Abstract
This work describes the thermoluminescence (TL) response of silica-based materials irradiated with thermal neutrons. These materials have the compositions (mol %) (60 + x) SiO2-(30-x)Na2O-5MgO-5Al(2)O(3),where x = 0, 5, 10 and 15. The irradiation was carried out in the fluence range 1 x 10(14) -1 x 10(17) neutron cm(-2). These glassy materials gave two TL glow peaks at around 473 and 643 K. The intensity ratio of these peaks is found to vary with varying SiO2/Na2O ratios. The peak at 473K is more prominent at the ratio SiO2/Na2O = 75/15, while the intensity of the other one at 643K increases by decreasing the value of this ratio. The former peak is attributed to both 'AlO4' hole centres and non-bridging oxygen (NBO) ion centres induced by neutrons irradiation, while the latter one could be ascribed to (NBO) ion centres introduced by the network modifiers, Na+ ions. The TL response against the neutron beam fluences of the material having the ratio SiO2/Na2O = 75/15 is found to show sublinearity in the above-mentioned range of fluence (using the area under the curve method). The other features such as high sensitivity and simple glow curve structure might be good indicators for this material to be used as a dosimeter in several applications such as thermal neutrons or in food irradiation.