yoshinori*
no journal, ,
no abstracts in English
Mikami, Katsuhiro; Kurahashi, Shinri*; Kitamura, Toshiyuki*; Hasegawa, Noboru; Okada, Hajime; Kondo, Shuji; Kotyaev, O.*; Shimada, Yoshinori*; Kawachi, Tetsuya
no journal, ,
A lot of infrastructure constructions were built in the 1940s and 1950s in Japan and these decrepitude are seriously concerned that leading to a serious accident. Recently, a novel inspection method using laser systems which consists of impact laser and detection laser, is energetically developing because of its significant advantages. A role of the impact laser is to induce the vibration on concrete walls by the high energy laser pulse behaving like hammering. Then, the detection laser set in laser differential interferometer that which detects the vibration of the concrete surface. For putting into actual utilization, the inspection speed which is about several ten meters per night should be improved for the exceedingly-long train-tunnels. The inspection speed of impact laser and detection systems is required a high-frequency measurement. In this study, we developed a new prototype inspection system to realize high speed inspection for defects inside concrete.
Yamada, Tomonori; Suzuki, Hiroshi; Hanari, Toshihide; Shibata, Takuya; Nishimura, Akihiko; Koyama, Shinichi; Daido, Hiroyuki; Shimada, Yoshinori*; Kotyaev, O.*; Kurahashi, Shinri*
no journal, ,
no abstracts in English
Yamada, Tomonori; Hanari, Toshihide; Shibata, Takuya; Nishimura, Akihiko; Koyama, Shinichi; Daido, Hiroyuki; Shimada, Yoshinori*; Kotyaev, O.*; Kurahashi, Shinri*
no journal, ,
To decommission the Fukushima Daiichi Nuclear Power Station, it is essential to dispose radioactive wastes resulting from the disaster. The wastes cannot be diagnosed manually on account of exposure to high-dose rate. Thus development of remote diagnostic technologies for the wastes must be indispensable. The aim of the present work is to develop a method of evaluating physical and mechanical properties of heat-deteriorated concrete. Non-contact measurement of the propagation time of ultrasonic waves through the concrete was performed with an LDV. The experimental result shows that the propagation time becomes longer as a result of heat processing. The difference in propagation time depends on the changes in physical and mechanical properties of concrete suffered from heat processing. From viewpoint of remote diagnostic technologies for the decommissioning, an LDV is a promising tool to evaluate heat-deterioration of concrete by measuring ultrasonic waves propagating through a concrete.
Yamada, Tomonori; Nguyen, P. L.; Hanari, Toshihide; Shibata, Takuya; Nishimura, Akihiko; Koyama, Shinichi; Daido, Hiroyuki; Shimada, Yoshinori*; Kotyaev, O.*; Kurahashi, Shinri*
no journal, ,
For decommissioning of the Fukushima Daiichi Nuclear Power Station (NPS) of Tokyo Electric Power Company, Incorporated, it is essential to dispose radioactive wastes resulted from the accident. The wastes cannot be diagnosed and removed manually on account of exposure to high radiation dose. Thus research and development of remote techniques for wastes is indispensable. In terms of remote handling, a fiber delivered laser beam can access into the narrow gap and process the object without repulsive force. That is a powerful advantage of laser processing. We are now developing remote laser techniques for sensing and sampling at the Naraha Remote Technology Development Center.
Hasegawa, Noboru*; Nishikino, Masaharu*; Mikami, Katsuhiro*; Okada, Hajime*; Kondo, Shuji*; Kawachi, Tetsuya*; Shimada, Yoshinori*; Kurahashi, Shinri*; Kitamura, Toshiyuki*; Kotyaev, O.*; et al.
no journal, ,
no abstracts in English
Kase, Kiwamu*; Saito, Norihito*; Wada, Satoshi*; Midorikawa, Katsumi*; Shimada, Yoshinori*; Kurahashi, Shinri*; Kawachi, Tetsuya*; Nishikino, Masaharu*; Daido, Hiroyuki; Yamada, Tomonori
no journal, ,
no abstracts in English
Nishimura, Akihiko; Yamada, Tomonori; Shimada, Yoshinori*; Morishita, Hideki*; Yoshida, Minoru*
no journal, ,
In NARREC-JAEA, vibration characteristics of a water tank due to water level rising are measured. Laser Doppler vibration displacement sensor is used. This technique can be applied for monitoring internal pressure of a shielded radioactive material capsule.
