Scintillation light yield of BaF 2:Ce

Abstract

BaF 2:Ce scintillator is a well-known, reasonably fast and efficient scintillator characterized by a decent stopping power and availability of large size crystals. In this communication we report scintillation light yield measurements on a number of BaF 2:Ce samples cut from one larger boule. We interpret these measurements in a frame of a simple one-dimensional model developed and first tested on LuAP and LuYAP samples. The model is expected to reproduce the observed strong dependence of the effective scintillation light yield against the height of the sample. The fit to experimental points provides a value of the “intrinsic” light yield LY(0), as well as a value of the “loss” parameter μ (scattering and absorption of scintillation light in the sample). Although the value of the loss parameter μ, at around 0.5 cm −1, found from the fit for BaF 2:Ce is clearly lower than a typical value in LuAP and LuYAP, it is, nevertheless, much higher than the value of about 0.05–0.07 cm −1 measured in Delft for LaBr 3:Ce. We have also measured the absorption spectra of BaF 2:Ce crystals. The corrected spectra have been used to estimate contributions from scattering, self-absorption (by Ce-ions) and parasitic absorption from unidentified centers in order to establish physical limits imposed on the light yield from these crystals.