Stoß-Depolarisation angeregter Neon-Atome

Abstract

Variations of the number densities of excited Neon 2p ₄ and 3s ₂ levels were induced by interaction of a low pressure Ne or He-Ne discharge with the linearly polarized 633 nm light of a He-Ne gas laser. They are associated with partial alignment of those atoms having undergone a stimulated transition and consequently with anisotropy and polarization of the spontaneous radiation emitted by the discharge. From its gradual decrease at increasing pressure, depolarization cross sections ofQ ^*_Ne*−Ne =(157±12) Ų andQ ^*_Ne*−He =(63±7) Ų at mean relative velocity are derived. Comparison with values calculated by application of an adiabatic theory including sudden approximation yields good agreement in the case of Ne^*-He interaction and a discrepancy of 35% in the case of Ne^*-Ne interaction.