Dependence of the Etch Rate Ratio on the Energy Loss in Proton Irradiated CR-39 Detectors and Recalculation of Etch Pit Parameters

Abstract

The neutron response of a nuclear etched track dosemeter can be calculated by simulating mathematically the generation of etchable tracks by neutron induced charged particles. The quantitative characterisation of track formation processes requires data on the bulk etch rate as well as the variation of the track etch rate along the particle trajectories. Evaluation of the experimental results obtained in a former study for proton tracks in CR-39 allowed determination of the fundamental relationship between the track etch rate and the restricted energy loss. The critical energy loss which forms the basic criterion on producing etchable tracks could be derived by extrapolation. Furthermore, time dependent track etch rates were recalculated for proton energies not available from experiments. The experimental data set could thus be completed by computed data. Furthermore, time dependent track lengths and diameters were recalculated. The comparison with track lengths and diameters experimentally determined represents a test on the quality of the data set and the computation method. Further evaluation of the time dependent track etch rates will allow the critical angle of incidence as a function of the proton energy and etching time to be derived. Using the time-dependent track parameters and etch rates as well as the critical values for the restricted energy loss and the angle of incidence the response of a neutron dosemeter can be calculated on the basis of a recently developed concept.