نتایج جستجو برای: scattered radiation

تعداد نتایج: 258284  

Dariush Sardari Mahdi Sadeghi, Niloofar Azadegan Seyed Pezhman Shirmardi,

Introduction: The proton beam produced in particle accelerators has an appropriate therapeutic potential. In this research, proton therapy of breast cancer is simulated using the MCNPX code in a MIRD phantom, also the contribution of scattered neutron dose during the proton therapy were calculated for the Heart, Lung and Liver.   Materials and Methods: For si...

Journal: :Journal of radiological protection : official journal of the Society for Radiological Protection 2008
J A Cole D J Platten

Currently in the UK, shielding calculations for computed tomography (CT) systems are based on the BIR-IPEM (British Institute of Radiology and Institute of Physics in Engineering in Medicine) working group publication from 2000. Concerns have been raised internationally regarding the accuracy of the dose plots on which this method depends and the effect that new scanner technologies may have. A...

Journal: :Journal of radiological protection : official journal of the Society for Radiological Protection 2012
D G Sutton C J Martin D Peet J R Williams

The specification of shielding for fluoroscopic facilities in the UK is based on the determination of scatter incident on a barrier using a simple formula linking kerma area product and scatter kerma. Over the last few years there has been a move to incorporate additional copper filtration in equipment used for high dose fluoroscopic and interventional examinations, and the existing formula doe...

Journal: :iranian journal of radiation research 0
m. hajizadeh saffar department of medical physics, mashhad university of medical sciences, mashhad, iran s. nekoee department of medical physics, mashhad university of medical sciences, mashhad, iran m.h. bahrayni-toosi department of medical physics, mashhad university of medical sciences, mashhad, iran a. sedghi department of medical physics, mashhad university of medical sciences, mashhad, iran

abstractbackground: as fluoroscopy or different angiographies are usually evaluated using tl dosimeter. thismethod is a time-consuming procedure therefore, radiologists are usually worried and unawareof their exact radiation dose received during each fluoroscopy or angiography. in this study, anew trend for quick estimation of effective dose based on measuring air-absorbed dose of thescattered ...

Journal: :Radiation protection dosimetry 2012
M Suric Mihic Z Vucic I Prlic I Lulic T Mestrovic

Security personnel who operate X-ray units for the control of hand luggage and personal items at airports are generally not under dosimetric surveillance. A significant increase in the number of inspected items per passenger, due to rigorous air traffic security measures, raises a question of extended exposure of these workers to scattered X-ray radiation. A new approach to investigating direct...

1999
KENNETH WOOD R. J. REYNOLDS

We present Monte Carlo simulations of the di†use Ha Galactic background. Our models comprise direct and multiply scattered Ha radiation from the kpc scale height warm ionized medium and midplane H II regions. The scattering is o† dust that is assumed to be well mixed with the gas, with an axisymmetric density distribution taken from the literature. The results of our simulations are all-sky Ha ...

2013
Bastian Bier Chris Schwemmer Andreas K. Maier Hannes G. Hofmann Yan Xia Joachim Hornegger Tobias Struffert

Patient dose reduction in C-arm computed tomography by volume-of-interest (VOI) imaging is becoming an interesting topic for many clinical applications. One limitation of VOI imaging that remains is the truncation artifact in the reconstructed 3-D volume. This artifact can either be a cupping effect towards the boundaries of the field-of-view (FOV) or an offset in the Hounsfield values of the r...

2003
J. P. Gastellu-Etchegorry V. Demarez V. Pinel F. Zagolski

T h e DART (discrete anisotropic radiative transfer) model simulates radiative transfer in heterogeneous 3-D scenes that may comprise different landscape features; i.e., leaves, grass, trunks, water, soil. The scene is divided into a rectangular cell matrix, i.e., building block for simulating larger scenes. Cells are parallelipipedic. Their optical properties are represented by individual scat...

Journal: :Applied optics 1969
J V Dave

Some results are presented to emphasize the need for using a fine increment while performing integrations over size distribution in computations of the characteristics of the radiation scattered by a unit volume of typical atmospheric aerosols.

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