TL characteristics of Ce3+-doped NaLi2PO4 TLD phosphor

Ce3+-doped NaLi2PO4 orthophosphate (with different impurity concentrations, i.e., 0.01-0.3 mol%) was prepared by a solid state reaction method. Formation of the material was confirmed using powder X-ray diffraction analysis. TL intensity was found to be the highest for the material having impurity concentration 0.2 mol% after annealing it at around 600 K for 1 h and subsequently quenching to room temperature. A typical glow curve consists of three peaks at around 454, 493 and 570 K (dosimetry peak). Good sensitivity (∼8 times more than that of TLD-100), low fading (∼15 % in 2 months), low-Z material (Zeff ≈ 10.8), very wide dose response (i.e., 0.1 Gy-1.0 kGy of γ rays) make the material a 'good' thermoluminescent dosimeter (TLD) phosphor suitable for personnel, medical and environmental dosimetry of high-energy radiation using TL. It could also be used during cancer therapy and sterilization of food where high doses are needed to be monitored. (author)