DEVELOPMENT AND CHARACTERIZATION OF A BASO4-EU,P PHOSPHOR AS A HIGH-SENSITIVITY TL DOSIMETER

The BaSO4:Eu,P (0.5, 0.05 mol.%) thermoluminescent phosphor developed in this laboratory has a TL sensitivity about 5 times that of CaSO4:Dy (0.05 mol.%). The method of preparation was found to be quite importa nt for obtaining a sensitive TL phosphor with a dosimetric glow peak a t the desired temperature. Although the BaSO4:Eu,P (0.5, 0.05 mol.%) p hosphor is more sensitive, the BaSO4:Eu,P (0.5, 0.2 mol.%) which is ab out 2.8 times more sensitive than CaSO,:Dy (0.05 mol.%), gives the des ired glow peak structure. The gamma dose response of BaSO4: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 2.016 x 10(2) to 2.016 x 10(4) J.m(-2). TL emission spectra of BaSO4:E u and BaSO4:Eu,P show a broad emission peaking at 375 nm which is a ch aracteristic emission of Eu2+ corresponding to the P-6(7/2) --> S-8(7/ 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 BaSO4: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 at omic number.