Collisional depolarization of excited114Cd 5s5p 3 P 1 atoms by collisions with molecular gases

Depolarization of excited¹¹⁴Cd 5s5p ³ P ₁ atoms induced by collisions with various molecular gases (N₂, H₂, D₂, CO, CO₂, CH₄, C₂H₆, C₂H₄) has been investigated using polarized fluorescence spectroscopy. After pulsed optical excitation of the Cd 5³ P ₁ level with appropriately polarized light the temporal behaviour of Zeeman quantum beats has been observed showing the influence of collisional destruction of orientation and alignment. By analyzing the signal curves at different molecular gas pressures the corresponding depolarization cross sections for¹¹⁴Cd atoms in the 5³ P ₁ state have been obtained. With regard to a test of a nuclear spin decoupling model for the collisions the cross sections were compared with previously measured hyperfine structure transfer cross sections of¹¹³Cd 5s5p ³ P ₁ atoms.