Effect of 14 MeV neutrons on the optical properties of CR-39 detector

This study is carried out to establish a correlation between optical absorbance and track density in CR-39 detectors (a solid polymeric track detector whose composition is C12H18O7) exposed to different fluences of D-T (14 MeV) neutrons. This can be useful in estimating the neutron fluence and hence the dose without involving the tedious track counting procedure, especially when the track density is extremely high. Variation in the optical properties is studied using UV-VIS-NIR (ultraviolet-visible-near infrared) spectroscopic technique. The neutron-induced recoil tracks are developed by chemical etching and the track density is determined. The optical transmission spectra are obtained for pristine and neutron irradiated detectors before and after etching. A linear relationship is obtained between the track density and the optical absorbance with increasing neutron fluence. Another objective of this work is to study the effect of etching on the optical properties such as transmittance and absorbance of irradiated CR-39 detectors. The optical properties are found to be changing due to the development of tracks in the detector. (authors)