Investigation on thermoluminescence property of Caspian seashore sand

We have shown that Caspian seashore sand has TL property and this is because of high quartz content of seashore sand. The sand was analyzed for constituents, found to have quartz (80%), magnetite (4%), and the rest were carbonate lithic, shells, minerals, igneous rocks. The elemental analysis using PIXE showed that the sand contain Si, Mg, Al, K, Ca, Ti, Cr. and Fe. We designed a TL Reader using an electric heater,a voltage regulator, a digital thermometer, and a PM tube connected to a PC equipped with analyzing software. By this instrument we measured the energy spectrum of the emitted light. The glow curves of natural and irradiated (10 Gy to 40 Gy) sand samples were obtained by a TL Reader showing emission peaks at 110 deg C, 260 deg C, 360 deg C and 550 deg C. The efficiency curve of the sand for TL emission showed that as irradiation increased, efficiency increased too but drops as irradiation increased further. This phenomenon may be due to destruction of crystal internal structure, capture of electrons by non-luminescent centers or decay of TL levels at room temperature. The glow curves of irradiated sand support this idea, since low temperature peaks have disappeared in highly irradiated samples. A HPGe detector measured the gamma-ray spectrum of the sand. It showed 1460 KeV of K-40 and several other gamma photo-peaks indicating presence of radioactive isotopes Tb-160 and Kr-85 and Pm-140 in the sand sample. The sand TL property can be used for incidental high dose release measurement from nuclear plants, and nuclear accident. (author)