Rikagaku Kenkyusho

Sumitomo Electric Industries, Limited

Shin-etsu Chemical Co., Ltd.

Doryokuro Kakunenryo Kaihatsu Jigyodan

Shohei Isomura

Shigeyoshi Arai

Kyoko Sugita

Ryohei Nakane

Masami Shimizu

Koichi Okita

Eiji Kamijo

Tatsuya Nishimoto

Hayato Kaetsu

Takao Oshima

Tatsuhiko Honguu

Masatsugu Kamioka

Yo-ichi Ishikawa

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

Disclosed is a multi-stage hydrogen water isotopic exchange column suitable for use in producing heavy water. It comprises, at each stage, an overlying vapor-and-water contact bed, an underlying catalyst bed and means for collecting the water dripping from the overlying contact bed and guiding to and sprinkling the water on the upper-surface of the vapor-and-water contact bed of the lower adjacent stage. The vapor-and-water contact bed consists of a closely compacted fine network structure, and the water dripping from an overlying contact bed is transferred through the catalyst bed via water channel and is sprinkled over the upper-surface of the vapor-and-water contact bed of the lower adjacent stage. With this arrangement a multi-stage exchange column according to this invention is guaranteed little amount of gas pressure loss and elimination of water splashing which otherwise would be caused by increasing the flow rate of hydrogen gas.

Multi-stage hydrogen water isotopic exchange column

A catalyst for concentrating hydrogen isotopes for use in performing hydrogen isotopes exchange between gaseous hydrogen and liquid water, the catalyst comprising a support of porous polytetrafluoroethylene having a total specific surface area of 2 to 80 m.sup.2 /g as a result of mixing therewith 0.5 to 15% by weight of fluorocarbon or a porous styrene polymer or styrene/divinylbenzene copolymer having a specific surface area of at least 150 m.sup.2 /g, and deposited on the support particles of at least one element selected from Group VIII of the Periodic Table. A method for producing a support of porous polytetrafluoroethylene for such catalyst is also disclosed.

Catalyst for concentrating hydrogen isotopes and process for producing a

Growing community of inventors

Tokyo, Japan

Shohei Isomura