ANGULAR-DISTRIBUTIONS OF SELECTED N-2 AUGER TRANSITIONS

The angular distribution of Auger electrons produced in the collision of 1634-eV electrons with N-2 is reported. The angular distributions a re measured relative to the internuclear axis of the molecule from 0 d egrees to 90 degrees in 6 degrees steps. When an Auger transition occu rs to an unstable doubly ionized state the molecular ion dissociates i nto two N+ fragments. Because the time required for dissociation of th e N-2(2+) ion is much less than that for rotation of the ion, the axia l recoil approximation holds to first order, and detecting one of the N+ ions determines the orientation of the target molecule at the time of the projectile-molecule collision. Therefore, a coincidence experim ent between the Auger electrons of appropriate energy and the N+ fragm ents is devised. The rotation of the N-2(2+) ions during the course of the dissociation process has been taken into account as a second-orde r approximation. As a result of this rotational effect, the predicted angular distribution function is smeared out by an amount depending on the different N-2(2+) final states. The data are analyzed in terms of a two-center model in which prolate spheroidal coordinates are used.