Ion-pair production and the effect of laser excitation in Li-Na collisions

Abstract
A beam-gas method is used to measure cross sections, Q, for ion-pair production in collisions of Li-Na and Li-Na* in a projectile energy range from 1000 to 5500 eV. The Na*, which represents Na in the 3p2P3/2 resonance state, is generated with a laser. For the same relative kinetic energy of the reactants, the Q for producing a given set of ionic products is larger for Li-Na* than for Li-Na collisions. Qualitative explanations are given which show why laser excitation of Na is responsible for this.