Thermoluminescence kinetic parameters of microwave chemically vapour-deposited diamond films at different gamma dose rates

Microwave chemically vapour-deposited (MWCVD) diamond films have been successfully used in dosimetric applications including radiotherapy and industrial dose assessments. The thermoluminescence (TL) properties and dose response, in a suitable MWCVD diamond film thermoluminescent dosimeter, should be independent of the irradiation dose rate used. Dose rate effects have been reported to exist, affecting the TL performance of polycrystalline CVD diamond. In the present work, dose rate effects on the TL kinetic parameters of two MWCVD diamond films of 6 and 12m thickness, exposed to 60Co gamma dose rates of 2.4, 5.94 and 13.1Gy/min, were investigated using a computerised glow curve deconvolution method. The TL glow curves featured a single TL peak at different dose rates, which were best fitted with a first-order kinetic curve having 2-3% figure of merit. No significant dose rate effects on the TL kinetic properties of the studied samples were observed.