OPTIMIZATIONS OF THERMOLUMINESCENCE RESPONSE OF DYPROSIUM DOPED LITHIUM MAGNESIUM BORATE DOSIMETER SUBJECTRED TO COBALT-60 GAMMA RAY

Abstract

There are a number of thermoluminescence (TL) materials have been investigated for its capability to be used as radiation dosimeter. These TL materials should be affordable cost and good reproducibility compared to available personal dosimeters nowadays. One of the TL materials that can be considered is using glass compound. In this study lithium as the modifier in magnesium borate glasses with the present of dysprosium as the activator was investigated to be performed as TL dosimeter. In this work, preliminary studied was carried out to determine the optimum time temperature profile (TTP) setting and annealing procedure as well as determination of optimum dysprosium concentration of the TLD. Lithium magnesium borate glass systems of (70-y) B2O3 - 20 Li2O – 10 MgO - (y) Dy2O3 with 0.05 mol% ≤ y ≤ 0.7 mol% were prepared by melt-quenching technique. The amorphous structure of the TLD was determine by using powder X-ray diffraction (XRD) analysis and the TL measurements were carried out using Harshaw 4500 TLD reader. The TLD reader was setup at 5 °Cs-1 of heating rate for the readout process. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. 200 C and 60 minutes of annealing temperature and annealing time respectively were applied for the annealing process of the samples. Optimum TL intensity was recorded with a heating rate of 5 Cs1. The highest TL responses and sensitivity were found for the sample with 0.1 mol% of Dy concentration.