نتایج جستجو برای: photon attenuation coefficient

تعداد نتایج: 284445  

Journal: :journal of biomedical physics and engineering 0
s. chatterjee indian institute of astrophysics, bangalore 560034, india a. vyas indian institute of astrophysics, bangalore 560034, india r. ravanfar haghighi medical physics unit, all india institute of medical sciences, ansari nagar, new delhi 110029 india p. kumar medical physics unit, all india institute of medical sciences, ansari nagar, new delhi 110029 india

introduction: the photoelectric attenuation coefficient of substances is known to depend upon the energy e of the photon and the effective atomic number of substances (zeff) as (zeff x /e y ).  no definitive values about these indices x, y are given in the literature. the index x is said to lie between, 3.0 and 4.0, while for ‘y’ different values have been assigned, between 3.0 and 4.0. methodo...

Journal: :iranian journal of radiation research 0
i. akkurt suleyman demirel university science faculty physics department, isparta, turkey h. canakci gaziantep university engineering faculty civil engine department, bol. gaziantep, turkey

background: radiation shielding properties is an important for a material wish can be used the photon attenuation coefficients of clay produced using different rate of boron have been measured for the purpose of radioactive waste disposal. materials and methods: the measurement has been performed using gamma spectrometer contains nai (tl) detector at the photon energies of 662, 1173 and 1332 ke...

Journal: :journal of biomedical physics and engineering 0
f seif arak university of medical sciences m j tahmasebi-birgani ahvaz jundishapur university of medical sciences m r bayatiani arak university of medical sciences

background: in this study, a method for linear attenuation coefficient calculation was introduced. methods: linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. the calculation was done for cerrobend as a common radiotherapy modifier and mercury. results: the valu...

Background: In this study, a method for linear attenuation coefficient calculation was introduced.Methods: Linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. The calculation was done for Cerrobend as a common radiotherapy modifier and Mercury.Results: The values...

2013
Sandeep Gupta Gurdeep Singh Sidhu

The variation in mass attenuation coefficient μ for total and partial photon interaction processes for three different oxide glasses (65CaO-35Al2O3(OG1) , 20Na2O-80SiO2(OG2), and 20Na2O-5Al2O3-75SiO2 (OG3)), in the incident energy range from 10 keV to 100 GeV has been studied using software package XCOM and the effect of chemical composition on the values of μ is also interpreted graphically. M...

2012
Folorunso O. Ogundare Samuel A. Ogundele Olumide O. Akerele Fatai A. Balogun

The ability of concrete to attenuate ionizing radiation intensity is assessed using its linear or mass attenuation coefficient. In this work, the broad-beam linear and mass attenuation coefficients of different types of soils and cements used for making concrete were measured at different photon energies (60-1333 keV), nearly spanning the diagnostic photon energy range, using a NaI detector. Th...

2015
Yuya Nakamura Seiji Tomiguchi Masayuki Tanaka

BACKGROUND Generally, attenuation correction is made by incorporating a linear attenuation coefficient, which is based on the attenuation coefficient map (mu-map) created from a computed tomography scan, into the ordered subsets-expectation maximization reconstruction method in non-uniform domains. A non-uniform Chang's attenuation correction method that uses the mu-map created from a computed ...

Introduction: Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.   Materials and Methods: In melting furnace, ...

Introduction: The present study aimed to evaluate the impact of PbO nano and micro-sized fillers on ordinary and heavy concretes for different photon energies. Material and Methods: The MCNPX Monte Carlo code (version 2.6.0) was used for all simulations in the present study. A model of narrow-beam geometry was validated and utilized to calcul...

A. Hamed, A.A. Beineen, A.E. El faki, J.A. Mars, K.E.M. Mohamadain, K.J. Cloete, M.D.M. Ali, M.E.M. Eisa,

Background: This study investigated the γ-rays shielding properties of some building materials in Sudan has been investigated. Materials and Methods: Photons attenuation coefficients and half value layer (HVL) were experimented using Cs-137 and Co-60 sources.  The measurements were performed to gauge the intensity of radiation when performed unshielded, the specific thickness of selected sample...

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