Determination of the Bulk Etch Rate of the Nuclear Track Detector CR-39 Using Le-D Method

Abstract

The bulk etch rate (V_B) and the track etch rate (V_T) are an important parameters in identifying the track profiles and its growing rate. The aim of the paper is to determine the bulk etch rate of CR-39 detector using the track's diameter-length (Le-D) measurement method by irradiating the detector with different energies of alpha particles from the ²⁴¹Am source. A different normalities of the chemical solution NaOH at temperature (70±1) ^oC are used in etching the detectors to measure the track's lengths and diameters at different etching times corresponding to the energy of the incident particles and the etchant normality. The paper also aims to find the bulk etch rate by using the method of direct measurement of the removal layer thickness from the detector surface through alternating etching processes using normalities of (5.5-8) N. It is necessary to mention here the method is not needed to irradiate the detector with alpha particles. The bulk etch rate (V_B) of CR-39 detector found by Le-D method was (1.137-1.919) mm.hr^-1 at normalities (5.5-7.5). They showed good agreement with the values measured by the removal layer method which was (0.944-1.831) mm.hr^-1, and also they showed good agreement with other values resulted by Gruhn et al. paper for the same normalities. The V_B measured by Le-D method also showed good agreement with the fitting curve produced by fitting the experimental results of the both methods, which showed V_B between (1.0418-1.845) mm.hr^-1 for the same normalities, in addition to its good agreement with results of other studies with different methods.