Multiphoton absorption of 16 μm raman laser radiation in 238UF6

Measurements of multiphoton absorption of 16 μm Raman laser radiation in static UF6 (with 99.3% 238UF6) have been performed at room temperature and -35degC. The laser fluence has been varied between 10 and 300 mJ/cm2 for six laser frequencies in the range from 615 to 629 cm-1. Laser frequency and fluence dependence of energy absorbed by UF6 molecules have been investigated. The results indicate that the number of photons absorbed per molecule η(φ-bar) at a mean fluence φ-bar at several frequencies is in proportion to φ-barα where α≅ 2/3. (author)