Conclusion and Outlook

Abstract

We discussed the general theory and numerical methods necessary for the calculation of angle and spin resolved Auger processes. In the second chapter, the theoretical formalism has been developed within the two-step model. Applying the framework of density matrices and state multipoles we investigated the primary ionization or excitation of an inner shell electron via electron or photon impact and discussed the subsequent Auger decay. The general equations of angular distribution and spin polarization have been derived and we discussed in detail which information can be obtained in such experiments using either electron or photon impact for the generation of the inner shell hole. Here, different polarization states of the electrons or photons have been considered where we stressed the physically important process of generation of spin polarization out of alignment. We have derived non-linear interrelations between the angular distribution and spin polarization parameters of the Auger decay. Resonant Auger transitions have been extensively discussed considering the cases of either linearly, circularly, or unpolarized light for the primary photoexcitation process. For concluding the theory we discussed some special cases of Auger transitions in more detail. Like spin polarization of isotopic multiplets, the angle dependent intensities and spin polarizations for specific intermediate ionic hole states, or the Auger emission from an unresolved intermediate fine structure state. Eventually, we considered relations for the asymmetry parameters of the Auger decay and for the linear dichroism of Auger emission.