نتایج جستجو برای: neutron effect
تعداد نتایج: 1684090 فیلتر نتایج به سال:
Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...
Upon increasing needs and vast application of neutron detectors, especially in nuclear reactors and growing number of linear accelerators, design and manufacturing of neutron detectors is a serious demand. The aim of this project is building neutron detectors capable of compensating gamma and temperature response in a radiation media. A special thermocouple coated with Boron carbide at the junc...
Neutron sources employed in different applications in both medicine and industry. Due to the harmful effects of neutron particles on living organisms, radiation shields have played a vital role in radiation protection against neutrons. In recent decade, numerous investigations conducted on the design and fabrication of nanocomposites as more efficient shielding materials against fast and therma...
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...
In this work, a neutron irradiating system containing six Am/Be neutron sources in a graphite moderator, which produces a relatively high and uniform thermal neutron flux in an irradiating cavity at the center of the system , has been simulated .The thermal neutron flux in the center of the system has then been calculated and compared with experimental results measured in a cavity a...
Four matrix-phase crystallographic directions of IN718 are investigated by in-situ tensile tests using neutron diffraction. The elastic diffraction constants for all directions measured are compared to theoretical values calculated by the Kröner model. The differences between the microscopic and the macroscopic material response are given. The accumulation of microstrains in the different cryst...
beryllium chemical combination has a considerable effect on the design and fabrication of the241am9be neutron source. in this investigation the beryllium combinations were studied as a generator ofneutrons with various mass percentage, and the neutron yields were also calculated using the results of thealice and srim codes calculations per unit incident charge. the neutron yields of beryllium ...
Employing High-energy photons in medical linear accelerators can lead to neutron contamination. The relative biological effect of neutrons is 20 times higher than photons. Consequently, its damage to the biological tissue is much higher and unobtrusive. In this study, we calculated neutron equivalent dose in a medical linear accelerator by the FLUKA Monte Carlo code system. The results show tha...
background: in neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials. objective: the purpose of this study is to evaluate dose distribution in the presence of 10 b , 157 gd and 33 s ne...
objective: using megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. the crucial problem for using photon beams >8mv is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. the contaminated neutrons produced in different components of the accelerator head and rely on many param...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید