Results 81 to 90 of about 493,079 (334)

Lower Bound on the Cosmic TeV Gamma-ray Background Radiation [PDF]

, 2015
The Fermi gamma-ray space telescope has revolutionized our understanding of the cosmic gamma-ray background radiation in the GeV band. However, investigation on the cosmic TeV gamma-ray background radiation still remains sparse. Here, we report the lower bound on the cosmic TeV gamma-ray background spectrum placed by the cumulative flux of individual ...
arxiv   +1 more source

Multi‐institutional study on image quality for a novel CBCT solution on O‐ring linac

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Introduction This work presents a multi‐institutional study on image quality provided by a novel cone beam computed tomography (CBCT). The main goal is to investigate the consistency of imaging performance across multiple institutions.
Luis Agulles‐Pedrós, R. Lee MacDonald, Amanda Jean Cherpak, Nayha Dixit, Lei Dong, Tianyu Zhao, Kundan Thind, Anthony Doemer, Boon‐Keng Teo, Shiqin Su, Alexander Moncion, James L. Robar   +11 more
wiley   +1 more source

Quantum limitations of distant radiating objects detection

Физика волновых процессов и радиотехнические системы, 2014
Weak electromagnetic signals from sufficiently distant sources reveal quantum properties. The latter ones result that detection of the sources becomes probabilistic.
A.L. Kurakin
doaj  

Evaluation of the dose reduction effect of crystalline lens exposure in cone‐beam computed tomography with bismuth eye shield for image‐guided radiation therapy: An anthropomorphic phantom study

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract This study aimed to evaluate the dose‐exposure reduction effect of a crystalline lens with a bismuth eye shield using cone‐beam computed tomography (CBCT) for head image‐guided radiation therapy. The ocular surface dose of the head phantom (THRA‐1) is defined as a crystalline lens exposure dose and is measured using a radiophotoluminescence ...
Tatsuya Yoshida, Koji Sasaki, Yoshiyuki Kawasaki, Tomoki Hayakawa, Toshiyuki Kawadai, Takako Shibasaki   +5 more
wiley   +1 more source

The anisotropy properties of a background radiation in the fractal cosmological model [PDF]

arXiv, 2012
We consider the anisotropy properties of a background radiation in the fractal cosmological model. The space of this model includes self-similar domains. The metric tensors of any two domains are connected by the discrete scaling transformation. Photons of the background radiation cross the domain and their energy change.
arxiv  

From 2D to 3D gamma passing rate tolerance and action limits for patient‐specific quality assurance in volumetric‐modulated arc therapy

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Background Volumetric modulated arc therapy (VMAT) requires an accurate patient‐specific quality assurance (PSQA) program. In clinical practice, this is usually performed using the γ‐index and the two‐dimensional gamma passing rate (2D %GP). A three‐dimensional (3D) index incorporating the patient anatomy could be more useful for the 3D dose ...
Christos Zarros, George Patatoukas, Nikos Kollaros, Marina Chalkia, Andromachi Kougioumtzopoulou, Vasilios Kouloulias, Kalliopi Platoni   +6 more
wiley   +1 more source

Analysis of cosmic microwave background radiation in the presence of Lorentz violation [PDF]

arXiv, 2007
We examine the effects Lorentz violation on observations of cosmic microwave background radiation. In particular, we focus on changes in polarization caused by vacuum birefringence. We place stringent constraints on previously untested violations.
arxiv  

Does dose calculation algorithm affect the dosimetric accuracy of synthetic CT for MR‐only radiotherapy planning in brain tumors?

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose This study compares the dosimetric accuracy of deep‐learning‐based MR synthetic CT (sCT) in brain radiotherapy between the Analytical Anisotropic Algorithm (AAA) and AcurosXB (AXB). Additionally, it proposes a novel metric to predict the dosimetric accuracy of sCT for individual post‐surgical brain cases.
Jeffrey C. F. Lui, Francis K. H. Lee, C. C. Law, James C. H. Chow   +3 more
wiley   +1 more source

THE COSMIC MICROWAVE BACKGROUND RADIATION* [PDF]

Annals of the New York Academy of Sciences, 1981
Because angular anisotropies and spectral distortions of the cosmic microwave background radiation are judged to be inevitable at some level, in a realistic cosmological model, the evidence for spectral distortions and its theoretical implications are described.
openaire   +2 more sources

Modelling of a double‐scattering proton therapy nozzle using the FLUKA Monte Carlo code and analysis of linear energy transfer in patients treated for prostate cancer

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Background The dose‐averaged linear energy transfer (LETD) in proton therapy (PT) has in pre‐clinical studies been linked to the relative biological effectiveness (RBE) of protons. Until recently, the most common PT delivery method in prostate cancer has been double‐scattered PT, with LETD only available through dedicated Monte Carlo (MC ...
Rasmus Klitgaard, Lars Fredrik Fjæra, Camilla Hanquist Stokkevåg, Perry Johnson, Mark Artz, Nancy Price Mendenhall, Curtis Bryant, Ludvig Paul Muren   +7 more
wiley   +1 more source