Seminars Archive

A new method to study molecular Auger decay

Abstract
Coincidence study of photo- and Auger-electrons produced by photoionization of the K shell of fixed-in-space N2 molecules allows much deeper insight into the Auger decay process. From calculations of the photoelectron angular distributions it is known that at some angles predominantly 1sigmag or 1sigmau shell of N2 is contributing. By measuring the Auger electron angular distribution in coincidence with the photoelectrons collected at these particular angles, and in coincidence with atomic ions, one can separate the contributions of 1sigmag and 1sigmau shells to the Auger decay process without need to resolve these transitions in energy. As calculations show, the corresponding angular distributions are strongly different. Comparing experimental and theoretical angular distributions, one can identify transitions into different final molecular dicationic states. Important is that this method allows studying mainly the continuous part of the Auger spectrum which is hard to study by any other method. This continuum is formed by Auger transitions into repulsive doubly charged molecular ion states which do not create any resonance structure. On the other hand, the most intense resonant Auger transitions can also be studied by this method.