Research activity

There are two main fields of my scientific research activity. The first is a theoretical study of polarization and correlation phenomena in excitation and ionization of inner-atomic shells by beams of particles or photons followed by X-ray (fluorescence) and Auger (autoionization) electron emission.

One of the directions of investigation in this field is a study of photoexcitation or electron impact excitation of polarized atoms. Here a general formalism is created and a theoretical analysis of various experiments is done (with S.Baier A.G. Grum-Grzhimailo and V.V. Balashov). The formalism is applied for the analysis of the experimental data on magnetic dichroism in photoemission (in collaboration with B. Sonntag, Hamburg, FRG).

Another direction is a theoretical study of various types of coincidence measurements. A general formalism for the angular correlation studies in resonant double photoionization of atoms is suggested. A circular dichroism in photoelectron- Auger electron coincidence experiments is predicted (together with V.Schmidt, Freiburg, FRG). A theoretical analysis of another type of experiments, where a photoelectron and a polarized fluorescence photon are measured in coincidence, was done in collaboration with K.Ueda (Sendai, Japan). A theoretical basis for analysis of the correlations in cascade decay of core-excited atomic systems is developed, and a series of high-resolution experiments on Auger cascades in noble-gas atoms is analyzed (with K. Ueda et al., Sendai, Japan).

Finally very interesting problem of a complete experiment for Auger decay is studied together with U. Heinzmannn et al. (Bielefeld, FRG). Here new exact relations between the intrinsic Auger parameters have been discovered.

The second main field of my research work is a theoretical study of the interaction of energetic ion beams with solids and gas targets. In particular, a method based on the semiclassical approximation was suggested for calculations of the ionization cross sections, stopping power and energy loss straggling in collisions of atoms with ions carrying their own electrons.

At present an investigation of the molecular fragmentation in ion-molecular collisions is in progress in collaboration with the experimental group of H.Lutz (Bielefeld, FRG). Here an extention of the statistical energy deposition model is suggested which describes multiple ionization of atoms and molecules by ion impact. The model has been used successfully for interpretation of the orientation dependence of the yield of molecular fragments. Application of statistical methods to ion-impact fragmentation of fullerens is studied.