Temperature dependence of BaF2 scintillation

The scintillation characteristics of BaF2 excited by γ-ray irradiation is studied as a function of temperature in the range −50-+27°C. We find evidence for three scintillation decay components with different temperature dependencies. A fast scintillation component with a decay time of ∼800 ps is independent of temperature, a slow component increases from 1 μs at +27°C to 5 μs at −50°C and a third slow component with a decay time of ∼0.4 μs 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°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 γ-rays.