Investigation of thermoluminescence properties of calcite mineral conducted by bacterial calcium carbonate (CaCO3) precipitation in organic soil

The object of this study is investigation of thermoluminescence (TL) properties which are dose response, heating rate, reproducibility and fading of calcite mineral conducted by bacterial calcium carbonate (CaCO3) precipitation in organic soil. The TL glow curves of the irradiated samples by using beta source 90Sr-90Y (≈ 0.04 Gy/s) were obtained for different dose levels between 2.4 Gy and 6.9 kGy. Trap parameters such as trap depth (Ea) and kinetic order (b) were obtained by using computerized glow curve deconvolution (CGCD) method, also the peak integral (n) was evaluated from TL signal by choose a specific dose at with 1oC/s heating rate β. The results for calcite show a clear TL glow curve with four main peaks located around 90, 140, 210 and 240 oC and good TL properties with good reproducibility, wide linear dose response and good fading. A good linearity behavior observed for the dose–response between 140 Gy and 2.3 kGy for the peaks 210 oC and 240 oC. The dosimetric peaks located between 200 and 250 oC are not affected by the storage time. The kinetic parameters of traps are calculated for two main peaks which located around 88 and 208 oC, the trap depth varies between 0.74 - 0.82 eV and 0.83 - 0.88 eV, kinetic order (b) varies between 1.24 -1.5 and 1.4 -1.5, respectively.