Strong Increase in the Efficiency of Isotope-Selective Infrared Laser Dissociation of Molecules under Nonequilibrium Thermodynamic Conditions in a Shock Wave by Means of the Use of a Mixture with a Resonantly Absorbing Gas

摘要

A strong increase in the efficiency of isotope-selective infrared laser dissociation of molecules (by an example of CF2HCl) under nonequilibrium thermodynamic conditions in a shock wave has been reached by using a mixture with a resonantly absorbed gas (CF3Br). It has been shown that the dissociation yield of CF2HCl molecules irradiated in a mixture with CF3Br molecules is more than a factor of 5-10 higher than the dissociation yield in the case of their irradiation in the form of pure gas. The dissociation threshold of CF2HCl molecules in the mixture with CF3Br molecules also decreases significantly from approximate to 1.5-2.0 to 0.2-0.3 J/cm(2)). This allows the efficient isotope-selective infrared dissociation of molecules at low exciting energy densities (phi <= 1.0-1.5 J/cm(2)), as well and increasing the selectivity of the process. The method has been described and the first results have been presented. The dissociation of CF2HCl molecules selective in the Cl-35 and Cl-37 isotopes with the enrichment factor K-enr(Cl-35/Cl-37) = 0.90 +/- 0.05 is implemented when a CF2HCl/CF3Br = 1/1 mixture is irradiated by the 9R(30) (1084.635 cm(-1)) line of a CO2-laser at an energy density of phi approximate to 1.3 J/cm(2).