A new high sensitivity Na2LiPO4:Eu OSL phosphor

Abstract

A new high sensitivity Na₂LiPO₄:Eu optically stimulated luminescence dosimeter (OSLD) material was prepared by a simple solid-state diffusion method. The formation of the material was confirmed by comparing the experimental data with that available in the literature (JCPDF # 80-2110). The dosimetric properties of the phosphor material using a continuous wave-optically stimulated luminescence (CW-OSL) technique were studied. The material was studied for different concentrations of the impurity and also for different heating treatments. The material doped with 1.0 mol% and annealed at 873 K was found to be the most sensitive. The phosphor was found to have all the good dosimetric characteristics, such as tissue equivalence (low-Z, Z_eff ∼ 10.8), high sensitivity (∼3 times less than the commercially available Al₂O₃:C, Landauer Inc., USA and BeO, Thermalox® 995, Materion Inc., USA), low fading (∼6.2% in 40 days), wide range of dose response (0.1–1.0 kGy), excellent reusability, easy optical bleaching (annealing) for its reuse, etc., which makes the material useful for dosimetry of high-energy radiations using OSL. The advantages of our OSLD phosphor are the easily available and inexpensive ingredients and a very simple method of preparation that makes it cost effective as compared to the commercially available OSLD phosphors. Also, it is easy to handle, unlike the Thermalox® 995 (BeO) dosimeters which are very toxic, and require a special method of preparation and handling.