Investigation of temperature dependence of inorganic scintillators using the HYPERSCINT research platform

The temperature dependence of four inorganic scintillation detectors was examined spectrally using the HYPERSCINT Research Platform 200. The detectors were subject to 6 MV photon irradiations from a linear accelerator, varying only the temperature of the detectors. Optical fibre connectorisation was characterised and found to be essential to the repeatability of measurements. The magnitude of the temperature effect on each detector was evaluated by calculating the percentage change in total photon counts for a range of temperatures. Gd₂O₂S:Tb and Gd₂O₂S:Eu exhibited the lowest change in counts with temperature, 0.12%/°C and −0.10%/°C, respectively, with ZnS:Ag showing the highest change in counts of −0.55%/°C. Gd₂O₂S:Pr photon counts changed by −0.25%/°C. All the scintillators demonstrated linearity when the change in photon counts with temperature in the full-width at half maximum of their spectrum are integrated. Establishing the magnitude of the temperature dependence of the materials is critical to decide whether correction factors are required. This is especially true in applications such as brachytherapy, where detectors equilibrise to body temperature.