Thermoluminescence dose-response characteristics of in-house produced nanocrystalline CaF2:Ce synthesized by the co-precipitation method for gamma dosimetry.

The thermoluminescent dose-response characteristics of nanocrystalline CaF2:Ce synthesized by the co-precipitation method were investigated under gamma irradiation using the integrated thermoluminescence signal. Structural characterization by X-ray diffraction confirmed the formation of a face-centered cubic phase with an average crystallite size of approximately 48 nm, while scanning electron microscopy revealed an irregular surface morphology. FTIR spectroscopy identified the characteristic Ca-F stretching vibration at 711 cm-1. Raman spectroscopy showed characteristic vibrational modes at 154, 283, 713, and 1088 cm-1 for pure CaF2, whereas the Ce-doped sample exhibited peaks at 281, 321, 455, and 1086 cm-1. The thermoluminescence response was evaluated over the gamma dose range of 0 - 20 mGy using a137Cs source. In addition, photon interaction parameters at 0.662 MeV yielded mass attenuation and mass energy-absorption coefficients of 0.069 and 0.028 cm2 g-1, respectively, with effective atomic numbers of 12.9 and 12.8 for photon interaction and energy absorption. The synthesized CaF2:Ce exhibited a measurable dose-dependent thermoluminescent response with good correlation between the absorbed gamma dose and the integrated TL intensity over the investigated dose range.