Level-to-level vibrationally inelastic rate constants for Li2* –X (X=He, Ne, Ar, Xe) collisions

Abstract

We present 1088 level resolved rate constants for the vibrotationally inelastic collisions Li*2(vi=9, ji)+X →Li*2(vf, jf)+X with Li2 in the A 1∑+u state, ji =8, 22, and 42 and X=He, Ne, Ar, and Xe at T∼600 °C. At high ji, the results display a quasiresonant enhancement of vibrational transfer and a striking lack of dependence on target gas (X). At ji=42, the jf distributions for Δv≡vf−vi≠0 are quite narrow and peak at jf=ji+Δj with Δj=−4Δv. Internal energy conservation would require Δj=−6Δv; hence our use of the prefix ‘‘quasi’’ above. At high ji, the vibrationally inelastic cross sections are large: e.g., 4.5 Å2 into the single final level Δv=−1, jf =46 and over 80 Å2 total for Xe. Absolute errors as small as 6% have been routinely attained by using an analysis procedure which averages data from several fluorescence bands after correcting for variation of Franck–Condon factors with j.