Etching and optical properties of 1–2 MeV alpha particles irradiated CR-39 radiation detectors

Abstract

A comparison of track etch parameters at low energy alpha particles is presented, using the Lantrak and the Baryotrak CR-39 nuclear track detectors. Experimental data from literature, obtained through exposing CR-39 detectors at low energy alpha particles from a 241Am source and, subsequently, etching them in NaOH, KOH, and NaOH+ethyl alcohol aqueous solutions at 70°C and 80°C, have been numerically analyzed here. Radial etch rates of alpha particle etch pits have been determined, compared, and critically discussed for both CR-39 types. Ratios of alpha etch pit diameters and etch pit densities have also been examined as a function of etching time, showing no notable differences in the comparison between these two detectors. This study has been extended from the structural point of view by performing new Ultraviolet–visible (UV–Vis) and Raman spectroscopy measurements on non-irradiated, α-irradiated and α-irradiated/etched Lantrak and Baryotrak detectors. The direct band-gap energies have been determined and no significant differences have been observed in detectors subjected to different conditions. The Raman spectra show that the CH2 functional group has been decreased when comparing the non-irradiated/α-irradiated and α-irradiated/etched detectors, suggesting a degradation of the detectors due to alpha particle irradiation and also due to the different chemical etching treatments applied. The uncertainties have been determined and reported along with the results.