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

Abstract

This study is carried out to establish a correlation between optical absorbance and track density in CR-39 detectors 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.

Measurement of neutron spectra generated from bombardment of 4 to 24 MeV protons on a thick 9Be target and estimation of neutron yields

“…21,22,24,26,27 Studies have also been carried out for estimation of dose responses of CR-39 detector in neutron fields by measuring the linear energy transfer (LET) spectra 28 and also by correlating with the optical properties. 29 A comprehensive literature survey on the 9 Be (p,n) reaction reveals that the first quantitative estimation of neutron yields from this projectile target combination has been reported in the early 1950s 30 using a thin beryllium target with projectile energies from threshold to 4 MeV. Since then several experiments were carried out with protons to study the neutron yield and angular distributions with different target thickness at various projectile energies using mainly time of flight measurements.…”