Temperature dependence of BaF2 scintillation

The scintillation characteristics of BaF2 excited by gamma-ray irradiation is studied as a function of temperature in the range -50 - +27 degrees C. We find evidence for three scintillation decay components with different temperature dependencies. A fast scintillation component with a decay time of similar to 800 ps is independent of temperature, a slow component increases from 1 mu s at +27 degrees C to 5 mu s at -50 degrees C and a third slow component with a decay time of similar to 0.4 mu s becomes clearly visible at low temperatures. The scintillation light intensity of the fast component stays constant over the entire temperature range studied, whereas that of the slow component increases by a factor of two when cooling from room temperature to -25 degrees C. However, further cooling causes a decrease in the scintillation light intensity. The increased light output results in an improved energy resolution for low-energy gamma-rays.