Spectral and Dosimetric Characteristics of Eu-Doped X-Ray Phosphors

Abstract

A spectral study (steady state and time-resolved photoluminescence (PhL) and radioluminescence (RL)) of Eu-doped phosphors in different host lattices (BaFCl, Sr3(PO4)2, Y2O2S, Y2O3) was carried out. Bright mono-band and fine-structure line emission in the blue-green and orange-red regions was recorded in the PhL and RL for all phosphors tested. The spectral patterns, decay curves and life-times observed in both PhL and RL were basically the same for all phosphors. From these observations the conclusion is that similar luminescent species are involved in the PhL and RL processes. Analysis of spectral and kinetic characteristics showed that the mono-species of Eu2+ and Eu3+ and their clusters are responsible for PhL and RL of the phosphors studies. Time-resolved measurements of RL induced by high energy (4 Mev) electrons were carried out for BaFCl:Eu and Y2O3:Eu. For these two phosphors the dependence of the RL intensity on the dose rate was also obtained. Good proportionality between RL intensity and dose rate in the region of a few tens of MGy.s-1 was revealed. This permits one to consider these phosphors as materials suitable for luminescence dosimetry for high energy and high dose rate conditions.