Momentum dependence of generalised oscillator strengths of atomic K shells using the local plasma approximation

Abstract

Previously, the authors have calculated atomic generalised oscillator strengths at zero momentum transfer using the local plasma approximation. In this work, they have extended their calculations to non-zero momentum transfer for the atomic K shell. Basically, the authors have adopted similar formulations to those developed previously, however, parameters here were allowed to be momentum dependent. A pseudo-electron density distribution derived from the exact generalised oscillator strength data at zero momentum transfer was employed in the present work. This has several advantages over the Hartree-Slater electron density distribution employed previously. Calculated results of the generalised oscillator strengths at any momentum transfer and energy transfer for atoms up to sodium have been compared with theoretical data of the matrix element method. Fairly reasonable agreement was found for all cases.