Luminescence and dosimetric properties of CaF2:Ce,Dy phosphor

The synthesis of Ce and Dy doped CaF2 phosphor (CaF2:Ce,Dy) was performed by chemical reaction with calcium carbonate by using hydrofluoric acid in a stoichiometric ratio. At 0.40 and 0.40 mol% concentration of Ce and Dy respectively in the CaF2 matrix, the doped phosphor was highly sensitive in powder and pellet form. Morphological, crystallographic and optical characteristics were studied by low vacuum scanning electron microscopy, X-ray diffraction, and Raman and photoluminescence spectroscopies. Results show that this new phosphor is ten times more sensitive to gamma radiation than the well-known TLD-100. The linearity of the thermoluminescent response to gamma radiation was between 0.001-500 Gy, followed by a saturation region. Fading was negligible after two months storage. The repeatability of the pellets under the readout heating cycles was performed according to the standard recommendations. In addition, the kinetic parameters were determined by glow curve deconvolution. The results reported that this newly developed CaF2:Ce,Dy+PTFE phosphor offers high sensitivity at low doses, which is very useful in dosimetry.