10 فروردین 1403
كوروش قيصري

کوروش قیصری

مرتبه علمی: دانشیار
نشانی: دانشکده علوم و فناوری نانو و زیستی - گروه فیزیک
تحصیلات: دکترای تخصصی / فیزیک هسته ای-راکتور
تلفن: 07731222242
دانشکده: دانشکده علوم و فناوری نانو و زیستی

مشخصات پژوهش

عنوان Assembly Neutron Moderation System for BNCT Based on a 252Cf Neutron Source
نوع پژوهش مقالات در نشریات
کلیدواژه‌ها
Epithermal neutron beam, Gamma ray contamination, MCNPX, BNCT, Neutron moderation system
مجله BMC Medical Physics
شناسه DOI 10.14316/pmp.2018.29.4.101
پژوهشگران کوروش قیصری (نفر اول) ، حبیب محمدی (نفر دوم)

چکیده

In this paper, a neutron moderation system for boron neutron capture therapy (BNCT) based on a 252Cf neutron source is proposed. Different materials have been studied in order to produce a high percentage of epithermal neutrons. A moderator with a construction mixture of AlF3 and Al, three reflectors of Al2O3, BeO, graphite, and seven filters (Bi, Cu, Fe, Pb, Ti, a two-layer filter of Ti+Bi, and a two-layer filter of Ti+Pb) is considered. The MCNPX simulation code has been used to calculate the neutron and gamma flux at the output window of the neutronic system. The results show that the epithermal neutron flux is relatively high for four filters: Ti+Pb, Ti+Bi, Bi, and Ti. However, a layer of Ti cannot reduce the contribution of g-rays at the output window. Although the neutron spectra filtered by the Ti+Bi and Ti+Pb overlap, a large fraction of neutrons (74.95%) has epithermal energy when the Ti+Pb is used as a filter. However, the percentages of the fast and thermal neutrons are 25% and 0.5%, respectively. The Bi layer provides a relatively low epithermal neutron flux. Moreover, an assembly configuration of 30% AlF3+70% Al moderator/Al2O3 reflector/a two-layer filter of Ti+Pb reduces the fast neutron flux at the output port much more than other assembly combinations. In comparison with a recent model suggested by Ghassoun et al., the proposed neutron moderation system provides a higher epithermal flux with a relatively low contamination of gamma rays.