Effect of Ultraviolet Radiation on CN-85 and CR-39 Detectors by UV-Visible Spectroscopy and (He-Ne) Laser Penetration Techniques

Abstract

Nuclear track detectors (NTDs) are affected by particulate and non-particulate radiations. However, the effect of ultraviolet radiatio, (as an electromagnetic non particulate) radiation was determined by changes in spectroscopic and optical parameters of irradiated nuclear track detectors. Nuclear track detectors, namely CR-39 and CN-85 were UV-irradiated at a fixed distance using a stable Pen ray UV lamp emitting wavelength (l) at 254 nm. UV-visible spectroscopy was used to elucidate the effect at varying UV-exposure time (T_uv) (30-180 min). For measuring the optical changes of UV-irradiated nuclear track detectors, variations in penetration rate - P and laser penetration factor-F_P of He–Ne laser beam was used. The maximum absorbance (A) at wavelengths 234 nm (A₂₃₄) and 260 nm (A₂₆₀) was greater in CN-85 in comparison to CR-39. This coincides with (P) and (FP) of laser penetration. Furthermore, a linear relationship between absorbance A₂₃₄ and A₂₆₀ with UV-exposure time (T_uv) was detected in both detectors. Howoever, a polynomial relationship between laser penetration factor (F_p) and UV-exposure time (T_uv) was also observed. It could, therefore, be concluded that both detectors are suitable for UV-dosimetry at dose range applied in this study. Hence, the case of the technique may prove practical in some environmental and medical applications.