Photoionization of Kr near 4s threshold. II. Intermediate-coupling theory

Abstract

The Kr 4s-electron photoionization cross section as a function of the excitingphoton energy in the range between 30 eV and 90 eV was calculated using the configuration interaction (CI) technique in intermediate coupling. In the calculations the 4p spin-orbital interaction and corrections due to higher orders of perturbation theory (the so-called Coulomb interaction correlational decrease) were considered. Energies of Kr n states were calculated and agree with spectroscopic data within less than 10 meV. For some of the Kr 11 states new assignments were suggested on the basis of the largest component among the calculated CI wavefunctions.

Experimental and theoretical cross sections for photoionization of metastable Xe*. (6s 3 P 2, 3 P 0) atoms near threshold

“…As for the similar case of ground state Cs(6s) atoms a proper description of the photoionization dynamics of metastable Xe * atoms has to include -apart from the incorporation of the important correlation effects [18,19,[44][45][46] -relativistic effects in the calculation of the atomic orbitals (AOs).…”

“…The latter technique was used by us in previous work [44][45][46]. The ionization potentials of all Xe shells were calculated as the difference of the respective total atomic energies.…”

“…The ionization potentials of all Xe shells were calculated as the difference of the respective total atomic energies. The calculation of the correlational corrections IP CR (nl) were performed as described in [44][45][46]. Calculated IP(nl) values are compared with the measured ones [53,57] in Table 7 (IP(nl) for l / = 0 are statistically averaged).…”

“…In (17) l C (1) l 0 is the submatrix element of the spherical functions determined according to the standard system of phases [54] and is always positive, εl|d|n 0 l 0 is the [57,58], using conversion factor 1 eV = 8065.541 cm −1 d Correlational correction for IP(nl), see [44][45][46] radial integral determined either in length (d = r) or velocity form (d = d dr ∓ l max r ; l max = max(l, l 0 ) and the signs − or + correspond to the transitions l → l − 1, l → l + 1). We note that the formulae for the matrix elements of the correlation transitions in (16) have a rather bulky expression in general form and are not listed here.…”

Electron angular distributions of noble gases in sequential two-photon double ionization

“…In this context, Cooper-and correlative minima in the photoelectron partial cross sections are other important aspects regarding properties of the electronic structure and have been investigated for single-photon single ionization in the past [1]. Cooper-minima are known to arise from the decrease of the overlap integral of the bound and the continuum electronic state of the outgoing electron [24] whereas correlative minima are caused by the transition between correlation dominated photoelectron emission at lower energies and quasi-single electron emission at higher energies [25,26]. Reflections of these intensity variations along photon energy are also exhibited in the angular distribution of the photoelectron emission leading to a variation of the anisotropy parameter β.…”