Orientation and alignment of photoionized atoms

V. D. Ovsyannikov

Heinz W. Hermann, Ingolf Volker Hertel

James A. R. Samson, Anthony F. Starace

A N Grum-Grzhimailo, S. Fritzsche, Patrick O’Keeffe +1 more

In the present work it is shown that in atomic photoionization the Fano-like behaviour of vector correlation parameters in the region of an isolated autoionizing resonance possesses two universal values: the width and the energy shift with respect to the energy of the autoionizing state. This property is confirmed by fluorescence polarimetry studies, which provide, in the particular case of Xe 4d−15/26p (J = 1) photoexcitation, the experimental determination of the alignment and the orientation of the final photoion across the resonance. 1.

Philip George Burke

H. R. Sadeghpour, Chris H. Greene

Semianalytic methods are developed to predict the alignment and orientation of excited helium ions produced in the photoionization of neutral helium in the low-energy limit. The ionic electron probability distribution is shown to align itself orthogonal to the direction of the incident light polarization axis in the same manner as the photoelectron angular distribution [C.H. Greene, Phys. Rev. Lett. 44, 869 (1980)]. In certain instances, propensity rules for the alignment and orientation of the ionic electron are violated. Coherent contributions from different degenerate orbital angular momenta are seen to be partially responsible for these ``unfavored'' trends. Explicit predictions of the time-unresolved fluorescence polarization are presented, including the effects of fine-structure depolarization.