Thermoluminescence studies of calcium metaborate (CaB2O4) nanocrystals synthesized by solution combustion method

This paper presents the thermoluminescence properties of calcium metaborate (CaB2O4) nanocrystals prepared by solution combustion method. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and thermoluminescence (TL) analysis respectively. The XRD patterns showed the orthorhombic structure with the crystallite size at around 27 nm and the FESEM micrograph revealed the formation of nanocrystals with irregular spherical shape. Weight fraction obtained from EDX analysis consequently led to determination of an effective atomic number. It was found that the effective atomic number of CaB2O4, Zeff = 14.1 was equivalent to the effective atomic number of the bone, Zeff = 13.2 with error of 6.8 %. The samples were annealed using the TLD oven and exposed to Cobalt-60 source. TL glow curves were recorded using a Harshaw model 3500 TLD reader. The TL glow curve of this material showed a simple, single, peak located at around 150 °C. The most striking dosimetric feature of these nanocrystals was the excellence of the linearity response of a dose range from 1 Gy up to 100 Gy with R2= 0.9827 compared to the TLD-100 powder with R2= 0.9276. The high linear correlation between dose and TL response to gamma radiation suggests that calcium metaborate nanocrystals can be considered as a promising material to be used in thermoluminescence dosimetry

Thermoluminescence properties of CaO-B2O3 glass system doped with GeO2

The aim of this study is to investigate the thermoluminescence properties of germanium doped calcium borate glass for thermoluminescence dosimeter used. Glasses with composition (30-x) CaO-70B2O3: xGeO2 where x=0.1, 0.2, 0.3, 0.4 and 0.5mol% were prepared using a melt-quenching method. The glasses were irradiated to 60Co gamma ray with doses ranging from 0.5Gy to 4.0Gy. The amorphous phases were identified for all glass samples. The glow curves were analyzed to determine various characterizations of a thermoluminescence dosimeter of the glass. It was found that the sample with a concentration of 0.1mol% GeO2 has the best thermoluminescence characteristics such as linearity, sensitivity, fading characteristic, minimum detectable dose and effective atomic number. The results clearly showed that germanium doped calcium borate glass has a potential to be considered as the thermoluminescence dosimeter

Thermoluminescence energy response of germanium doped calcium borate glasses using theoretical calculation

This is a theoretical study about the energy response of germanium doped calcium borate glass subjected to photon irradiation in the energy range of 20 keV to 20 MeV. It has been observed that germanium doped calcium borate glass has higher TL response at incidence photon energies below 150 keV. However, the relative TL response decrease as the incident photon energy increases and the relative responses are almost constant in the energy range 150 keV to 10 MeV. The result of this study will be helpful in order to get information on the energy response of germanium doped calcium borate glass to photon irradiation as this material can be used as radiation dosimeter