Quenching and Depolarization of Resonance Radiation by Collisions with Molecules of a Foreign Gas

Abstract

A semi-classical theory describing the quenching and depolarization of resonance radiation by collisions with foreign gas molecules is presented. The total depolarizing probability is divided into two parts to allow for adiabatic and nonadiabatic depolarization. The equations for polarization are generalized in order to apply to the case in which the observed polarization results from several lines belonging to a hyperfine group. The effect of a magnetic field applied along the direction of observation is also included in the treatment. Experimental results on the polarization of the $\lambda 2537\mathrm{A}$ mercury line as a function of gas pressure and as a function of magnetic field at various fixed gas pressures show good agreement with the theory. Cross sections for quenching and depolarization have been calculated for the gases investigated and are presented in Table VI.