Development and Characterisation of a BaSO4:Eu,P Phosphor as a High Sensitive TL Dosemeter

Abstract

The BaSO 4 :Eu,P (0.5, 0.05 mol.%) thermoluminescent phosphor developed in this laboratory has a TL sensitivity about 5 times that of CaSO 4 :Dy (0.05 mol.%). The method of preparation was found to be quite important for obtaining a sensitive TL phosphor with a dosimetric glow peak at the desired temperature. Although the BaSO 4 :Eu,P (0.5, 0.05 mol.%) phosphor is more sensitive, the BaSO 4 :Eu,P (0.5, 0.2 mol.%) which is about 2.8 times more sensitive than CaSO 4 :Dy (0.05 mol.%), gives the desired glow peak structure. The gamma dose response of BaS0 4 :Eu,P (0.5, 0.2 mol.%) was found to be linear in the gamma dose range 0.1 to 10 Gy. The TL response to UV exposure was sub-linear in the exposure range 2.016x10 2 to 2.016 x10 4 J.m -2 . TL emission spectra of BaSO 4 :Eu and BaSO 4 :Eu,P show a broad emission peaking at 375 nm which is a characteristic emission of Eu 2+ corresponding to the 6 P7/2 → 8 S7/2 transition. The phosphor shows about 5% post-irradiation fading in 30 days. This sensitive TL phosphor can find potential applications in personnel and environmental radiation dosimetry, whereas BaSO 4 :Eu,P (0.5, 0.05 mol.%) phosphor can find an application as an X ray storage phosphor due to its high TL sensitivity coupled with high effective atomic number.