Neutron detection by a CR-39 detector and analysis of proton tracks etched in the same and opposite directions

A program code to simulate neutron interactions with a CR-39 detector and calculate parameters describing the induced etched proton tracks in the CR-39 material was previously developed. This code was used to understand the mechanisms involved during interactions with neutrons in the CR-39 material and the influence of the etching process, enabling an improvement in the efficiency of the CR-39 detector. Due to neutron interaction with atoms of the detector material, the created protons are emitted in different directions and their latent tracks are oriented randomly within the detector. The aim of this paper is to show differences between the number of visible tracks etched in the same and opposite directions from both sides of the detector. The efficiency of neutron detection was analysed as a function of the removed layer and neutron energy for both sides of detector. Previously developed Monte Carlo computer code has been used to calculate the efficiency of a CR-39-based fast neutron dosemeter. The results of this study show a significant contribution to the detection efficiency of CR-39 from tracks etched in the opposite direction on the back side of the detector (type 4) if both sides of the detector are etched simultaneously. The ratio between track densities on the back and front surfaces is related to the energy of monoenergetic neutrons, and this fact could be used for determination of their energy. This will be the subject of further work. (authors)