Monte Carlo estimation of photoneutrons contamination from high-energy X-ray medical accelerators in treatment room and maze: a simplified model

2009 ◽  
Vol 135 (1) ◽  
pp. 21-32 ◽  
Author(s):  
M. Zabihzadeh ◽  
M. R. Ay ◽  
M. Allahverdi ◽  
A. Mesbahi ◽  
S. R. Mahdavi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Simplified Model ◽  
X Ray ◽  
Treatment Room ◽  
Monte Carlo Estimation

scholarly journals Monte Carlo Modeling and Design of Photon Energy Attenuation Layers for >10× Quantum Yield Enhancement in Si-Based Hard X-ray Detectors

Instruments ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Eldred Lee ◽  
Kaitlin M. Anagnost ◽  
Zhehui Wang ◽  
Michael R. James ◽  
Eric R. Fossum ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Quantum Yield ◽  
Photon Energy ◽  
High Efficiency ◽  
High Energy ◽  
Yield Enhancement ◽  
X Ray ◽  
Simulation Results ◽  
Conversion Efficiencies

High-energy (>20 keV) X-ray photon detection at high quantum yield, high spatial resolution, and short response time has long been an important area of study in physics. Scintillation is a prevalent method but limited in various ways. Directly detecting high-energy X-ray photons has been a challenge to this day, mainly due to low photon-to-photoelectron conversion efficiencies. Commercially available state-of-the-art Si direct detection products such as the Si charge-coupled device (CCD) are inefficient for >10 keV photons. Here, we present Monte Carlo simulation results and analyses to introduce a highly effective yet simple high-energy X-ray detection concept with significantly enhanced photon-to-electron conversion efficiencies composed of two layers: a top high-Z photon energy attenuation layer (PAL) and a bottom Si detector. We use the principle of photon energy down conversion, where high-energy X-ray photon energies are attenuated down to ≤10 keV via inelastic scattering suitable for efficient photoelectric absorption by Si. Our Monte Carlo simulation results demonstrate that a 10–30× increase in quantum yield can be achieved using PbTe PAL on Si, potentially advancing high-resolution, high-efficiency X-ray detection using PAL-enhanced Si CMOS image sensors.

High energy electron and X-ray scattering from atoms using Monte Carlo methods

1996 ◽  
Vol 388 ◽  
pp. 7-17 ◽  
Author(s):  
S.A. Alexander ◽  
R.L. Coldwell ◽  
Ruth E. Hoffmeyer ◽  
Ajit J. Thakkar
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Methods ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Towards mapping turbulence in the intra-cluster medium

2019 ◽  
Vol 629 ◽  
pp. A143 ◽  
Author(s):  
Nicolas Clerc ◽  
Edoardo Cucchetti ◽  
Etienne Pointecouteau ◽  
Philippe Peille
Keyword(s):  
Monte Carlo ◽  
Structure Function ◽  
Velocity Structure ◽  
High Energy ◽  
Sample Variance ◽  
Physical Parameters ◽  
Sample Mean ◽  
X Ray ◽  
Spatially Resolved ◽  
Mean And Variance

Context. X-ray observations of galaxy clusters provide insights into the nature of gaseous turbulent motions, their physical scales, and the fundamental processes to which they are related. Spatially-resolved, high-resolution spectral measurements of X-ray emission lines provide diagnostics on the nature of turbulent motions in emitting atmospheres. Since they are acting on scales comparable to the size of the objects, the uncertainty on these physical parameters is limited by the number of observational measurements, through sample variance. Aims. We propose a different and complementary approach to repeating numerical simulations for the computation of sample variance (i.e. Monte-Carlo sampling) by introducing new analytical developments for lines diagnosis. Methods. We considered the model of a “turbulent gas cloud”, consisting in isotropic and uniform turbulence described by a universal Kolmogorov power-spectrum with random amplitudes and phases in an optically thin medium. Following a simple prescription for the four-term correlation of Fourier coefficients, we derived generic expressions for the sample mean and variance of line centroid shift, line broadening, and projected velocity structure function. We performed a numerical validation based on Monte-Carlo simulations for two popular models of gas emissivity based on the β-model. Results. Generic expressions for the sample variance of line centroid shifts and broadening in arbitrary apertures are derived and match the simulations within their range of applicability. Generic expressions for the mean and variance of the structure function are provided and verified against simulations. An application to the Athena/X-IFU (Advanced Telescope for High-ENergy Astrophysics/X-ray Integral Field Unit) and XRISM/Resolve (X-ray Imaging and Spectroscopy Mission) instruments forecasts the potential of sensitive, spatially-resolved spectroscopy to probe the inertial range of turbulent velocity cascades in a Coma-like galaxy cluster. Conclusions. The formulas provided are of generic relevance and can be implemented in forecasts for upcoming or current X-ray instrumentation and observing programmes.

3-D Structure of Nanosized Catalysts by High-Energy X-ray Diffraction and Reverse Monte Carlo Simulations:  Study of Ru

2007 ◽  
Vol 111 (49) ◽  
pp. 18214-18219 ◽  
Author(s):  
N. Bedford ◽  
C. Dablemont ◽  
G. Viau ◽  
P. Chupas ◽  
V. Petkov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
High Energy ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanosized Catalysts

MONTE CARLO ESTIMATION OF RADIATION DOSES IN RED BONE MARROW AND BREAST IN COMMON PEDIATRIC X-RAY EXAMINATIONS

2008 ◽  
Vol 95 (3) ◽  
pp. 331-336 ◽  
Author(s):  
George I. Gialousis ◽  
Emmanuel N. Yakoumakis ◽  
Anastasios I. Dimitriadis ◽  
Zografia K. Papouli ◽  
Nikolaos E. Yakoumakis ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Monte Carlo ◽  
Radiation Doses ◽  
Red Bone Marrow ◽  
X Ray ◽  
Monte Carlo Estimation

scholarly journals The structure of molten CuCl: Reverse Monte Carlo modeling with high-energy X-ray diffraction data and molecular dynamics of a polarizable ion model

2016 ◽  
Vol 145 (9) ◽  
pp. 094503 ◽  
Author(s):  
Olga Alcaraz ◽  
Joaquim Trullàs ◽  
Shuta Tahara ◽  
Yukinobu Kawakita ◽  
Shin’ichi Takeda
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Diffraction Data ◽  
High Energy ◽  
Reverse Monte Carlo ◽  
X Ray Diffraction ◽  
Monte Carlo Modeling ◽  
X Ray

Monte Carlo studies on dose conversion factors from graphite to water for high energy X-ray beams

2020 ◽  
Vol 171 ◽  
pp. 108760 ◽  
Author(s):  
Y.H. Kim ◽  
C.Y. Yi ◽  
I.J. Kim ◽  
B.C. Kim ◽  
J.H. Kim ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Energy ◽  
Conversion Factors ◽  
X Ray ◽  
Monte Carlo Studies
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