VIBRATIONAL PREDISSOCIATION OF UF6 CLUSTERS IN SUPERSONIC LAVAL NOZZLE-FLOW

The time-dependent change in the concentration of UF6 monomers populat ed in the ground state was monitored in a supersonic Laval nozzle how with an infrared diode-laser spectrometer in which the frequency of th e laser beam was fixed at the v = 1 <-- 0 transition (627.7 cm(-1)) of the nu(3) vibrational mode of the (UF6)-U-238 monomer. The concentrat ion of UF6 monomers in the ground state increased immediately after a single shot from a Raman laser tuned to a vibrational mode of UF6 clus ters (614.8 cm(-1)) was applied to the gas in the nozzle. Subsequently , this concentration leveled off and slowly returned to the previous l evel. These results indicate that the population of UF6 monomers in th e ground state increased as a result of the predissociation of UF6 clu sters vibrationally excited with Raman laser radiation. It is demonstr ated that one can utilize this procedure for vibrational predissociati on of UF6 clusters as a technique to increase the concentration of UF6 monomers in an irradiation zone for molecular laser isotope separatio n of uranium.