نتایج جستجو برای: mcnp 4c

تعداد نتایج: 4108  

Background: Obtaining high quality images in Single Photon Emission Tomography (SPECT) device  is the most important goal in nuclear medicine. Because if image quality is low, the possibility of making a mistake in diagnosing and treating the patient will rise. Studying effective factors in spatial resolution of imaging systems is thus deemed to be vital. One of the most important factors in S...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده علوم پایه 1390

در کارخانه تولید سوخت هسته ای علاوه بر وجود تشعشع و خطر پرتوگیری، خطر حالت بحرانی سیستم نیز وجود دارد. هنگامی که دقیقاً یک نوترون از هر شکافت برای شکافت بعدی تولید می شود سیستم را بحرانی می نامند. در فرآیند تولید پودر uo2(دی اکسید اورانیوم ) از (هگزا فلوراید اورانیوم) uf6 گازی با غنای 5 درصد احتمال رخداد حالت بحرانی زیاد است. در این تحقیق از کد mcnp 4c برای شبیه سازی تانک هیدرولیز در مرحله تبدیل...

Journal: :iranian journal of medical physics 0
zohreh dehghannia rostami graduated m.sc. student of nuclear physics, physics dept., kn toosi university of technology, tehran, iran. seyed farhad masoudi associate professor, physics dept., kn toosi university of technology, tehran. iran somayeh asadi graduated m.sc. student of nuclear physics, physics dept., kn toosi university of technology, tehran, iran.

introduction: in this paper, by complete definition of human eye containing the various parts and their materials, the difference between this model and a homogeneous water phantom are compared for two ophthalmic plaques using 125i and 103pd. material and methods: the simulation of the two phantoms were performed in the mcnp-4c code and by using the geometry of a three-dimensional eye, differen...

ژورنال: سنجش و ایمنی پرتو 2016

By use of silicon rubber as polymeric matrix and bismuth oxide as fillers, composite materials were fabricated up to 70 wt% and their gamma ray attenuation was studied. Due to the fair solubility of bismuth oxide particles in polymer matrix, the solution intercalation method is used for nanocomposite fabrication. The applied source for radiation attenuation test was 241Am with photon energies 5...

 ABSTRACTBackground: An electron beam generated X-ray spectrum consists of characteristic X-ray and continuous bermsstrahlung. The aim of this research is calculating and comparing X-ray spectra for different target filter of mammograms. Materials and Methods: Monte Carlo is a very powerful tool to simulate a series of different target-filter assembly in order to calculate the X-ray spectra. MC...

اطهری علاف, میترا, حسینی, سیدعلی,

  Given the role of Gas-Graphite reactors as the fourth generation reactors and their recently renewed importance, in 2002 the IAEA proposed a set of Benchmarking problems. In this work, we propose a model both efficient in time and resources and exact to simulate the HTR-10 reactor using MCNP-4C code. During the present work, all of the pressing factors in PBM reactor design such as the inter-...

Ghafourian, Haji-Shafeieha, Kakavand,

Background: Miniature neutron sources with high neutron flux have abundant applications in medicine, industry and researches. The most important general characteristic of miniature neutron sources is their diameter which is 3mm in average. In this research, we have surveyed and designed an Am-Be miniature neutron source fabrication. Materials and Methods: This investigation resulted in creation...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2006
Michael G Stabin Todd E Peterson George E Holburn Mary A Emmons

UNLABELLED The ability to estimate absorbed doses in experimental animals to which radiolabeled material has been administered may be important in explaining and controlling potential radiation toxicity observed during preclinical trials. Most previously reported models for establishing doses to small animals have been stylized and mathematically based. This study establishes dose factors for i...

Seyed Farhad Masoudi, Somayeh Asadi, Zohreh Dehghannia Rostami

Introduction: In this paper, by complete definition of human eye containing the various parts and their materials, the difference between this model and a homogeneous water phantom are compared for two ophthalmic plaques using 125I and 103Pd. Material and methods: The simulation of the two phantoms were performed in the MCNP-4C code and by using the geometry of a three-dimensional eye, differen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم پایه 1392

غده تیروئید می تواند دستخوش بیماری های متفاوتی شود که از جمله آنها پرکاری آن می باشد. یکی از روش های درمان پرکاری تیروئید استفاده از ید 131 می باشد. هدف اصلی در درمان با رادیوایزوتوپ ید ???، ایجاد بیشترین دوز جذبی در غده تیروئید و کمترین دوز ممکن در سایر اندام هاست؛ تا بیشترین اثر درمانی و کمترین عوارض جانبی ایجاد شود. برای سنجش توزیع دوز در بافت تیروئید معمولا توزیع یکنواخت ید در حجم تیروئید د...

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