Two-photon ionization of the K-shell of ions of the isonuclear sequence of a heavy atom

TL;DR

This paper theoretically predicts the two-photon K-shell ionization cross-sections of a heavy nickel ion sequence, highlighting giant resonances, quantum interference effects, and the importance of d-symmetry in the process.

Contribution

It provides detailed theoretical calculations of ionization cross-sections for a sequence of nickel ions, including effects of resonances and interference, using Hartree-Fock wave functions.

Findings

Giant resonances occur in the subthreshold ionization region.

Quantum interference significantly affects ionization probabilities.

d-symmetry of the final state dominates the cross-section in the hard X-ray range.

Abstract

The shape and absolute values of the generalized cross-sections of the two-photon resonant single ionization of the K-shell of ions of the isonuclear sequence of a heavy nickel atom (28Ni - Ni26+ - Ni24+ - Ni18+) have been theoretically predicted. The complete wave functions of ionization states have been obtained in the single-configuration Hartree-Fock approximation. The effects of the occurrence of giant resonances in the subthreshold region of the generalized ionization cross-section and destructive quantum interference of the amplitudes of the probability of radiation transitions have been established. The leading role of the d-symmetry of the final state of ionization in determining the total generalized crosssection in the energy region of absorbed photons in the hard X-ray range has also been established.