Recent developments in a neutron dosimetry system based on the chemical etch of CR-39

Abstract

A simple system which can be used to assess rapidly the area density of chemically etched pits is described. Studies of its application to neutron dosimetry using CR-39 have recently been extended. It has been shown that the previously reported fast neutron low energy threshold of 180 keV can be reduced to below 140 keV. Various boroncoated foils have been used to demonstrate that the system can also be used to measure thermal neutron exposure over a range exceeding seven decades. It would therefore form the ideal detection system for an albedo dosemeter. Two or three fast neutron sensitive CR-39 elements set back at an angle of about 35° together with a thermal neutron sensitive albedo element would constitute a personal neutron dosimetry system with energy and angular response close to the ideal.