Thermoluminescent properties of Dy doped calcium borate based glass for dose measurement subjected to photon irradiation

Abstract

Abstract. This study presents the thermoluminescent (TL) dosimetric properties of calcium borate glass with various dopant concentration of dysprosium (Dy). Calcium borate glass is a new potential material to be used in radiation measurement with absorption coefficient that is close to human bone. A series of glasses based on chemical equation xCaO-(100-x) B2O3 system, x = 0.1, 0.2, 0.3, 0.4, 0.5 (0≤ x ≤100) ％ weight have been prepared by melt quenching method. The X-ray diffraction analysis of glass samples were carried out and the result showed a broad peak, which confirmed the amorphous nature of the glass. The 70B2O3-30CaO glass sample was found as the most stable among other glass samples studied. Present work focuses on 70B2O3-30CaO glass of (0.01-0.4) mol% Dy-doped in order to investigate the thermoluminescence (TL) properties, in particular, dose-response and fading. The glass samples were irradiated to dose range of 0.5-4.0 Gy subjected to 6MV photon irradiations of LINAC Primus MLC 3339. TL response of 0.3 mol% Dy-doped 70B2O3-30CaO glass was found to produce highest response, with good linear doseresponse relationship.

Evaluation of Bismuth Added HMO Glasses in Terms of Thermal, Mechanical, Gamma Radiation Shielding and Thermoluminescence Properties

“…Loss in TL signal over a period of time is known as fading and this mainly depends on the trap depth and the temperature at which the TLD materials are stored 38 . An ideal TLD must have low fading effect and this is possible when the traps are deep enough to trap the charges for a longer time, so that there is no recombination of charges 35 .…”

“…The knowledge of effective atomic number of a dosimeter is essential for its application in radiotherapy mainly because Z eff of the TLD material should match with that of human tissue (Z eff = 7.5) 35,38 while treating cancer or other diseases. For this purpose, the Z eff values of ZBiB-8 glass, calculated previously using Phy-X/PSD software were plotted with gamma energy in the range of 0.5-3 MeV in Figure 16.…”

“…This result indicated that this sample was not tissue equivalent and therefore, the deposition of gamma dose in human tissue must be corrected and calibrated. Meanwhile, it can also be noted that Z eff is not much far from that of human bone (Z eff = 13.8) 38 and therefore, can be used in the treatment of bone cancer.…”