Cerium-Doped ${\rm Cs}_{2}{\rm NaGdCl}_{6}$ Scintillator for X-Ray and $\gamma$ -Ray

New single crystals of Ce-doped Cs₂NaGdCl₆ are investigated under x-ray and γ-ray excitation. These scintillation crystals are grown by two zone vertical Bridgman technique and belong to elpasolite crystal family. Energy resolution, scintillation light yield, non-proportionality, energy resolution as a function of γ-rays energies and scintillation decay time measurements are presented. Ce³⁺-related x-ray excited emission is observed between 360 and 450 nm wavelength region at room temperature. At higher Ce-concentration both self-trapped exciton (STE) and Gd³⁺ emissions are disappeared and enhance Ce³⁺ emission. Under 662 keV γ-rays excitation, Cs₂NaGdCl₆ shows an energy resolution of 5.2%, (FWHM) at 1% Ce-concentration. Best energy resolution of 4.8% (FWHM) is obtained for 10% Ce-concentration. No significant improvement is observed in the energy resolution of Cs₂NaGdCl₆ with the increase of Ce-concentration. The highest light yield of about 21,000 ph/MeV is obtained for 10% Ce-doped crystal. At room temperature three decay time components are found under γ-ray excitation for all Ce-doped samples. This material is highly hygroscopic.