Alpha spectrometry study on LR 115 and Makrofol through measurements of track diameter

Measurements of alpha track etch-pit diameters (from a ²⁴¹Am source) are reported for CR-39, LR 115 and Makrofol detectors. The first detector was used to calibrate the source, whereas the possibility of alpha spectroscopy was investigated in the others. A ²²⁶Ra source was also used for CR-39 to detect a higher energy (≈6.96 MeV). The data found for CR-39 are in agreement with previous results. LR 115 and Makrofol presented the characteristic Bragg peak, which indicates that these detectors can be used as alpha spectrometers. Finally, within the applied etching conditions, it was possible to observe energy detection windows for LR 115 and Makrofol. For the etching conditions employed in this work, maximum energy thresholds were found to be approximately 4.5 MeV and 3.7 MeV, for LR 115 and Makrofol, respectively. Therefore, our results indicate alpha particle tracks from plated-out radon progeny would be naturally excluded if these detectors were used to monitor environmental radon and its progeny, confirming previous results performed with different experimental conditions. - Highlights: ► Alpha spectrometry through track diameter was investigated in plastic detectors. ► CR-39 was used to calibrate the ²⁴¹Am source. ► Makrofol and LR-115 presented energy detection window, avoiding the plate-out effect. ► Spectrometry in Makrofol was achieved with ordinary chemical etching