Modifications in the optical and thermal properties of a CR-39 polymeric detector induced by high doses of γ-radiation
| Autor: | Aya M. Nwara, S.A. Kandil, Mona H. Ibraheim, A.F. Saad |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Arrhenius equation Thermogravimetric analysis Radiation Materials science 010308 nuclear & particles physics Band gap Thermal decomposition Analytical chemistry Activation energy 01 natural sciences Absorbance chemistry.chemical_compound symbols.namesake chemistry 0103 physical sciences symbols Irradiation CR-39 |
| Zdroj: | Radiation Physics and Chemistry. 145:122-129 |
| ISSN: | 0969-806X |
| Popis: | Effects of γ-radiation on the optical and thermal properties of a poly allyl diglycol carbonate (PADC), a form of CR-39, polymer have been investigated. CR-39 detectors were exposed to γ-rays at very high doses ranging from 5.0 × 10 5 to 3.0 × 10 6 Gy. The induced changes were analyzed using ultraviolet-visible spectroscopy (UV–VIS) in absorbance mode, and thermogravimetric analysis (TGA). The UV–visible spectra of the virgin and γ-irradiated CR-39 polymer detectors displayed a significant decreasing trend in their optical energy band gaps for indirect transitions, whereas for the direct ones showed a little change. This drop in the energy band gap with increasing dose is discussed on the basis of the gamma irradiation induced modifications in the CR-39 polymeric detector. The TGA thermograms show that the weight loss rate increased with increase in dose, which may be due to the disordered system via scission followed by crosslinking in the irradiated polymer detector. The TGA thermograms also indicated that the CR-39 detector decomposed in three/four stages for the virgin and irradiated samples. The activation energy for thermal decomposition was determined using a type of Arrhenius equation based on the TGA experimental results. These experimental results so obtained can be well used in radiation dosimetry. |
| Databáze: | OpenAIRE |
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