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Sasaki, Akira; Nishihara, Katsunobu*; Sunahara, Atsushi*; Nishikawa, Takeshi*
Proceedings of SPIE, Vol.9776, p.97762C_1 - 97762C_6, 2016/03
Times Cited Count：1 Percentile：50.59(Optics)For the improvement of efficiency and output of the laser pumped plasma (LPP) extreme ultra-violet (EUV) light source, we present a hydrodynamics model of laser irradiated Sn targets. The model takes liquid/solid to gas transition and mixed phase condition of the flow into account for the calculation of the distribution of the particles produced by the pre-pulse laser irradiation and optimization of the EUV source. Firstly, we investigate the mechanisms of the fragmentation of the target and particle emission, including the effect of the equation of state of Sn, and secondly, an applicable model is proposed based on the analysis.
Sasaki, Akira; Nishimura, Hiroaki*; Onishi, Naofumi*
Purazuma, Kaku Yugo Gakkai-Shi, 91(2), p.166 - 167, 2015/02
no abstracts in English
Sasaki, Akira
Genshiryoku, Ryoshi, Kakuyugo Jiten, 1, p.108 - 109, 2014/12
no abstracts in English
Ozu, Akira; Tachi, Yoshiaki; Arita, Yuji*
Reza Kenkyu, 42(12), p.913 - 917, 2014/12
Laser-induced breakdown spectroscopy (LIBS) analysis has been applied to the molten alloy production process, in which simulated metals (Zr, Cu, Sm, Ce) are used instead of nuclear metallic fuels contained minor actinide (MA), with the aim of in-situ monitoring the elementary composition of the surface of the molten alloy in a chamber and vapor particles generated from the surface of the molten alloy. The variation in the ratio of elementary composition of the surface of the molten alloy in the crucible was successfully observed depending on temperature of the crucible. The elementary composition of the vapor particles appeared in the molten alloy chamber was also measured. The practical experimental results show that LIBS technique is very useful for investigating the elementary composition in the process and understanding the behavior of molten alloy in the crucible.
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：159 Percentile：95.81(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：115 Percentile：94.17(Physics, Applied)no abstracts in English
Sasaki, Akira; Nishihara, Katsunobu*; Murakami, Masakatsu*; Koike, Fumihiro*; Kagawa, Takashi*; Nishikawa, Takeshi*; Fujima, Kazumi*; Kawamura, Toru*; Furukawa, Hiroyuki*
Applied Physics Letters, 85(24), p.5857 - 5859, 2004/12
Times Cited Count：43 Percentile：79.34(Physics, Applied)no abstracts in English
Sasaki, Akira; Utsumi, Takayuki*; Moribayashi, Kengo; Zhidkov, A. G.; Kado, Masataka; Tanaka, Momoko; Hasegawa, Noboru; Kawachi, Tetsuya
Journal de Physique, IV, 11(Pr2), p.Pr2_75 - Pr2_78, 2001/07
no abstracts in English
Sasaki, Akira
Purazuma, Kaku Yugo Gakkai-Shi, 77(2), p.146 - 152, 2001/02
no abstracts in English
Zhidkov, A. G.; Sasaki, Akira
Physics of Plasmas, 7(5), p.1341 - 1344, 2000/05
Times Cited Count：33 Percentile：68.53(Physics, Fluids & Plasmas)no abstracts in English
Zhidkov, A. G.; Sasaki, Akira; Tajima, Toshiki*
Review of Scientific Instruments, 71(2), p.931 - 934, 2000/02
Times Cited Count：9 Percentile：52.31(Instruments & Instrumentation)no abstracts in English
Sasaki, Akira
Reza Kenkyu, 27(6), p.430 - 434, 1999/06
no abstracts in English
Sasaki, Akira;
Purazuma, Kaku Yugo Gakkai-Shi, 75(5), p.507 - 508, 1999/05
no abstracts in English
Sasaki, Akira; ; Tajima, Toshiki*;
Computational Fluid Dynamics Journal, 8(1), p.142 - 148, 1999/04
no abstracts in English
Sasaki, Akira; ; Moribayashi, Kengo*; Tajima, Toshiki*;
Reza Kenkyu, 27(3), p.185 - 189, 1999/03
no abstracts in English
Kawachi, Tetsuya; ; Ando, Kozo*; Hara, Tamio*;
Inst. Phys. Conf. Ser., (159), p.211 - 214, 1999/00
no abstracts in English
Sasaki, Akira
Journal of Quantitative Spectroscopy & Radiative Transfer, 58(4-6), p.879 - 885, 1997/00
Times Cited Count：1 Percentile：10.30(Optics)no abstracts in English
Matsui, Ryutaro; Fukuda, Yuji; Kanasaki, Masato; Sakaki, Hironao; Iwata, Natsuyo*; Kondo, Kiminori; Kishimoto, Yasuaki*
no journal, ,
In the experiment conducted at JAEA-KPSI, we have observed an acceleration of background gas ions as a result of the interaction between a high peak power laser pulses and clustered media, where a few hundreds nanometer sized CO
clusters are embedded in a background H gas. In order to understand the acceleration mechanism of the background gas ions, we have carried out numerical simulations using the 2D PIC codes in the parameter regime relevant to the experiment. The simulation results shows that background gas ions are compressed and accelerated due to the Coulomb explosion of clusters. In addition, some ions are accelerated in the laser propagation direction due to the anisotropic electric field created by the relativistic effect.
Sasaki, Akira
no journal, ,
In the study of extreme ultraviolet (EUV) light sources, high conversion efficiency is achieved using the double pulse technique; a small tin droplet target is irradiated by the prepulse laser to cause fragmentation of the target to form a cloud small particles or mist, which is heated by the main CO
laser pulse to produce the uniform plasma from which efficient EUV emission is obtained. The fragmentation may be caused due to shock heating driven by the prepulse laser irradiation, which also may bring the target to the warm dense state. In this paper, a new hydrodynamics simulation, which will be used to calculate the temporal and spatial development of tin particles, is proposed. The simulation is based on the two dimensional self-adapting Lagrangian grid. The theory of liquid and gas phase transition in thermodynamic equilibrium, allows one to determine the ratio between gas and liquid phase at given temperature and density.
Matsui, Ryutaro; Fukuda, Yuji; Kawahito, Daiki*; Kishimoto, Yasuaki*
no journal, ,
In interactions between a high peak power laser pulses and clustered media, where CO clusters are embedded in a background H gas, as the resent experiment at JAEA-KPSI shows, the Coulomb explosion of clusters contributes to the acceleration of background gas ions. In order to understand the dynamics of the cluster expansion in the ambient gas, we have carried out numerical simulations using the 2D PIC codes in the parameter regime relevant to the experiment. The simulation results show that the charge separation and the electric field formation near the contact surface of a cluster and background gas play an important role in the structure formation of a cluster expansion.
