Thermoluminescence Kinetic Parameters of TLD-600 and TLD-700 after ²⁵² Cf Neutron+Gamma and ⁹⁰ Sr- ⁹⁰ Y Beta Radiations

Abstract

The thermoluminescent (TL) properties such as glow curve structure, relative thermoluminescence sensitivity, dose response linearity of lithium fluoride thermoluminescent dosimeters 6LiF:Ti,Mg (TLD-600) and 7LiF:Ti,Mg (TLD-700) are investigated after irradiation 252Cf neutron+gamma and 90Sr-90Y beta sources at room temperature and then the obtained results are compared. The kinetic parameters, namely the order of kinetics b, activation energy and the frequency factor s, are calculated using the computerized glow curve deconvolution (CGCD) program. The effect of heating rate on the glow curves of dosimeters is also investigated. The maximum TL peak intensities and the total area under the glow curves decrease with the increasing heating rate. There is no agreement with the kinetic parameters calculated by the CGCD program for both radiation sources.

Investigation of Thermal Quenching Effect for Lithium Fluoride (LiF) Type Dosimeters

“…However, thermal quenching was not observed in both TLD-600 and TLD-700 at 1000mGy and using ROI. When the results obtained for TLD-600 and TLD-700 in our study are compared directly with the study of İflazoğlu et al [18], thermal quenching was reported in İflazoğlu et al [18], but no thermal quenching in our study in the order of Gy. As a conclusion, the findings obtained in the above mentioned studies [15,[17][18] in the order of Gy do not seem compatible with those obtained in our study.…”

“…When the results obtained for TLD-600 and TLD-700 in our study are compared directly with the study of İflazoğlu et al [18], thermal quenching was reported in İflazoğlu et al [18], but no thermal quenching in our study in the order of Gy. As a conclusion, the findings obtained in the above mentioned studies [15,[17][18] in the order of Gy do not seem compatible with those obtained in our study. The Tmax values for the main dosimetric peak for both TLD-600 and TLD-700 were reported at ~245°C for the heating rate of 1°C/s in these studies of [15,[17][18].…”

“…TLD-700 showed thermal quenching according to the studies of [15,[17][18]. In our study, thermal quenching was observed only in the 10mGy over total area conditions for TLD-700.…”

“…The thermal quenching effect has been investigated by several researchers for TLD-700 [15,[17][18]. Pradhan [15] and [17] studied the influence of heating rates on various TLDs including TLD-700, for heating rates ranging from 1 to 50°C/s.…”

“…On the other hand, it was seen that the thermal quenching studies were quite limited for TLD-600 when the literature was reviewed. A recent study performed by İflazoglu et al [18] studied the thermal quenching for both TLD-600 and TLD-700 dosimeters. In this study, both dosimeters were irradiated with 15Gy and the variation in TL intensities was investigated considering the total area under the glow curve for heating rates ranging from 1 to 10°C/s.…”