Effect of Gamma Irradiation Doses on the Spectroscopic, Optical Dispersion, and Structural Properties of Cr-39 Nuclear Track Detector

The effect of gamma-ray irradiation doses (4, 6, 8, and 10 Mrad) on the structural and optical properties of the Cr-39 solid-sate nuclear track detector was studied before and after irradiation. The main characteristic amorphous X-ray peaks were observed with very slight changes in their intensity, confirming the structural stability of the Cr-39 solid-state nuclear track detector. The optical transmittance and absorbance of the irradiated sample are lower than that of the unirradiated sample in the UV region. The optical transmittance increases rapidly in the ultraviolet range (337-546 nm) until it reaches an almost constant value in the visible range. Moreover, a red shift in cutoff wavelength (λcutoff) was seen after irradiation, indicating that the fundamental absorption edge of the examined samples has decreased. Changes occurred in the optical band-gap values of all samples, with new groups of localized states generated near the valence and conduction band edges. The refractive index (n) values were observed to be increases after irradiation. The extinction coefficient increases with increasing wavelength as irradiated doses increase which is caused by surface plasmon absorption in irradiated samples.