نتایج جستجو برای: neutron shield
تعداد نتایج: 53966 فیلتر نتایج به سال:
background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...
Background: Prompt gamma neutron activation analysis (PGNAA) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. Also it is a valuable diagnostic tool for total body elemental measurements. 252Cf and 241Am-Be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...
background: monte carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the mcnb4b monte carlo code. the simulations were carried out for the three common neutron sources, namely the 252cf, the 241am/be and the dd neutron generator w...
Background and Aim: One of the best radiotherapy methods that have been suggested for the treatment of cancers such as brain, head and neck, skin, and recently liver is boron neutron capture therapy. Therefore, neutron shielding in the treatment room is important because the absorption of neutrons in the shield may lead to the production of gamma rays, which can have destructive effects. While ...
In this study, a mixture of waste lead mine Nakhlak and cement with different percentages of boric acid are used to construct a proper shield for gamma and neutron radiations emitted from the Am-Be source. Neutron dose rate reduction by the prepared samples was investigated by thermal neutron irradiation system of Isfahan University, TLD 600 and TLD 700. Neutron dose rate changes, compressive...
Background: Monte Carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. Advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the MCNB4B Monte Carlo code. The simulations were carried out for the three common neutron sources, namely the 252Cf, the 241Am/Be and the DD neutron generator w...
Background: Polyethylene composites including boron can be used as an effective neutron shield. Our investigation focuses on manufacturing borated polyethylene nano-composite. The purpose of this study is to design a radiation shield for use in both neutron and gamma fields. Materials and Methods: Borated polyethylene shields containing 2%, and 5% weight percentage of Boron nano-particles w...
background: polyethylene composites including boron can be used as an effective neutron shield. our investigation focuses on manufacturing borated polyethylene nano-composite. the purpose of this study is to design a radiation shield for use in both neutron and gamma fields. materials and methods: borated polyethylene shields containing 2%, and 5% weight percentage of boron nano-particles were ...
Introduction: One of the concerns about using of high energy photons in radiotherapy is neutron contamination production. The threshold energy of photoneutron production in most materials with high atomic number is about 7MeV. Therefore, it seems to be logical that the main components with high atomic number elements used in the LINAC head have a large contribution to the neutr...
background: several landmine detection methods, based on nuclear techniques, have been suggested during the recent years. neutron energy moderation, neutron-induced gamma emission, neutron and gamma attenuation, and fast neutron backscattering are nuclear-based methods used for landmine detection. the aim of this study is to use backscattered neutron for landmine detection. materials and method...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید