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Itakura, Ryuji; Fushitani, Mizuho*; Hishikawa, Akiyoshi*; Sako, Tokuei*
AIP Conference Proceedings 1702, p.090021_1 - 090021_4, 2015/12
Times Cited Count：0 Percentile：0(Physics, Applied)We theoretically investigate coherent dynamics of ions created through ultrafast multichannel photoionization from a viewpoint of photoelectron-photoion correlation. The model calculation on single-photon ionization of Ar reveals that the coherent hole dynamics in Ar
associated with a superposition of the spin-orbit states 
(J = 3/2 and 1/2) can be identified by monitoring only the photoion created by a Fourier-transform limited extreme ultraviolet (EUV) pulse with the 9-fs pulse duration, while the coherence is lost by a chirped EUV pulse. It is demonstrated that by coincidence detection of the photoelectron and photoion the coherent hole dynamics can be extracted even in the case of ionization by a chirped EUV pulse with the sufficiently wide bandwidth.
Matsumoto, Taro; Kishimoto, Yasuaki; Miyato, Naoaki; Li, J.*
Journal of Plasma Physics, 72(6), p.1183 - 1187, 2006/12
Times Cited Count：6 Percentile：21.5(Physics, Fluids & Plasmas)no abstracts in English
Nishikino, Masaharu; Tanaka, Momoko; Kawazome, Hayato; Kawachi, Tetsuya; Sasaki, Akira; Hasegawa, Noboru; Ochi, Yoshihiro; Kishimoto, Maki; Nagashima, Keisuke; Onishi, Naofumi*
AIP Conference Proceedings 827, p.499 - 504, 2006/04
no abstracts in English
Sukegawa, Kota*; Kishimoto, Maki; Kado, Masataka
JAERI-Tech 2004-077, 21 Pages, 2005/01
JAERI-Tech-2004-077.pdf:4.17MB
no abstracts in English
Nishikino, Masaharu; Kawazome, Hayato; Tanaka, Momoko; Kishimoto, Maki; Hasegawa, Noboru; Ochi, Yoshihiro; Kawachi, Tetsuya; Nagashima, Keisuke
IPAP Conference Series 7 (Proceedings of 8th International Conference on X-ray Microscopy (XRM 2005)), p.423 - 425, 2005/00
no abstracts in English
Nagashima, Keisuke; Tanaka, Momoko; Nishikino, Masaharu; Kishimoto, Maki; Kado, Masataka; Kawachi, Tetsuya; Hasegawa, Noboru; Ochi, Yoshihiro; Sukegawa, Kota*; Tai, R.; et al.
Applied Physics B, 78(7), p.927 - 932, 2004/05
We have succeeded in developing a laser-pumped X-ray laser with full spatial coherence at 13.9 nm. A highly directed X-ray laser beam with the divergence of 0.2 mrad was generated from the double target experiment, where a seeding light from the first laser medium was amplified in the second medium. The observed divergence is close to the diffraction limit value within a factor of two. The seeding light was amplified in the second medium without refraction influence and the gain coefficient was about 8 cm-1. From the measurement of visibility, it was found that the spatial coherent length is longer than the beam diameter. As an application of this coherent X-ray laser, we observed a surface microstructure of ferroelectric material, BaTiO
and clarified a change of the microstructure near the Curie temperature.
Nagashima, Keisuke; Tanaka, Momoko; Nishikino, Masaharu; Kishimoto, Maki; Kado, Masataka; Kawachi, Tetsuya; Hasegawa, Noboru; Ochi, Yoshihiro; Sukegawa, Kota*; Tai, R.
Purazuma, Kaku Yugo Gakkai-Shi, 80(3), p.236 - 240, 2004/03
A laser-pumped X-ray laser with full spatial coherence has been developed for the first time. This X-ray laser has the wavelength of 13.9 nm and the beam divergence of 0.2 mrad. In the experiment, a seeding light from the first laser medium was amplified in the second medium, which worked as an active spatial filter. The observed beam divergence was close to the diffraction limited value within a factor of two. The seeding light was amplified in the second medium without refraction influence. The gain region of the second medium was far away from the target surface compared with that of the first medium and located in the considerably low density region. From the measurement of visibility, it was found that the spatial coherent length is longer than the beam diameter. It means that this X-ray laser beam is full spatial coherent.
Nagashima, Keisuke; Kado, Masataka; Nishikino, Masaharu
JAERI-Research 2003-035, 10 Pages, 2004/02
JAERI-Research-2003-035.pdf:0.52MB
no abstracts in English
Nishikino, Masaharu; Tanaka, Momoko; Nagashima, Keisuke; Kishimoto, Maki; Kado, Masataka; Kawachi, Tetsuya; Sukegawa, Kota*; Ochi, Yoshihiro; Hasegawa, Noboru; Kato, Yoshiaki
Physical Review A, 68(6), p.061802_1 - 061802_4, 2003/12
Times Cited Count：61 Percentile：89.37(Optics)We demonstrate a generation of highly coherent X-ray laser at 13.9 nm by oscillator-amplifier configuration with two targets. In the oscillator-amplifier configuration, the seeding X-ray laser beam from the first target is injected into the plasma amplifier at the second target. When the X-ray laser beam is not affected by refraction during propagation in the amplifier, the X-ray laser beam with small divergence and high coherence is generated. The observed X-ray laser beam has 0.2 mrad of the diffraction limited divergence and the full spatial coherence.
Tanaka, Momoko; Nishikino, Masaharu; Kawachi, Tetsuya; Hasegawa, Noboru; Kado, Masataka; Kishimoto, Maki; Nagashima, Keisuke; Kato, Yoshiaki
Optics Letters, 28(18), p.1680 - 1682, 2003/09
Times Cited Count：64 Percentile：90.08(Optics)We have demonstrated an x-ray laser at a wavelength of 13.9 nm with a beam divergence of 0.2 mrad, which is 1.8 times the diffraction limit. The x-ray laser is generated using two gain media, where the seed x-ray pulse from the first medium is amplified in the second medium. The effect of refraction on x-ray propagation is reduced by spatially and temporally controlling the injection of the seed x-ray to the second medium.
Tang, H.; Daido, Hiroyuki; Kishimoto, Maki; Sukegawa, Kota*; Tai, R.; Mesesson, S.*; Tanaka, Momoko; Lu, P.; Kawachi, Tetsuya; Nagashima, Keisuke; et al.
Japanese Journal of Applied Physics, 42(2A), p.443 - 448, 2003/02
Times Cited Count：14 Percentile：50.38(Physics, Applied)no abstracts in English
Machida, Masahiko; Koyama, Tomio*
Physica C, 378-381(Part1), p.443 - 447, 2002/12
no abstracts in English
materials synthesized by electrolysis on fused mixtures of MgCl, NaCl, KCl and MgBO
Yoshii, Kenji; Abe, Hideki*
Superconductor Science and Technology, 15(10), p.L25 - L27, 2002/10
Times Cited Count：11 Percentile：50.72(Physics, Applied)no abstracts in English
Nagashima, Keisuke; Kawachi, Tetsuya; Kado, Masataka; Tanaka, Momoko; Hasegawa, Noboru; Sukegawa, Kota*; Namba, Shinichi; Tang, H.; Daido, Hiroyuki; Kato, Yoshiaki
Purazuma, Kaku Yugo Gakkai-Shi, 78(3), p.248 - 255, 2002/03
no abstracts in English
Kato, Yoshiaki; Daido, Hiroyuki; Nagashima, Keisuke; Kawachi, Tetsuya; Hasegawa, Noboru; Tanaka, Momoko; Tang, H.; Tai, R.; Lu, P.; Kishimoto, Maki; et al.
AIP Conference Proceedings 641, p.31 - 39, 2002/00
no abstracts in English
Koike, Masato
Heisei 9nenndo - Heisei 12nenndo Kagaku Kennkyuhi Hojyokin, Kenkyu Seika Houkokusyo (Kenkyu Kadai Bangou 09309001), p.70 - 76, 2001/03
no abstracts in English
SrCaCuOy containing columnar defects*; Hanaguri, T.*; *; Maeda, A.*; Sasase, Masato; Hojo, Kiichi; Steel, D. G.*; Lee, J. U.*; Hofman, D. J.*
Physical Review B, 59(17), p.11568 - 11574, 1999/00
Times Cited Count：8 Percentile：45.66(Materials Science, Multidisciplinary)no abstracts in English
Hazama, Taira
PNC TN9410 98-073, 48 Pages, 1998/08
The theoretical formula for the statistical error estimation in Mihalczo method was derived, and the dependence of the error were investigated on the facility to be measured and on the parameter in the data analysis. The formula was derived based on the reactor noise theory and the error theory for the frequency analysis, and found that the error depends on such parameters as the prompt neutron decay constant, detector efficiencies, and the frequency bandwidth. Statistical errors estimated with the formula was compared with experimental values and verified to be reasonable. Through parameter surveys, it is found that there is a setting in the data analysis to optimize the magnitude and reliability of the errors. In the experiment performed in DCA subcriticality measurement facility, it is estimated experimentally that the measurement requires 20 minutes to obtain the statistic error of 1% for the keff 0.9. According to the error theory, this should be reduced to 3sec in the aqueous fuel system typical in fuel reprocessing plant.
PNC TN9410 98-013, 48 Pages, 1998/03
Thermal striping phenomena characterized by stationary random temperature fluctuation are observed in the region immediately above the core exit of liquid-metal-cooled fast breeder reactors (LMFBRs) due to the interactions of cold sodium flowing out of a control rod (C/R) assembly and hot sodium flowing out of adjacent fuel assemblies (F/As). Therefore the in-vessel components located in the core outlet region, such as upper core structure (UCS), flow guide tube, C/R upper guide tube, etc., must be protected against the stationary random thermal process which might induce high-cycle fatigue. In this study, frequency characteristics of stationary random temperature fluctuations were investigated by the use of the time-series data from parallel impinging jet experiments, TIFFSS-I. From the investigations, the following results have been obtained; [Auto-Power Spectral Density Functions] (1)Higher frequency componets were decreased drastically with the close to the test piece surface, due to the presence of filtering effect by the laminar sub-layer and heat tansfer to the surface from coolant. (2)Dependence to the nozzle velocities was observed at the outside and inside positions of the laminar sub-layer region. It was due to the increasing of turbulent intensities with increase of the nozzle velocities. [Coherence Functions] (1)Coherency between outer temperatures of the laminar sub-layer was very small. 0ne of the main reasons is that the outer temperatures of the laminar sub-1ayer were dominated by the stationary random phenomena of turbulence flows. (2)It was confirmed that the coherency between immediate positions of different thermocouples had relatively higher values. [Transfer Functions] (1)The dominant frequency band of the gain was about 3 - 10 Hz for the transfer functions of the outer position to the inner position of the laminar sub-layer, and of the inner position of the laminar sub-layer to the test piece surface. (2)There wasno dependence of ...
Journal of Nuclear Science and Technology, 19(7), p.543 - 554, 1982/00
Times Cited Count：7 Percentile：62.17(Nuclear Science & Technology)no abstracts in English
