Thermoluminescence characterization of the irradiated minerals extracted from nopal

The mineral fraction from dehydrated nopal leaves (Opuntia ficus indica) belonging to the Cactaceae family was extracted and selected by sizes of 10 and 74 μm and exposed to 60Co gamma radiation at different doses in the range 70 Gy–20 kGy. The glow-curves from these polyminerals show a thermoluminescence (TL) band with one very intense peak at a temperature around 150 °C and a second one emerging in the high temperature region, moving in a large zone of temperature values according to the preparation used and the level of irradiation. The XRD analysis shows a composition of both biominerals as whewellite and weddellite and a mineral fraction as anorthoclase and quartz. The main TL characteristics of the polymineral content of the nopal was analyzed, i.e. the TL response at different doses and fading during storage at room temperature. The activation energy of the traps responsible for the TL emission was also investigated and a possible continuous distribution of traps is discussed. A review of the scientific literature shows that this is the first time that a TL study on nopal ionized by irradiation has been carried out.