Dosimetric properties of rare earth doped LiCaBO3 thermoluminescence phosphors

Lithium Calcium borate (LiCaBO3) polycrystalline thermoluminescence (TL) phosphor doped with rare earth (RE3+) elements has been synthesized by high temperature solid state diffusion reaction. The reaction has produced a very stable crystalline LiCaBO3:RE3+ phosphors. Among these RE3+ doped phosphors thulium doped material showed maximum TL sensitivity with favorable glow curve shape. TL glow curve of gamma irradiated LiCaBO3:Tm3+ samples had shown two major well-separated glow peaks at 230 and 430 °C. The glow peak at 430 °C is almost thrice the intensity of the glow peak at 230 °C. The TL sensitivity of the phosphor to gamma radiation was about eight times that of TLD-100 (LiF). Photoluminescence and TL emission spectra showed the characteristic Tm3+ peaks. TL response to gamma radiation dose was linear up to 103 Gy. Post-irradiation TL fading on storage in room temperature and elevated temperatures was studied in LiCaBO3:Tm3+ phosphor.