Sensitization of natural rhyolite rock using high gamma doses for thermoluminescence dosimetry

The current study presents rhyolite as a novel and promising natural thermoluminescence emission (TL) material. The work focused on enhancing the TL sensitivity of rhyolite via optimization of the processing conditions: annealing and pre-dose effect. The glow curves of irradiated rhyolite sample showed a single peak of about 110°C at 5°C sec^-1 heating rate. Sensitization was performed following Fleming's sensitization technique. It was found that applying 1 kGy pre-dose irradiation, followed by thermal activation at 550°C for 1 h, and cooling in air at room temperature were the optimum conditions for TL sensitivity improvement of this 110°C glow peak. Both nonsensitized and sensitized rhyolite have linear behaviour in the range 5-1500 Gy. The obtained results present rhyolite as a material for potential dosimetry applications.