Electronic structure of atoms in laser plasmas: a Debye shielding approach

Abstract

Spectral properties of the low-lying singlet states of a helium atom and those of the low-lying doublet states of a lithium atom in laser plasmas are calculated using a quantum chemical configuration interaction method with a Debye shielding model Hamiltonian. A large spherical Gaussian basis set is adopted to describe the wavefunctions of electrons bound in a non-Coulombic Yukawa-type potential with high accuracy. The relative energies and the first ionization potential are found to decrease as the shielding parameter ? increases and the number of bound states to decrease gradually as ? increases. The oscillator strengths for the lowest dipole-allowed (2p)1P?(1s)1S transition of He and the second lowest (3p)2P?(2s)2S transitions of Li are shown to decrease as ? increases and the lowest (2p)2P?(2s)2S transition of Li to increase.