Temperature Dependent Scintillation and Luminescence Characteristics of GdI$_{3}$: Ce$^{3+}$

We investigated scintillation and luminescence properties of GdI$_{3}$:1% Ce $^{3+}$. It shows a light yield of 47 000 photons/MeV recorded with a Hamamatsu R1791 photomultiplier tube (PMT). Using an Advanced Photonix 630-70-73-510 avalanche photodiode (APD), the light output of this sample is 44 000 electron-hole pairs/MeV. The best energy resolution at 662 keV of 4.7% was recorded at 10$^{\circ}$ C with the APD with a shaping time of 0.5 $\mu$s. At room temperature (RT), the $\gamma$-scintillation decay curve of GdI $_{3}$:1% Ce$^{3+}$ shows a fast component of 45 ns, which is the same as the intrinsic Ce$^{3+}$ decay time, and that contributes 70% to the total light yield. GdI $_{3}$:1% Ce$^{3+}$ shows no afterglow at RT. Temperature dependence ranging from 80 to 600 K of X-ray excited emission spectra, pulse height spectra, scintillation decay curves and optically excited decay curves of Ce $^{3+}$ emission are also presented.