D. P. Gupta
The UV-Visible absorption spectra of CR-39 polymer, unirradiated and irradiated to gamma radiation up to 500 kGy dose were studied. The development of new peaks, shifting of absorption bands and their broadening as a result of gamma irradiation were observed and analyzed. The values of optical constant like direct and indirect band gaps have been determined. The values of indirect band gap have been found to have lower values then the corresponding values of direct band gap. The increase in carbon conjugation length and size of carbon clusters has also been pointed out from the results of UV-Visible spectroscopy.