Role of Non-Radiative Transitions in X-RAY Analysis

Abstract

Radiative and non-radiative transitions present alternative ways for the excited atom to reduce its energy when the initial state is an atom singly ionised in one of its inner electron shells. Since the fluorescence yield gives the probability that the empty state in the inner (sub)shell is filled in by a radiative process, it seems that the generated x-ray intensities are independent of the non-radiative rearrangements from the point on where the value of fluorescence yield is given for the (sub)shell in question. In that way the intensity of an x-ray line would solely be dependent on the ionisation probability of the given (sub)shell and on the rates of the radiative transitions (determining the relative intensities of the lines originating from the same subshell). That image involves that the non-radiative processes only influence the value of the fluorescence yield. For the simplest case i.e. for the K shell it is true.