IR Laser Control of the Clustering of CF{sub 3}Br Molecules during the Gas-Dynamic Expansion of a CF{sub 3}Br/Ar Mixture: Bromine Isotope Selectivity

Journal Article · Wed Aug 15 04:00:00 EDT 2018 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776118070154· OSTI ID:22749755

Apatin, V. M.; Ogurok, N.-D. D.; Petin, A. N.; Ryabov, E. A. ^[1]

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1. Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

The infrared (IR) laser radiation control of the clustering of CF3Br molecules during the gas-dynamic expansion of a CF{sub 3}Br/Ar mixture at the exit from a nozzle is investigated. Prominence is given to studying the possibility of bromine-isotope-selective suppression of the clustering of CF{sub 3}Br molecules due to their resonance vibrational excitation in the gas-dynamic expansion zone near the nozzle. A continuous CO{sub 2} laser is used in experiments to excite molecules and clusters in a beam, and a quadrupole mass spectrometer is used to detect them. The experimental setup and the experimental technique are described. The dependences of the efficiency of molecule clustering suppression on the exciting laser radiation parameters, the gas parameters (composition, pressure) above the nozzle, and the distance from the nozzle exit section to a molecule irradiation zone are obtained. Bromine-isotope-selective suppression of molecule clustering is shown to occur at the exit from the nozzle due to the resonance vibrational excitation of gas-dynamically cooled CF{sub 3}Br molecules. When CF{sub 3}Br/Ar mixtures are used at pressure ratios p(CF{sub 3}Br): p(Ar) = 1: 10 and 1: 30, the enrichment of a cluster beam by bromine isotopes are K{sub enr}({sup 81}Br) ≈ 1.18 ± 0.09 and 1.12 ± 0.07 during the 9R(30) laser line (1084.635 cm{sup –1}) irradiation of a jet. The clustering suppression selectivity is α ≈ 1.18 when the mixture at the pressure ratio p(CF{sub 3}Br): p(Ar) = 1: 10 is used. These results suggest that the proposed method can selectively control the clustering of the molecules containing the heavy element isotopes that have a small isotope shift in IR absorption spectra (OsO{sub 4}, WF{sub 6}, UF{sub 6}).

• OSTI ID: 22749755
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 2 Vol. 127; ISSN JTPHES; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION SPECTRA
BROMINATED ALIPHATIC HYDROCARBONS
CARBON DIOXIDE LASERS
CLUSTER BEAMS
EXCITATION
INHIBITION
JET MODEL
LASER RADIATION
MIXTURES
MOLECULES
NOZZLES
SPECTRAL SHIFT
TUNGSTEN FLUORIDES
URANIUM HEXAFLUORIDE