جستجوی مقالات مرتبط با کلیدواژه « Ionization radiation » در نشریات گروه « فیزیک »

The operation principle of calorimeters used for dosimetry of ionizing radiations is based on measuring the induced temperature difference in the adsorbent due to thermal energy deposition of the ionization radiation. In recent years, one of these methods has been the holographic optical calorimetry by laser beams. One of the problems that affect the response accuracy of the calorimeters is the heat transfer phenomenon in the adsorbent material. This phenomenon affects the measurement accuracy of the absorbed dose. In this work, using numerical coding in the FORTRAN environment, the dose profile change due to heat transfer effects in the PMMA tissue-equivalent material inside a holographic interferometry calorimeter has been investigated and the results have been compared with the finite element method results.

Rapid development in nuclear industry and medical applications involving radiation sources would increase the potential of exposure to the ionizing radiation. Due to the harmful effects of radiation exposure on the health of radiation workers, rapid dose estimation of the overexposed victims with high accuracy is quite important in taking appropriate medical treatment plan. Biological dosimetry based on micronucleous (MN) assay is a perfect technique with unique advantages for a fast triage in radiation accidents. To develop the dose response curve, blood samples of 16 healthy individuals in two groups of male and female and in two age ranges were collected and exposed to 0, 0.25, 0.5, 1, 2 and 4 Gy gamma rays, cultured, harvested, slides prepared and micronuclei in each dose scored. The results showed that the curve follow linear quadratic formula. In order to validate the performance of created dose response curve, two real accidental over-exposed workers and two unknown irradiated blood samples investigated by newly established curve and compared with results obtained by metaphase analysis (dicentric). The doses estimated by MN assay showed a very good conformity with those estimated by dicentric analysis, pointing out that the MN assay is a reliable, easier and valuable alternative method for biological dosimetry.