نتایج جستجو برای: neutron flux

تعداد نتایج: 130682  

Asra Sadat Talebi Majid Jadidi Payman Hejazi Raheb Ghorbani

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

A new model is presented herein to calculate optimal value for ultra-cold neutron (UCN) production rate of a UCN source. The cold neutron (CN) converter is the main component of UCN source. In this paper, we study the UCN source which contains the D2O neutron moderator, the sD2 converter, 590 Mev proton beam, and the spallation target (a mixture of Pb, D2O and Zr). In order to determine the qua...

Asra Sadat Talebi Majid Jadidi Payman Hejazi Raheb Ghorbani

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

2011
R. B. M. Sogbadji B. J. B. Nyarko E. H. K. Akaho R. G. Abrefah

Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1 (GHARR-1) was measured after a beryllium reflector was added to its shim to compensate for excess reactivity loss. The thermal, epithermal and fast neutron fluxes were determined by the method of foil activation. The experimental sam...

Journal: :journal of biomedical physics and engineering 0
m t bahreyni toossi medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran b khajetash medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran m ghorbani medical physics department, faculty of medicine, mashhad university of medical sciences, mashhad, iran

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

ژورنال: سنجش و ایمنی پرتو 2014

In order to gain the neutron spectrum with proper components specification for BNCT, it is necessary to design a Beam Shape Assembling (BSA), including moderator, collimator, reflector, gamma filter and thermal neutrons filter, in front of the initial radiation beam from the source. According to the result of MCNP4Csimulation, the Northwest beam tube has the most optimized neutron flux between ...

ژورنال: سنجش و ایمنی پرتو 2020

The present study deals with a new method for measuring the power of a reactor. This method uses gamma and neutron radiation resulted from the entire reactor structure, without changing its structure (online). In terms of functionality, this method can measure the reactor power in real-time and report it instantly. In order to obtain the relationship between reactor power and gamma and neutron ...

2009
T. Sidery M. A. Alpar

We investigate dynamical coupling timescales of a neutron star’s superfluid core, taking into account the interactions of quantized neutron vortices with quantized flux lines of the proton superconductor in addition to the previously considered scattering of the charged components against the spontaneous magnetization of the neutron vortex line. We compare the cases where vortex motion is const...

Boron neutron capture therapy (BNCT) is an effective method for treatment of deep seated brain tumors. This method consists of two stages: injection of boron compound in the patient body, and then irradiation of the region tumors with the neutron beam. It allows for delivery of high linear energy transfer (LET) radiation (particles 4He and 7Li nuclei) to tumors at the cellular level whilst avoi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید