The Impact of Laser on the Activation Energy and Sensitivity of CR-39 Detector

Abstract

The influence of laser radiation on bulk and etch rates, and as well detector sensitivity, before and after being irradiated with alpha particles at 5 MeV emitted from a 241Am source, are examined at different etching temperatures (65, 67, 69, 71, 73, 75, 77, 79 ,81, 83, and 85)C in this paper. A laser source with a wavelength of 480 nm and a pulse energy of 50 mJ/pulse at a repetition rate of 9 Hz was used to investigate the activation energy of a CR-39 polymer. The rates of bulk etch, Vb, and track etch, Vt, slightly increase with laser radiation. Whereas sensitivity decreases as temperature increases, besides, alpha-laser samples have quite better sensitivity than other samples. The activation energies of the bulk etch rates, Eb, are equivalent to 0.94 ± 0.07, 0.88 ± 0.05, and 0.95 ± 0.06 eV for laser-alpha, alpha-laser, and no laser samples, respectively. While, the activation energies associated with track etch rate, Et, for the CR-39 samples under study are 0.86 ± 0.04, 0.77 ± 0.03, and 0.76 ± 0.03 eV. The results manifest that laser exposure has a slight influence on activation energies of bulk etch rate within experimental uncertainties of the CR-39 samples. Additionally, the CR-39 set of laser-alpha samples reveals that Et is increased based on the cross-linking process. The increase in Et relates to hardening of the detector material, which has several uses, specifically in radiation detection.