Rikagaku Kenkyusho

Other

Shin-etsu Chemical Co., Ltd.

Nippon Steel Corporation

Nippon Steel Chemical Co., Ltd.

Taiyo Nippon Sanso Corporation

Shigeyoshi Arai

Kyoko Sugita

Hayato Kaetsu

Shohei Isomura

Masashi Hashimoto

Hiroshi Kawakami

Takeshi Ishii

Shigeru Hayashida

Koichi Chiba

Hitoshi Kihara

Naoya Hamada

Takashi Kambe

Maki Sato

Takao Oshima

Yoshiharu Horita

Takashi Otsubo

Yuji Fujioka

Makoto Yamasaki

Tatsuhiko Honguu

Takumi Kono

Tomozumi Murata

Hironori Ohba

Syohei Isomura

Tetsuro Majima

Takemasa Shibata

Masatsugu Kamioka

Yo-ichi Ishikawa

Akio Ohya

The method for concentrating an oxygen isotope or isotopes of the present invention combines the step of concentratingO and/or the step of depletingO that utilizes photodissociation of ozone by a laser beam with an oxygen distillation step that concentrates the oxygen isotope. At this time, it is preferable to carry out a step of isotope scrambling in addition to the above. When both a step of concentratingO and a step of depletingO are carried out, whichever thereof may be done first prior to the other. Also these steps may be placed either before or after the oxygen distillation step. Moreover, at least one of said oxygen distillation step, the concentratingO step, the depletingO step and the isotope scrambling step is preferably carried out twice or more.

Method for concentrating oxygen isotope or isotopes

A method for laser-assisted separation and enrichment of silicon isotopes such as Si, Si and Si on the basis of infrared multiple-photon dissociation of silicon halides represented by Si F , wherein the silicon halides are irradiated synchronously with multiple infrared pulsed laser beams at different wavelengths.

Method for efficient laser isotope separation and enrichment of silicon

Method for enrichment of oxygen 18 with a laser

This invention relates to a process for enriching carbon 13 by mixing a halogenomethane containing one or more fluorine atoms and carbon 13 of natural isotopic abundance with one or two or more additive gases selected from a group of oxygen-containing oxidizing agents, halogens, and hydrogen halides, irradiating the resulting raw material gas mixture by a carbon dioxide laser to cause selective dissociation and reaction of the halogenomethane of carbon 13, separating the unchanged substances from the reaction mixture to obtain a product enriched with carbon 13, further converting the enriched product to carbon monoxide, and enriching carbon 13 by low-temperature distillation of the carbon monoxide. The process has advantages of low overall energy consumption, high yields of carbon 13, easy separability of the unchanged substances and high degrees of carbon 13 enrichment.

Process for enriching carbon 13

An enrichment method of carbon 13 by use of the multistage laser irradiation. A mixture of CHClF.sub.2 and Br.sub.2 is used as a start substance. The mixture is irradiated with laser rays emitted from a carbon dioxide gas laser to obtain CBr.sub.2 F.sub.2 enriched with carbon 13. This CBr.sub.2 F.sub.2 enriched with carbon 13 is once more irradiated with laser rays emitted from a carbon dioxide gas laser to produce C.sub.2 Br.sub.2 F.sub.4 which is further enriched with carbon 13. Alternatively, the product CBr.sub.2 F.sub.2 of the first laser irradiation is once more irradiated together with O.sub.2 to produce COF.sub.2 which is further enriched with carbon 13.

Method of enriching the isotope carbon 13 by means of laser irradiation

Silicon isotopes are effectively separated by irradiating a polysilane compound or a fluoromosilane compound according to this invention with infrared laser rays. The polysilane compound is defined by the formula.

Working substances used in laser isotope separation and method of laser

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Tokyo, Japan

Shigeyoshi Arai