DEPENDENCE OF THE ETCH RATE RATIO ON THE ENERGY-LOSS IN PROTON-IRRADIATED CR-39 DETECTORS AND RECALCULATION OF ETCH PIT PARAMETERS

The neutron response of a nuclear etched track dosemeter can be calcul ated 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 we ll as the variation of the track etch rate along the particle trajecto ries. Evaluation of the experimental results obtained in a former stud y for proton tracks in CR-39 allowed determination of the fundamental relationship between the track etch rate and the restricted energy los s. The critical energy loss which forms the basic criterion on produci ng etchable tracks could be derived by extrapolation. Furthermore, tim e dependent track etch rates were recalculated for proton energies not available from experiments. The experimental data set could thus be c ompleted by computed data. Furthermore, time dependent track lengths a nd diameters were recalculated. The comparison with track lengths and diameters experimentally determined represents a test on the quality o f the data set and the computation method. Further evaluation of the t ime dependent track etch rates will allow the critical angle of incide nce 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 t he critical values for the restricted energy loss and the angle of inc idence the response of a neutron dosemeter can be calculated on the ba sis of a recently developed concept.