سعیده خضری پور

Alpha particles emit electromagnetic radiation as they stop in the environment due to ionization and exciting atoms. The energy spectrum and intensity of radiation depends on the material and the percentage of elements in the target and its thickness. By placing layers of different metals and materials and changing their thickness in front of the entrance window of CsI (Tl) scintillator and interpreting the change in intensity in different detector channels, a suitable method for detecting alpha particles is introduced. In this research, the alpha particles of 241Am source with an energy of 5.48 MeV are irradiated into layers of aluminum, copper, iron, steel, paper, radiological films, lead and plastic with different thicknesses and was studied the count  variation of CsI (Tl) scintillation channels. By interpreting the results, was obtained the channels that show the maximum intensity of photons due alpha particles stopping in target. According to the observation of X-ray channels related to alpha particle stopping in target, a method for radon detection has also been introduced. In this method, hot spring water is poured into a plastic container with a thin layer of iron embedded at the end. First the background spectrum was measured. Then the water inside the container is stirred and the difference in spectrum is measured. The most suitable channel for measuring radon is channel 57. According to the obtained results, the relationship between radon concentration and counting rate in this channel has been extracted.