Schemes and Parameters of the Resonance Two-Photon Excitation of Vibrational States 2ν₃ in UF₆ Molecules by Bichromatic IR Laser Radiation

Abstract

Based on spectroscopic data for the overtone states of the ν₃ vibration in UF₆ molecules and lasing frequency of CF₄- and para-H₂-lasers, which emit near 16 μm, the possibility of resonance two-photon isotope-selective excitation of 2ν₃ vibrational states in UF₆ molecules by bichromatic IR radiation from these lasers has been analyzed. Schemes and parameters for the excitation of ²³⁸UF₆ and ²³⁵UF₆ molecules in the 2ν₃ state by two lasers with lasing frequencies detuned by 3.5–13.0 cm^–1 from the Q branches in the linear absorption spectra of UF₆ molecules in a gasdynamically cooled molecular flow are suggested. At the same time, the sum of these frequencies (ν_L1 + ν_L2) is equal to the frequency of the 0ν₃ → 2ν₃ vibrational transition in UF₆ molecules. If both lasers act on molecules simultaneously, there appears the possibility of their selective excitation from the ground vibrational state 0ν₃ to excited states 2ν₃. The isotope-selective excitation of overtone vibrational states 2ν₃ in ²³⁸UF₆ and ²³⁵UF₆ molecules using the method suggested here may form a basis for low-energy laser separation of uranium isotopes.