Dosimetric properties of Tb-doped LiF/CaF₂ eutectic composite

Abstract

We have developed a LiF/CaF₂:Tb eutectic composite as a novel thermoluminescence (TL) dosimetric material. The LiF/CaF₂:Tb eutectic composite was obtained using a melt-solidification method with a lower melting temperature than that of LiF and CaF₂. The results of the PL emission and excitation spectra, the X-ray induced radioluminescence decay curve, and the TL emission spectrum indicate that the emissions of LiF/CaF₂:Tb eutectic composite are due to 4f-4f transitions of the Tb³⁺ ion. The integrated TL intensity of the LiF/CaF₂:Tb eutectic composite was 3.6 times higher than that of the commercial CaSO₄:Tm dosimetric material that is known to show a relatively high TL intensity. The dose response curve of the LiF/CaF₂:Tb eutectic composite was measured and the lower detection limit was 0.01 mGy which is the lowest value among the LiF/CaF₂ based composites.