Vibrational relaxation rate constants for SF 6 from thermal lensing studies

Abstract

Previous work has shown that the decay of a thermal lens signal can be accurately described in terms of thermal conduction. The theoretical description of the risetime of the signal is tested by measuring the rate constants for vibrational relaxation of SF 6 molecules by the inert gases. The SF 6 is excited at 978.3 cm −1 and the measured rate constants at 330 K are 133 × 10 −15, 76 × 10 −15, 14 × 10 −15, 5.0 × 10 −15, and 740 × 10 −15 molecule −1 cm 3 s −1 for Ne, Ar, Kr, Xe and SF 6 quenching agent respectively. The rate constant for SF 6 quenching by Xe is also determined at 441.5 K as 7.2 × 10 −15 molecule −1 cm 3 s −1.