Interference effects in alignment and orientation processes of atoms excited by polarized radiation

Abstract

The dynamics of the processes of alignment and orientation of atoms subjected to the action of polarized radiation has been studied theoretically in the energy range of excitation of autoionization resonances. The alignment parameters A20 for the 4p45p states of Kr II populated through the excitation and autoionization decay of Kr I 3d9np resonances depend on energy due to the interference between different resonance channels and the channel of direct photoionization. It is predicted that the orientation parameter O10 of some Kr II 4p45p states and the parameter of the angular distribution of photoelectrons βe1 strongly depend on energy. The absolute photoionization cross sections are calculated for the population of the Kr II 4p45p states in the case where the energy of excitation photons corresponds to the first four 3d9np resonances. A good agreement between the calculated and measured photoionization cross sections proves that it is important to take into account the interference between different resonance channels in order to appreciate the dynamics of the Auger decay of Kr I 3d9np resonances.