Improved scintillation proportionality and energy resolution of LaBr3:Ce at 80 K

Using highly monochromatic synchrotron X-rays in the energy range from 10.5 to 100 keV, the temperature dependence of the photon nonproportional response and energy resolution of LaBr3 scintillators doped with 5% Ce3+ were studied at 80, 295, and 450 K. Improvement of the proportionality and better energy resolution was observed on lowering the temperature. This effect suggests that the already outstanding energy resolution of LaBr3:Ce can be improved even further. It may also provide new clues to better understanding of the processes that cause nonproportionality of inorganic scintillator response.