Influence of the initial- and final-state configuration interaction on the anisotropy of the resonant Auger decay of Kr 3d−15pand Xe 4

Abstract

The anisotropy of the resonant Auger decay of photon-excited Kr 3d~i'~5~5p and Xe 4d3/Q 5i$6p states has been studied by the multiconfiguration Dirac-Fock method. The calculations account for the configuration interaction both in the initial and in the 6nal states of the Auger decay. For the nonresolved nd (n+ 2)p (J = 1) resonances (n = 3 for Kr, and n = 4 for Xe) the average intensities and the anisotropies of the Auger lines were calculated by weighing each partial rate by the pertinent Dirac-Fock photoexcitation probabilities. Our results show that, in addition to the initialand Gnal-state correlation, both the relaxation and the exchange interaction have a substantial effect on the anisotropy of these Auger spectra. For most Auger lines there is good agreement between our calculated P parameters and experimental values for the Kr and Xe nd i (n+ 2)p photoexcitation resonances; there is also satisfactory agreement for the Kr 3d~i'~5p and Xe 4d~i~6p resonant Auger spectra. However, the remaining notable discrepancies between theory and experiment indicate that important correlation effects are still omitted in our calculations. Discrepancies between difFerent experimental results stress the need for further improvements on the experimental side.PACS number(s): 32.80.Hd, 32.80.Fb

Recent Developments of Resonant Auger Transitions: Predictions and Propensity Rules for the Dynamic Spin Polarisation

“…Our results for the spin polarisation parameter ξ 2 for the experimentally observed peaks 1b and 3b of the resonantly excited Xe * (6p 3/2 ) N 5 O 2,3 O 2,3 Auger spectrum are shown in Table 9. While our data for the 1b peak are in good accordance to theoretical predictions by Hergehahn and Becker (1995) and by Tulkki et al . (1994), we obtain a much smaller average value of the spin polarisation parameter ξ 2 for the peak 3b.…”

Spin polarization transfer in the resonant Auger decay following Kr 3d 15p photoexcitation

“…The dominance of a SPW does not necessarily mean that other partial waves do not contribute at all. The value of the α 2 parameter calculated for this transition by only considering a f 7/2 wave is −0.505, which is larger than the MCDF and the experimental value of −0.375 (Kitajima et al 2001, Tulkki et al 1994, which clearly indicates the presence of other partial waves. A similar situation occurs also for line VI where the strongest transition in the group is that to the final state 2 P 3/2 for which the d 5/2 partial wave dominates.…”

“…Since the width of the resonances is larger than their separation, they strongly overlap and interfere when excited by a photon. Although one of them is excited 20 times more strongly than the other one (Tulkki et al 1994, Kitajima et al 2001, a proper account of their interference is important for the description of the angular distributions of resonant Auger electrons (Kitajima et al 2001) and their spin polarization. Modification of the formalism, as described above for the case of two overlapping resonances, is straightforward.…”

“…Briefly, both the initial and the final ionic state configuration interactions (FISCI) were taken into account. The initial resonances of a 3d −1 5p excitation are well described within a (non-relativistic) single-configuration approximation, including the three J = 1 levels of interest (Tulkki et al 1994). It is especially important to include FISCI, since the final states for the transitions considered contain three open subshells and therefore are strongly correlated.…”

Raman Regime Energy Dependence of Alignment and Orientation of KrIi States Populated by Resonant Auger Effect

“…The wide interest in the RA is largely based on the fact that the resonance population of the final ionic states is assumed to be considerably stronger than the direct nonresonant population. Therefore, it was expected that the dynamics of RA can be understood within a relatively simple two-step (or stepwise) model [3][4][5]. In this model, the direct population of the ionic states is neglected because it is forbidden in a single-electron dipole approximation and has a very small probability in comparison with the resonance channel.…”