Scintillation and thermoluminescence properties of Ce-doped Ca2Al2SiO7 single crystals

Abstract

Undoped and Ce-doped Ca2Al2SiO7 single crystals with different Ce concentrations were prepared by the floating zone method. From the X-ray diffraction patterns, we confirmed that all the grown crystals have no impurity phases. The undoped sample shows scintillation induced by X-rays, and the spectrum consists of two broad emission bands peaking at 350 and 400nm. The decay curve appeared to consist of only single exponential decay with the decay constant of 51ns. In contrast, Ce-doped samples show a broad scintillation peaking around 400nm, in which the decay curve consists of two exponential decay functions with the decay times of approximately 30 and 100ns. From the pulse height spectra measured using the present samples under 241Am 59.5keV γ-ray irradiation, we confirmed that the 0.3% Ce-doped sample exhibits the highest absolute scintillation light yield of 16,000ph/MeV. The samples also exhibit thermoluminescence (TL). The glow curves appear to have a broad feature with the peak temperature from 100 to 500°C for undoped and from 50 to 400°C for Ce-doped samples. Among the present samples, the 0.3% Ce-doped sample shows the highest sensitivity, and a linear response to the irradiation dose was confirmed in the dose range of 0.01–100mGy.