Properties of CaSO4(Mn) Powder for Thermoluminescence Dosimeter

Abstract

Thermoluminescence and electron paramagnetic resonance (EPR) of CaSO4(Mn) powder have been studied. The intensities of the hyperfine lines in the EPR spectra of Mn++ and the heights of the thermoluminescence glow peak are found to change in parallel, upon varying the conditions of heat treatment and the concentration of Mn++. It is also found that Mn++ present in aggregate state, which gives a broad EPR spectrum, is not an effective activator for thermoluminescence; heat treatment at high temperatures serves to disperse this aggregated Mn++, which increases the thermoluminescence sensitivity. The relation between the thermoluminescence intensity and the radiation dose is linear, so long as the duration of irradiation is within certain limits; the deviation from the linear relation is explained in terms of fading of thermoluminescence at the temperature of irradiation. © Taylor & Francis Group, LLC.