TY - JOUR

T1 - Static-field ionization model of He-like ions for diagnostics of light-field intensity

AU - Lötstedt, Erik

AU - Ciappina, Marcelo F.

AU - Yamanouchi, Kaoru

N1 - Publisher Copyright:
© 2020 American Physical Society.

PY - 2020/7

Y1 - 2020/7

N2 - We study static-field ionization of He-like ions with nuclear charge number in the range of 2≤Z≤36. Both the tunneling and over-the-barrier regimes are considered. We calculate the ionization rates by three approximate methods: a fitting formula based on the Perelemov-Popov-Terent'ev (PPT) formula, a perturbative expansion in powers of 1/Z, and a single-active electron approximation, and compare them with reference ionization rates computed by the multiconfiguration time-dependent Hartree-Fock (MCTDHF) approach. The relative deviation of the rates computed by the PPT-based fitting formula and the third-order perturbation theory from the rates computed by the MCTDHF approach is found to be around 10%. We discuss quantitatively the contribution from the exchange interaction during the ionization by comparing the single-active electron rates and the reference rates in which multielectron effects are included. We find that a single-active electron approximation, where the exchange interaction is neglected, results in the overestimation of the ionization rates by 30% for He and 2% for He-like Kr, showing that the magnitude of the effect of the exchange interaction scales approximately as 1/Z.

AB - We study static-field ionization of He-like ions with nuclear charge number in the range of 2≤Z≤36. Both the tunneling and over-the-barrier regimes are considered. We calculate the ionization rates by three approximate methods: a fitting formula based on the Perelemov-Popov-Terent'ev (PPT) formula, a perturbative expansion in powers of 1/Z, and a single-active electron approximation, and compare them with reference ionization rates computed by the multiconfiguration time-dependent Hartree-Fock (MCTDHF) approach. The relative deviation of the rates computed by the PPT-based fitting formula and the third-order perturbation theory from the rates computed by the MCTDHF approach is found to be around 10%. We discuss quantitatively the contribution from the exchange interaction during the ionization by comparing the single-active electron rates and the reference rates in which multielectron effects are included. We find that a single-active electron approximation, where the exchange interaction is neglected, results in the overestimation of the ionization rates by 30% for He and 2% for He-like Kr, showing that the magnitude of the effect of the exchange interaction scales approximately as 1/Z.

UR - http://www.scopus.com/inward/record.url?scp=85089277404&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.102.013112

DO - 10.1103/PhysRevA.102.013112

M3 - 文章

AN - SCOPUS:85089277404

SN - 2469-9926

VL - 102

JO - Physical Review A

JF - Physical Review A

IS - 1

M1 - 013112

ER -