Use of a bare CaF 2 (Eu) scintillator to assess the escape peak formalism and the fundamental parameter method

Escape peak and thick target yield formalisms are shown to be equivalent, although experimental results using a practical source–target–detector geometry favor the latter. A bare non‐hygroscopic CaF 2 (Eu) scintillator is used to measure the K X‐ray yield from thick targets of pure elements excited by monoenergetic photons. The scintillator is found free of dead layer up to the limit of 0.1 μm: it can thus detect photons above 2 keV energy with intrinsic efficiency approaching 100%.