Results 201 to 210 of about 15,587 (228)
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Medical Physics, 2015
Purpose: Use of high density concrete for radiation shielding is increasing, trading cost for space savings associated with the reduced tenth value layer (TVL). Precise information on the attenuation properties of high-density concretes is not readily present in the literature.
S Tanny +4 more
exaly +2 more sources
Purpose: Use of high density concrete for radiation shielding is increasing, trading cost for space savings associated with the reduced tenth value layer (TVL). Precise information on the attenuation properties of high-density concretes is not readily present in the literature.
S Tanny +4 more
exaly +2 more sources
Medical Physics, 2009
Purpose:Several factors including radionuclide purity influence the photon energy spectra from sealed brachytherapy sources. The existence of impurities and trace elements in radioactive materials as well as the substrate and encapsulation may not only alter the spectrum at a given time but also cause change in the spectra as a function of time.
Ning J, Yue +4 more
openaire +2 more sources
Purpose:Several factors including radionuclide purity influence the photon energy spectra from sealed brachytherapy sources. The existence of impurities and trace elements in radioactive materials as well as the substrate and encapsulation may not only alter the spectrum at a given time but also cause change in the spectra as a function of time.
Ning J, Yue +4 more
openaire +2 more sources
TU‐EE‐A2‐04: Helical Tomotherapy Leakage Radiation Half and Tenth Value Layers in Concrete and Lead
Medical Physics, 2005Purpose: According to NCRP Report 51, if the leakage TVL is not measured, the primary radiation TVL should be used for the shielding design. Varian measured its own 90° leakage TVL in 1995. To determine which TVL value is most suitable for Hi‐Art II Tomotherapy, its leakage radiation half and tenth value layer in concrete and lead are measured. Methods
M Mirzasadeghi +6 more
openaire +1 more source
Medical Physics, 2009
Purpose: To investigate the impacts of spectral time dependence of brachytherapy source on shielding requirements and the Nth value layers NthVL). Method and Materials: The photon energy spectrum of brachytherapy sources is influenced by several factors including radionuclide purity.
N Yue +4 more
openaire +1 more source
Purpose: To investigate the impacts of spectral time dependence of brachytherapy source on shielding requirements and the Nth value layers NthVL). Method and Materials: The photon energy spectrum of brachytherapy sources is influenced by several factors including radionuclide purity.
N Yue +4 more
openaire +1 more source
Medical Physics, 2008
Purpose: The objectives of this study were to measure the leakage radiation levels surrounding the tomotherapy machine and to determine the tenth value layers (TVL) for concrete. Method and Materials: A custom designed shield was fabricated with Cerrobend to shield a 1000cc spherical ionization‐chamber used in these measurements.
S Goddu +7 more
openaire +1 more source
Purpose: The objectives of this study were to measure the leakage radiation levels surrounding the tomotherapy machine and to determine the tenth value layers (TVL) for concrete. Method and Materials: A custom designed shield was fabricated with Cerrobend to shield a 1000cc spherical ionization‐chamber used in these measurements.
S Goddu +7 more
openaire +1 more source
Health Physics, 2007
The calculation of shielding barrier thicknesses for radiation therapy facilities according to the NCRP formalism is based on the use of broad beams (that is, the maximum possible field sizes). However, in practice, treatment fields used in radiation therapy are, on average, less than half the maximum size.
Adnan K, Jaradat, Peter J, Biggs
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The calculation of shielding barrier thicknesses for radiation therapy facilities according to the NCRP formalism is based on the use of broad beams (that is, the maximum possible field sizes). However, in practice, treatment fields used in radiation therapy are, on average, less than half the maximum size.
Adnan K, Jaradat, Peter J, Biggs
openaire +2 more sources
Health Physics, 2007
Tenth-value-layers (TVLs) for a 6 MV stereotactic radiosurgery (SRS) x-ray beam have been computed using Monte Carlo methods for radiation transport simulation. The first and equilibrium TVLs were determined in the three most common building materials used in radiation therapy vault construction: ordinary concrete, lead, and steel (iron).
openaire +2 more sources
Tenth-value-layers (TVLs) for a 6 MV stereotactic radiosurgery (SRS) x-ray beam have been computed using Monte Carlo methods for radiation transport simulation. The first and equilibrium TVLs were determined in the three most common building materials used in radiation therapy vault construction: ordinary concrete, lead, and steel (iron).
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Medical Physics, 2008
As different types of radionuclides (e.g., source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL).
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As different types of radionuclides (e.g., source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL).
openaire +2 more sources
Medical physics – the current status, problems, the way of development. Innovation technologies
Introduction. The article addresses the significant differences observed in the tenth-value layers (TVL) of leakage radiation attenuation in concrete for medical linear accelerators (linacs) between internationally recognized methodologies of the National Council on Radiation Protection and Measurements (NCRP) and the International Atomic Energy Agency
Dmytro BIELYKH +3 more
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Introduction. The article addresses the significant differences observed in the tenth-value layers (TVL) of leakage radiation attenuation in concrete for medical linear accelerators (linacs) between internationally recognized methodologies of the National Council on Radiation Protection and Measurements (NCRP) and the International Atomic Energy Agency
Dmytro BIELYKH +3 more
openaire +1 more source
Medical Physics, 2006
Treatment room shielding design depends on barrier attenuation data. It is common practice to use tenth‐value‐layers (TVLs) or related quantities measured for a given beam quality and shielding material. This investigation has applied Monte Carlo simulation to accurately determine the first, second and third TVLs for the three most common building ...
openaire +1 more source
Treatment room shielding design depends on barrier attenuation data. It is common practice to use tenth‐value‐layers (TVLs) or related quantities measured for a given beam quality and shielding material. This investigation has applied Monte Carlo simulation to accurately determine the first, second and third TVLs for the three most common building ...
openaire +1 more source