Thermoluminescent characteristics of Actinolite-Teflon composites for gamma high-doses

In this work a preliminary study of the thermoluminescent (TL) dosimetric properties of the Brazilian actinolite:Ca2(Mg,Fe)5(Si8O22)(OH)2(silicate of the Jade family) was undertaken for gamma high-doses. Actinolite occurs in several regions in the world. In this work actinolite in the form of rude mineral from Governador Valadares, Minas Gerais, Brazil, was studied. The natural actinolite samples were powdered, and the selected grains were mixed with Teflon in the proportion 2(Teflon):1(Actinolite). The mixture was pressed and sintered for production of pellets of composites Actinolite-Teflon. The glow curves present two peaks at 125 C and 210 C. The TL response reproducibility presents a maximum variation coefficient of 4.8%. The calibration curve is linear between 0.5 Gy and 1 kGy for pellets irradiated with gamma radiation (60Co) and between 0.5 Gy and 10 Gy for pellets irradiated with X-rays (33 keV). The TL response presents an energy dependence of 26% for X-rays between 27 and 41 keV. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)