Collision broadening and molecular orbital X-rays. II

Abstract

For pt. I, see abstr. A13527 of 1974. The X-ray emission spectrum of an ion having an inner-shell vacancy moving through a solid is discussed using Weisskopf's theory of collision broadening (1933). In particular the approximations involved in a previous treatment which used the 'static' approximation are clarified. The analysis of the problem is illustrated by a direct evaluation of the emission spectrum of a model system by means of a numerical Fourier transform. The calculation demonstrates that the simpler static approximation is adequate except near the classical cut-off frequency where the dynamic variation of the molecular orbitals causes a broadening beyond this cut-off frequency. An estimate of this broadening is given.