Transitions to Optical Levels in the Argon L X-Ray Absorption Spectrum

Abstract

THE so-called fine structure of X-ray absorption edges is caused by the possibility of transition of an inner electron to different upper levels, these levels being more or less discrete for the lowest energies and approximately continuous for the higher ones. In the ordinary X-ray region, the fine structure observed with crystalline absorbers usually extends over more than 100 v. from the main edge. It was pointed out by Kronig¹ that in this case the discrete character of the upper states may be considered as due to the wave character of the motion of a free electron in the periodic field of the lattice. This conception has been successfully applied to many cases².