Electronic Paramagnetic Resonance and Thermoluminescence of Polytetrafluoroethylene for Control of Radiation Technologies

The possibility of implementing the high-dose dosimetry method based on a combination of electron paramagnetic resonance (EPR) and thermally stimulated luminescence (TL) phenomena was investigated. Domestically produced polytetrafluoroethylene (PTFE) was used as an ionizing radiation detector. Detector samples were irradiated with accelerated electrons with an energy of 10 MeV with doses from 10 to 50 kGy. After irradiation, the intensities of the EPR and TL signals of each detector were measured. The dependence of the EPR signal intensity on the radiation dose was linear. The TL parameters were equal to: maximum temperature T = 164 °C, form factor u = 0,45, frequency factor S = 4,44·10 s, activation energy E = 1,14 eV. The spectral composition of TL had a wide band with a luminescence maximum of about 425 nm. The dose dependence of the TL output was also linear in the studied dose range. Annealing of EPR and TL signals occurred in the same temperature range, 160—240 °C. The correlation of dose dependences of normalized intensities of EPR and TL signals, the similarity of their temperature ranges of annealing intensities, indicated that the EPR and TL properties of PTFE detectors are associated with changes in the charge states of the same centers.