Kinetic theory of gas phase microwave experiments. II. The j=0 to j=1 transition in diatomics

The kinetic theory approach to gas phase microwave experiments, as presented in the previous paper, is further illustrated by treating the j=0 to j=1 transition in diamagnetic diatomics (or linear polyatomics) in some detail. The small dimensionality of this particular two level system allows a relatively exact treatment, i.e., within the restrictions imposed by being a two level system, and by the rotating wave approximation. Estimates of the relaxation times involved in such a system are given using the distorted wave Born approximation. General steady state and transient solutions to the system of moment equations are presented, which include the effects of unequal populations in the ’’m’’ states of the j=1 level. The physical nature of the ’’fourth moment’’ associated with this latter effect are emphasized throughout.