Optical-luminescence yield spectra produced by x-ray excitation

A general formula for the optical-luminescence yield spectra arising from the core excitation is derived, making use of a simple phenomenological model. In this model, it is assumed that various excitations from core electron levels give rise to an identical luminescence in the individual yields. A smaller yield of the inner-core 'electron excitation than that of the outer-core electron excitation results in a variety of anomalous yield spectra such as those with a negative jump, a positive jump with an inverted oscillation part, and an overtone oscillation. Effective thickness is introduced to explain the optical-luminescence yield spectrum of an opaque powdered specimen