INTERPRETATION OF A RELATIVISTIC (E,2E) EXPERIMENT IN COPLANAR ASYMMETRIC GEOMETRY

Triply differential cross sections obtained in relativistic (e,2e) exp eriments on inner shell states in coplanar asymmetric geometries show a number of characteristic features, most notably a secondary maximum for emission of both electrons into the same quadrant. Referring to a recent experiment [K.-H. Besch, M. Sauter, and W. Nakel, J. Phys. B 30 , L73 (1997)] an interpretation of these findings in terms of destruct ive interference of the contributions to the S matrix describing excha nge of one longitudinal photon with those representing single transver se photon exchange is proposed. An additional feature of the triply di fferential cross section for backward emission of the slow electron ob served in this experiment is attributed to a double-scattering mechani sm.