Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Infrared laser multiple-photon dissociation of CTCl/sub 3/: Wavelength dependence, collisional effects, and tritium/deuterium isotope selectivity

Journal Article · · J. Chem. Phys.; (United States)
OSTI ID:6876918

Isotopically selective infrared multiple-photon dissociation of CTCl/sub 3/ in CDCl/sub 3/ was investigated using a pulsed CO/sub 2/ laser-pumped NH/sub 3/ laser in the 12 ..mu..m region. The wavelength dependence of CTCl/sub 3/ MPD in the ..nu../sub 4/ absorption band was studied and the observed MPD peak was found to be shifted approx.10 cm/sup -1/ to the red of the absorption peak at 835 cm/sup -1/, consistent with the anharmonicity of the CTCl/sub 3/ ..nu../sub 4/ mode. The CTCl/sub 3/ dissociation probability per pulse was investigated under various experimental conditions, including laser energy, pulse duration, and CDCl/sub 3/ and buffer gas pressure. A rate equation model was used to analyze the CTCl/sub 3/ experiments assuming various multiple-photon absorption and collisional relaxation mechanisms; this modeling effort was extended to a brief, more general, investigation of multiple-photon absorption by molecules with prespecified dissociation probability profiles. Lower limit single step T/D enrichment factors in chloroform MPD exceeding 15 000 were achieved under optimized conditions of the above parameters. No evidence of any CDCl/sub 3/ depletion or decomposition product was observed in irradiated 200 ppm CTCl/sub 3//CDCl/sub 3/ mixtures. CDCl/sub 3/ absorption measurements were made using an optically pumped NH/sub 3/ laser, and the observed high fluence T/D optical selectivity was found to be sufficiently high for practical tritium recovery.

Research Organization:
Department of Physics, University of California, Lawrence Livermore National Laboratory, Livermore, California 94550
OSTI ID:
6876918
Journal Information:
J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 81:5; ISSN JCPSA
Country of Publication:
United States
Language:
English