Efficiency of electron-hole pair production in scintillators

Phenomenological models for electron-hole pair production in scintillators are reviewed. All models provide similar results when compared on the basis of consistent definitions. The assumption of constant loss parameter K is untenable. The loss parameter K(E) was calculated from first principles by employing a dielectric response function derived from the Callaway model. The rapid variation of K(E) suggests replacement of K by an effective threshold displacement, Delta E, which is appreciable for semiconductors but negligible for insulators. The prediction of high conversion efficiency, beta congruent to 1.0, implies low transfer efficiency, S < 1, in most insulators.