Influence of Coherence on Associative Ionization inNa(3p)+Na(3p)Collisions

Abstract
We have investigated the associative ionization of Na atoms in two counterpropagating thermal beams independently excited by various combinations of linearly and circularly polarized light. In this way information about coherence contributions to the ion signal has been obtained for the first time. These contributions which correspond to off-diagonal elements of the detection matrix have hitherto been neglected, but are of the same magnitude as the cross sections themselves and depend on the velocity.