A computer modeling study of isotopically selective, laser photodissociation of OCS in cryogenic solutions

Technical Report · Mon Dec 23 04:00:00 EST 1991

DOI:https://doi.org/10.2172/5730284· OSTI ID:5730284

Zittel, P F

Computer model calculations are presented for enrichments of carbon, oxygen, and sulfur isotopes by two-step, IR/UV, laser photodissociation of OCS in rare gas liquid solutions. The model calculations are based on previously measured fundamental physical properties, including spectroscopic parameters of the IR absorption bands of OCS in cryogenic solution, UV photodissociation cross sections for specific vibrational levels of OCS, and rates for vibrational relaxation of OCS by cryogenic solvents. Results are presented for both pulsed and continuous wave laser sources. Photodissociation through both the 2{nu}{sub 2} and {nu}{sub 1} intermediate vibrational levels of OCS is investigated. The laser characteristics required to obtain optimum enrichments are determined by modeling the dependence of enrichment on laser wavelength and intensity, as well as pulse width and timing for pulsed sources. Optimum carbon and oxygen isotope enrichment factors of 9--14 are found for two-step photodissociation through the OCS(2{nu}{sub 2}) vibrational level, using pulsed CO{sub 2} and KrF excimer laser sources. Optimum sulfur isotope enrichment factors of 5--6 are found for photodissociation through the OCS({nu}{sub 1}) level, using a pulsed 12 {mu}m laser and a KrF excimer laser. The enrichments found for continuous wave laser sources are smaller than those for pulsed sources. 19 figs., 4 tabs.

• Research Organization: Aerospace Corp., El Segundo, CA (United States). Engineering and Technology Group
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG03-87ER13657
• OSTI ID: 5730284
• Report Number(s): ATR-91(7171)2; ON: DE92009982
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE LASERS
CARBON OXYSULFIDE
CHEMICAL REACTIONS
COMPUTERIZED SIMULATION
DECOMPOSITION
ELEMENTS
ENERGY LEVELS
ENRICHMENT
EXCIMER LASERS
EXCITED STATES
GAS LASERS
IRRADIATION
KRYPTON FLUORIDE LASERS
LASERS
MULTI-PHOTON PROCESSES
NONMETALS
OXYGEN
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PULSED IRRADIATION
SIMULATION
SULFUR
SULFUR COMPOUNDS
VIBRATIONAL STATES