الفهرس 
THEORETICAL ASPECTSOnly 14 pages are availabe for public view
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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.
We explained the relationship between the etching times and the track density for all energies when the fluence of alpha particles varies from the lowest fluency to the highest fluency. Which showed that at the highest fluence of alpha particles and increased etching time, the track density will increase and then gradually decrease as a result of the interference of the tracks with each other due to the increase in their size with each increase in the etching time.
the relationship between the energies of alpha and the track diameters from the lowest fluence of alpha particles to the highest fluence of alpha particles has been drawn, in each stage of the etching times starting from 2 h to 12 h. We find that the track diameter gradually increases in all energies.
The relationship between the etching times and the track diameters for all energies was drawn, we found that the track diameter increases gradually with an increase in the etching time.
Then the relationship between the etching time and the efficiency of alpha particles for all energies was clarified, found a varying difference in each of the available energies according to the difference in the fluency of the alpha particles from the lowest fluency to the highest fluency for each stage of the etching time.
We started by drawing the relationship between the etching time and all other parameters such as the bulk of each rate, which is one of the basic parameters in the emergence of tracks, including calculating the track etch rate along the trail. The ratio between the tracks each rate along the trail and the bulk of each rate, the etching efficiency, and the critical angle, as well as the calculation of the track length, the track depth.
After that, a comparison was made between the density of the path and its DROP and all other parameters that appeared after each chemical scraping process that was carried out on the surface of the detector for the energy of 3 MeV in the case of sodium hydroxide at a concentration of 6.25 N and when adding some other organic materials such as ethanol, methanol, benzene and acetone at a concentration of 1 molarity and 4 molarity. At a temperature of 70oC.