Measurements of relaxation constants of orientation and alignment by method of stimulated photon echo in molecular gas

Abstract

The method of stimulated photon echo with specially chosen linear polarizations of the pumping pulses of coherent resonant radiation is applied for the investigation of collisional decay of orientation and alignment in the molecular gas SF 6 and its mixtures with buffers He and Xe. These relaxation rates are measured as a function of longitudinal velocities. Within the experiment accuracy, no remarkable velocity dependence of the depolarizing collisions rates was detected. This result confirms conventional approach of the depolarizing collisions theoretical treatment. In pure SF 6 the rates of elastic depolarizing collisions for orientation and alignment proved smaller than the known rate of velocity changing collisions. It means that only part of the elastic collisions participates in destroying of the level multipole moments.