LuAG:Pr, LuAG:Pr,Mo and LuYAG:Pr relative light yield measured at wide temperature range with MPPC readout

Abstract Relative changes of light yield were investigated for LuAG:Pr, LuAG:Pr,Mo and LuYAG:Pr as a function of sample temperature. The measurements were performed using a dedicated cryostat filled with liquid nitrogen allowing for controlling the temperature of the samples between 90 K and 425 K. Scintillation light was detected by an MPPC photodetector, which was installed on a copper frame separated from the crystal and the cooling rod. Light yields as a function of temperature were investigated by irradiation of the crystals with 662 keV gamma-rays from a 137 Cs source. The temperature dependences were recorded using a short ( 1 μ s ) and long ( 10 μ s ) shaping time constants in the spectroscopy amplifier to study the changes in the intensity of fast and slow scintillation components. In addition, the ratio of light yield measured with short and long shaping time was calculated, providing some information on the balance between fast and slow decay modes in the tested scintillators.