Doppler Profiles of the Distribution of O(¹D) Relaxing in Ne

Abstract

The relaxation of hot atoms in a gaseous moderator remains a fundamental problem in rarefied gas dynamics [1, 2]. The rate of relaxation of energetic particles to equilibrium has important applications in diverse fields. In addition to the calculation and measurement of relaxation times, in recent years there have been numerous measurements of the details of the relaxing velocity distribution functions by Doppler spectroscopy [3, 4]. For example, Park et al [5] have investigated the relaxation of H atoms produced in laser dissociation of H₂S at 193 nm. They measured the Doppler profiles of the H atoms at the Lyman-α line during the relaxation by collisions with the rare gases and some molecular moderators. Nan and Houston [6] monitered the velocity relaxation of S(¹D) by He, Ar and Xe by measuring the Doppler profile of S(¹D) created by pulsed laser photolysis of OCS at 222 nm. Cline et al [7] reported the relaxation of hot I(² P _1/2) that was produced from photodissociation of of n-C₃F₇I at 266 nm in a background of He.