Temperature dependence of scintillation responses in rare-earth-ions-doped LiCaAlF6 single crystals

We have tested high-temperature responses of prototype neutron detectors equipping Ce-doped lithium silicate glass (GS20), LiCaAlF6:Ce, LiCaAlF6:Eu, LiCaAlF6:Ce, Na, and LiCaAlF6:Eu, Na. These detectors were prepared by coupling of the scintillators to a photomultiplier tube (PMT) for high-temperature environments (R1288, Hamamatsu). In the pulse height spectra under thermal neutron irradiation in the temperature range from 25 °C to 150 °C, peak heights of all the samples decreased with increasing temperatures. The decreasing rates for the peak heights of LiCaAlF6 scintillators were lower than that of GS20. The LiCaAlF6scintillators can be used in the temperature range from 25 °C to 150 °C.