Investigation of Some Factors Affecting the Efficiency of Solid State Nuclear Track Detectors for Alpha-Particles

Abstract

This study aims to investigate some of the factors that affect the efficiency of SSNTD solid nuclear trace detectors by using one of the most widely used types of detectors, CR-39. Initially, alpha particles are dropped from one of the used radioactive sources, americium 241 with an energy of 5.49 MeV. Then several different energies were extracted from this source, through the relationship between the energy of alpha and the range of alpha in the air. From the range of alpha particles that we have, the distance between the source and the detector will be calculated for each energy we want to extract, by using the inverse square law which is related to the intensity of radiation and the distance of the source. Then we draw the relationship between the energies of alpha particles and the distance, the relationship between them has been an inverse relationship. Hence, the relationship between the alpha energies and the range of alpha was drawn, and the relationship between them was direct, that is means when increases the alpha energy the range of alpha particles was increases with it. After the irradiation process, we begin to determine the shape of the track of the alpha particles formed on the surface of the detector. Through some qualitative and quantitative analyzes of CR-39 that were recorded on the surface of the detector after the fall of the alpha particles. that is through the process of chemical etching using a chemical solution such as sodium hydroxide solution at 6.25 N at a temperature of 70 oC and with different etching times starting from 2 h to 12 h. We drew the relationship between the fluency of alpha particles and the track density when the temperature is fixed for 2 h for all the extracted energies which begin with the energy of 1 MeV to 5 MeV. We drew a relation between the fluency of alpha particles and the track density with the gradual increase in temperature and fix it in each stage until we reach 12 hours of chemical etching for all energies. After the etching time started to increase from 9 to 12 h, we noted that the track density was decreased, as a result of, the overlap of the tracks.