Item

Abstract

So-called perfect or complete scattering experiments in atomic and molcular physics habe extensively been carried out applying polarized interacting particels and/or coincidence techniques in order to detect the resulting particels. The description of scattering amplitudes and their relevant phases can be referred to Ben Bedersons's (New York) initial papers at the end of the sixties and beginning of the seventies. In his analysis of theoretical and experimental data, Fano's work of 1957 resulted already in a physical picture, which related scattering amplitudes to state multipoles of excited atoms, e. g. orientation and alignment.
The article starts with Perfect Scattering Experiments in atomic collusions, including special topics in the areas of electronic, ionic atomic collisions, and photoionization processes. These expamples of special topics do not restrict the striking enourmous consequences for the advancement of physics as initially introduced by Ben Bederson.
Angle Spin resolved experiments ant theory, and their analysis will be discussed with a particular emphasis on electron emission processes. This will be illustrated for the resonantly excited Auges decay of argon atoms. For the generation of the intermediate excited Rydberg state two different mechanisms , photoexcitation and electron impact excitation, will be considered.
Main ideas of complete experiments for the Auger decay are presented together with selected results obtained in this comparatively new field of research.
In a subsequent chapter, a selection of fundamental achievements connected to perfect scattering processes within molecules have been described.