AN EXPANSION METHOD FOR CALCULATING ATOMIC PROPERTIES. X. (1S2 SINGLET S)-(1s np SINGLET P) TRANSITIONS OF THE HELIUM SEQUENCE,
Abstract
The electric dipole matrix elements connecting the 1s2 singlet S and 1s np singlet P states of the helium isoelectronic sequence are calculated exactly to first order in inverse powers of the nuclear charge Z and the differences in the Hartree-Fock approximation are shown to correspond to virtual transitions of the 1s electrons. Comparison of the oscillator strengths predicted by a screening approximation with more accurate values reveals a regular variation in the error contained in the screening approximation, the correction of which allows the prediction of oscillator strengths and probabilities of 1s2 singlet S-1s np singlet P transitions for all values of n and all values of Z within a probable error of 2%. Values of the photoionization cross sections at the spectral heads are also presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1969
- Accession Number
- AD0691078
Entities
People
- A. Dalgarno
- E. M. Parkinson
Organizations
- Queen's University Belfast