نتایج جستجو برای: photon radial distribution

تعداد نتایج: 727027  

Journal: :journal of medical signals and sensors 0
hamid-reza sadoughi shahrokh nasseri mahdi momennezhad hamid-reza sadeghi mohammad hossein bahreyni

radiotherapy dose calculations can be evaluated by monte carlo (mc) simulations with acceptable accuracy for dose prediction in complicated treatment plans. in this work, standard, livermore and penelope electromagnetic (em) physics packages of geant4 application for tomographic emission (gate) 6.1 were compared versus monte carlo n-particle extended (mcnpx) 2.6 in simulation of 6 mv photon lin...

ژورنال: سنجش و ایمنی پرتو 2020

Radiotherapy using linear accelerators is known as an effective modality for cancer treatment. The photons energy of treatment beams significantly affect the dose distribution. Therefore, it is important to accurately evaluate the photon energy spectra. In this study, MCNPX Monte Carlo code (version 2.6.0) was used to simulate an 18 MV photon beam of a Varian 2100C/D linear accelerator. By matc...

Journal: :iranian journal of medical physics 0
hashem rafii-tabar computational physical sciences research laboratory, school of nano science, institute for research in fundamental sciences (ipm), tehran, iran neda rafieiolhosseini department of medical physics and biomedical engineering, school of medicine, shahid beheshti university of medical sciences, tehran, iran

all biological samples emit ultra-low intensity light without any external stimulation. recently, scientific communities have paid particular attention to this phenomenon, known as ultra-weak photon emission (upe). upe has been introduced in the literature as an alternative for biophoton, low-level chemiluminescence and ultra-weak bioluminescence, while it differs from ordinary bioluminescence,...

Journal: :iranian journal of radiation research 0
m. zehtabian radiation research center and radiation medicine department, school of engineering, shiraz university, shiraz, iran r. faghihi radiation research center and radiation medicine department, school of engineering, shiraz university, shiraz, iran s. sina radiation research center and radiation medicine department, school of engineering, shiraz university, shiraz, iran

background: iodine brachytherapy sources with low photon energies have been widely used in treating cancerous tumors. dosimetric parameters of brachytherapy sources should be determined according to aapm tg-43u1 recommendations before clinical use. monte carlo codes are reliable tools in calculation of these parameters for brachytherapy sources. materials and methods: dosimetric parameters (dos...

M. Zehtabian, R. Faghihi, S. Sina,

Background: Iodine brachytherapy sources with low photon energies have been widely used in treating cancerous tumors. Dosimetric parameters of brachytherapy sources should be determined according to AAPM TG-43U1 recommendations before clinical use. Monte Carlo codes are reliable tools in calculation of these parameters for brachytherapy sources. Materials and Methods: Dosimetric param...

Journal: :Medical physics 2005
Michael K Fix Paul J Keall Jeffrey V Siebers

One limitation to the widespread implementation of Monte Carlo (MC) patient dose-calculation algorithms for radiotherapy is the lack of a general and accurate source model of the accelerator radiation source. Our aim in this work is to investigate the sensitivity of the photon-beam subsource distributions in a MC source model (with target, primary collimator, and flattening filter photon subsou...

Journal: :پژوهش فیزیک ایران 0
احمد شیرانی m. h. alamatsaz محمد حسن علامت ساز a. shirani

monte carlo simulation is widely used in calculations involing transport of photons through different materials of different shapes. the method consists of randomly generating a finite set of photon histories over which the quantities of interest are averaged. in photon transport calculations, sampling the photon scattering angle from the klein-nishina probability distribution is of special imp...

Journal: :مهندسی قدرت ایران 0
a parizad iran university of science and technology, iran a.h akhazali iran university of science and technology (iust), iran mohsen kalantar iran university of science and technology (iust)

due to the increasing interest on renewable sources in recent years, the studies on integration of distributed generation to the power grid have rapidly increased. in order to minimize line losses of power systems, it is crucially important to define the size and location of local generation to be placed. minimizing the losses in the system would bring two types of saving, in real life, one is ...

In the present study, temporal behavior of entanglement between photonic binomial distributions and a two-level atom in a leaky cavity, in equilibrium with the environment at a temperature T, is studied. In this regard, the master equation is solved in the secular approximation for the density matrix, when the initial photonic distribution is binomial, while the atomic states obey the Boltzmann...

احمد شیرانی, , محمد حسن علامت ساز, ,

  Monte Carlo simulation is widely used in calculations involing transport of photons through different materials of different shapes. The method consists of randomly generating a finite set of photon histories over which the quantities of interest are averaged. In photon transport calculations, sampling the photon scattering angle from the Klein-Nishina probability distribution is of special i...

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