Transport Properties of a Gas of Diatomic Molecules. III. RDW Approximation to the Rotational Relaxation Time

Abstract

A quantum mechanical expression for the relaxation time is obtained for a low density gas of rotating diatomic molecules. The development is based on the restricted distorted wave approximation to rotationally inelastic scattering. The particular case of a gas of rigid spheres with embedded point dipoles is discussed. The classical limit of this result is also determined and agrees with the result obtained by another method.