Nikolai M. Kabachnik

Alignment following Au L3 photoionization by synchrotron radiation

The alignment of Au+ ions following L3 photoionization has been studied using a high-resolution x-ray spectrometer. We observed a small anisotropy for the angular dependence of Au Lι and Lα emissions. The alignment parameter derived from the experimental results is compared with theoretical calculations by Hartree–Fock approximation and random phase approximation with exchange. The contribution to the alignment of quadrupole interaction is discussed.

Angular anisotropy in the Auger decays of resonantly excited Kr 3d-15/25p and Xe 4d-15/26p states

The authors present theoretical calculations for the angular anisotropy parameter beta of the resonant Auger decays Kr 3d-15/25p (J=1) to 4p-25p and Xe 4d-15/26p(J=1) to 5p-26p. The transition amplitudes are obtained within a model treating the outer electron as a spectator. Its influence on the final states is taken into account via intermediate coupling MCDF calculations. This model reproduces the unusually large negative beta values observed in the considered transitions. Predictions are given for transitions not yet investigated experimentally.

Angular correlation patterns in double Auger decay

The angular distribution of two emitted electrons in the double Auger process in atoms has been theoretically investigated. In particular, the double Auger decay of a 1s vacancy in Ne and a 2p vacancy in Ar is considered. In analogy with double photoionization, we present a convenient parametrization of the angular correlation patterns for all possible angular momenta of the emitted electron pair. As a limiting case we investigate the angular correlations within the shake-off mechanism of the double Auger process. We also consider the influence of initial orientation of the vacancy on the electron angular distributions (circular dichroism).