JOPSS - Search Results

Journal Articles

Development of a full spatial coherent X-ray laser at 13.9 nm and its applications

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 $_{3}$ and clarified a change of the microstructure near the Curie temperature.

Journal Articles

Development of a laser-pumped X-ray laser with full spatial coherence

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

http://ci.nii.ac.jp/naid/110003827831

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.

Journal Articles

X-ray laser beam with diffraction-limited divergence generated with two gain media

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

https://doi.org/10.1364/OL.28.001680

Times Cited Count：64 Percentile：90.06(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.

JAEA Reports

None

*; *

JNC TJ7400 2000-007, 222 Pages, 2000/03

JNC-TJ7400-2000-007.pdf:13.09MB

no abstracts in English

JAEA Reports

Investigation on sealing technique in geological disposal

Furuichi, Mitsuaki*; Toida, Masaru*; Masumoto, Kazuhiko*

JNC TJ8400 2000-021, 196 Pages, 2000/02

JNC-TJ8400-2000-021.pdf:23.23MB

For the geological disposal of high level radioactive wastes, after placement of tbe wastes, it is necessary to close off (to be called "sealing" hereafter) the underground potential passages (disposal pits, disposal tunnels, main and connecting tunnels and access tunnels) with an effective combination of engineered barriers such as buffers, backfilling materials, plugs and grout. It is necessary to ensure the long-term durability to isolate disposed wastes in the system. The results of the research works this year are as follows; (1)The objectives are to discuss the design of tunnel sealing experiments at URL site. The results of research were about (a)tracer experiment and numerical analysis (b)evaporation measurement (c)presentation at the coordination meeting (2)The discussion was about the equipment of inclined compaction methods and bearing capacity of rock against pressures for the concrete plugs.

JAEA Reports

Investigation on sealing technique in geological disposal

Toida, Masaru*; Masumoto, Kazuhiko*; *; Okutsu, Kazuo*; *

JNC TJ8400 2000-020, 68 Pages, 2000/02

JNC-TJ8400-2000-020.pdf:9.45MB

For the geological disposal of high level radioactive wastes, after placement of the wastes, it is necessary to close off (to be called "sealing" hereafter) the underground potential passages (disposal pits, disposal tunnels, main and connecting tunnels and access tunnels) with an effective combination of engineered barriers such as buffers, backfiling materials, plugs and grout. It is necessary to ensure the long-term durability to isolate disposed wastes in the system. The results of the research works this year are as follows ; (1)The objectives are to discuss the design of tunnel sealing experiments at URL site. The results of research were about (a)tracer experiment and numerical analysis (b)evaporation measurement (c)presentation at the coordination meeting. (2)The discussion was about the equipment of inclined compaction methods and bearing capacity of rock against pressures for the concrete plugs.

JAEA Reports