Atomic excitation and ionization as the result of inner-shell vacancy creation

Abstract

The probabilities of atomic excitation and ionization as the result of K‐shell and L‐subshell vacancy production have been calculated relativistically by the use of the Dirac–Fock–Slater wavefunctions in the sudden approximation. The results indicate that the ionization process is dominant for inner‐shell electrons, whereas the excitation process becomes important for outer shells. Comparison with other theoretical calculations and with the experimental data is made. Copyright © 1999 John Wiley & Sons, Ltd.

Effects of the molecular potential on coexcitations of valence electrons in the K -shell photoeffect of 3p and 4p elements

“…2) and deconvolved Kr [16]: The energy position and relative probability of the extracted resonances, and the shake-up and shake-off MEPE are shown in Table II. In spite of a simplified model including a modest number of channels, the result for the total shake probability in Ar (20%) agrees well with first-measured satellite intensities in high-resolution emission spectroscopy (∼30%) [12], the first theoretical calculations of double-photoexcitation cross section (∼18%) [43], as well as with other published data, including the latest emission-spectroscopy experiments [15,[44][45][46][47]: In these, it is necessary to take into account the standard normalization of excitation probabilities for the transitions to the single-excitation channel, leading to ∼10% higher values for shake-up and up to 50% for shake-off channels in this energy region.…”

Double-Electron Excitation Channels at the Ca2+ K-Edge of Hydrated Calcium Ion

“…In the past few decades, much experimental and theoretical effort has been made to determine the amplitudes and positions of multielectron excitation channels 1-17 and to calculate their relative cross sections. − The intensities of these excitations are usually very low, and an unambiguous identification of their energy position and shape is very difficult in solid samples, where the EXAFS oscillations are predominant. Nevertheless, the importance of accounting for double-excitation edges in the atomic background of condensed systems, to perform a reliable extraction of the structural signal, has been pointed out by several groups. − The neglect of multielectron excitations has been found to affect the EXAFS data analysis leading to errors in the determination of interatomic distances, first shell anharmonicity, and coordination numbers.…”

Study of vacancy decays in the L-shell photoionization of barium in the excitation energy range of 5.6–30 keV: from L2edge to energy high above the thresholds of double L-vacancy production

“…If we photoexcite Ba with energy higher than these thresholds, we may expect to observe the corresponding satellite or hypersatellite lines, although the majority of such multiple vacancy states relax via radiationless decays. According to the theoretical calculation for the shake probabilities based on the sudden approximation [57], the fraction of the [L 3 M 45 ] multiple vacancy states relative to the [L 3 ] single vacancy state is expected to be about 0.2%, and about 0.005% for the fraction of [L 3 L 3 ] double L-shell vacancy states relative to the [L 3 ] state, when we photoexcite the L shell electrons with 30 keV photons. Thus, extremely weak L x-ray hypersatellite lines are expected to be observed above the shakeoff thresholds.…”