scholarly journals A Monte Carlo study of high-energy photon transport in matter: application for multiple scattering investigation in Compton spectroscopy

2016 ◽  
Vol 23 (1) ◽  
pp. 244-252 ◽  
Author(s):  
Marek Brancewicz ◽  
Masayoshi Itou ◽  
Yoshiharu Sakurai
Keyword(s):  
Monte Carlo ◽  
Multiple Scattering ◽  
Monte Carlo Study ◽  
High Energy ◽  
X Rays ◽  
Simulation Algorithm ◽  
Energy Photon ◽  
Restricted Geometry ◽  
First Results ◽  
Photon Splitting

The first results of multiple scattering simulations of polarized high-energy X-rays for Compton experiments using a new Monte Carlo program,MUSCAT, are presented. The program is developed to follow the restrictions of real experimental geometries. The new simulation algorithm uses not only well known photon splitting and interaction forcing methods but it is also upgraded with the new propagation separation method and highly vectorized. In this paper, a detailed description of the new simulation algorithm is given. The code is verified by comparison with the previous experimental and simulation results by the ESRF group and new restricted geometry experiments carried out at SPring-8.

Advanced kernel methods vs. Monte Carlo-based dose calculation for high energy photon beams

2009 ◽  
Vol 93 (3) ◽  
pp. 645-653 ◽  
Author(s):  
Irina Fotina ◽  
Peter Winkler ◽  
Thomas Künzler ◽  
Jochen Reiterer ◽  
Isabell Simmat ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Kernel Methods ◽  
Dose Calculation ◽  
High Energy ◽  
High Energy Photon ◽  
Photon Beams ◽  
Energy Photon

ON THE RELATION BETWEEN THE WIDTH OF CHARGE BALANCE FUNCTION AND HADRONIZATION TIME IN RELATIVISTIC HEAVY ION COLLISION

2007 ◽  
Vol 16 (10) ◽  
pp. 3355-3362
Author(s):  
DU JIAXIN ◽  
LI NA ◽  
LIU LIANSHOU
Keyword(s):  
Monte Carlo ◽  
Strong Dependence ◽  
Monte Carlo Study ◽  
Heavy Ion ◽  
High Energy ◽  
Relativistic Heavy Ion Collisions ◽  
Heavy Ion Collision ◽  
Balance Function ◽  
Charge Balance ◽  
Ion Collision

A Monte Carlo study on the charge balance function in high energy hadron-hadron and relativistic heavy ion collisions are carried out using the Monte Carlo generators PYTHIA and AMPT, respectively. A strong dependence of the width of balance function on multiplicity is found in both cases. Using the mean parton-freeze-out time of a heavy-ion-collision event as the characteristic hadronization time for the event, it is found that for a fixed multiplicity interval the width of balance function is consistent with being independent of hadronization time.

scholarly journals The Influence of Brass Compensator Thickness and Field Size on Neutron Contamination Spectrum in 18MV Elekta SL 75/25 Medical Linear Accelerator with and without Flattening Filter: A Monte Carlo Study

2018 ◽  
Vol 8 (3Sep) ◽  
Author(s):  
A S Talebi ◽  
M Maleki ◽  
P Hejazi ◽  
M Jadidi ◽  
R Ghorbani
Keyword(s):  
Monte Carlo ◽  
Linear Accelerator ◽  
Monte Carlo Study ◽  
High Energy ◽  
Nonparametric Tests ◽  
Primary Electron ◽  
Field Size ◽  
Dose Ratio ◽  
Medical Linear Accelerator ◽  
Flattening Filter

BackgroundOne of the most significant Intensity Modulated Radiation Therapy treatment benefits is a high target to normal tissue dose ratio. To improve this advantage, an additional accessory such as a compensator is used to delivering doses. Compensator-based IMRT treatment is usually operated with an energy higher than 10 MV. Photoneutrons, which have high linear energy transfer and radiobiological effectiveness, are produced by colliding high-energy photon beams with linear accelerator structures, then they deliver the unwanted doses to patients and staff. Therefore, the neutron energy spectra should be determined in order to calculate and reduce the photoneutron risk.Objective: We have conducted a comprehensive and precise study on the influence of brass compensator thickness and field size on neutron contamination spectrum in an Elekta SL 75/25 medical linear accelerator with and without the flattening filter by Monte Carlo method.Materials and Methods: MCNPX MC Code version 2.6.0 was utilized to simulate the detailed geometry of Elekta SL 75/25 head components based on Linac’s manual. This code includes an important feature to simulate the photo-neutron interactions. Photoneutrons spectrum was calculated after the Linac output benchmarking based on tuning the primary electron beam.Results and Conclusion: Based on the Friedman and Wilcoxon nonparametric tests results (P<0.05), photoneutron fluence directly depends on the field size and compensator thickness. Moreover, the unflattened beam provides lower photoneutron fluence than the flattened beam. Photoneutrons fluence is not negligible in compensator-based IMRT treatment. However, in order to optimize treatment plans, this additional and unwanted dose must be accounted for patients.

scholarly journals A Monte Carlo Study on Dose Enhancement in the Presence of Nanoparticles by Photon Source: A Comparison between Various Concentration and Material of Nanoparticles

2021 ◽  
Author(s):  
Arezoo Kazemzadeh ◽  
Habiballah Moradi
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Study ◽  
High Energy ◽  
Energy Sources ◽  
Photon Beams ◽  
Treatment Efficiency ◽  
Dose Enhancement ◽  
Gold Silver ◽  
Photon Source ◽  
Energetic Photon

Purpose: Recently, the application of high atomic number nanoparticles is suggested in the field of radiotherapy to improve physical dose enhancement and hence treatment efficiency. Several factors such as concentration and material of nanoparticles and energy of beam define the amount of dose enhancement in the target in the presence of nanoparticles. Materials and Methods: In this approach, a spherical cell was simulated through the Geant4 Monte Carlo toolkit which contained a nucleus and nanoparticles distributed through the cell. To investigate the effect of the concentration of nanoparticles on the deposited dose, it ranged from 3 mg/g to 30 mg/g for different materials like gold, silver, gadolinium, and platinum. Also, various mono-energetic photon beams included low and high energy sources were applied. Results: The results proved that as the concentration increased, the Dose Enhancement Factor (DEF) enlarged. Overall, almost for all energy and material that were used in this study, the maximum of DEF values occurred in the concentration of 30 mg/g. Moreover, lower energy sources presented higher DEF compared to other sources. The results indicated that the highest amount of DEF transpired for 35 keV photon beams equal to 14.67. Also, the K-edge energy of each material affects DEF values. Conclusion: To obtain a better outcome in the use of nanoparticles in combination with radiotherapy, a higher concentration of nanoparticles and low-energy photons should be considered to optimize the DEF and thus the treatment ratio.

A micro-focusing and high-flux-throughput beamline design using a bending magnet for microscopic XAFS at the High Energy Photon Source

2019 ◽  
Vol 26 (5) ◽  
pp. 1835-1842
Author(s):  
Kun Tang ◽  
Lei Zheng ◽  
Yi Dong Zhao ◽  
Shu Hu Liu ◽  
Chen Yan Ma ◽  
...  
Keyword(s):  
Optical Design ◽  
High Energy ◽  
X Rays ◽  
High Energy Photon ◽  
Virtual Source ◽  
Energy Photon ◽  
Synchrotron Source ◽  
Full Field ◽  
Mirror Pair ◽  
Photon Source

An optical design study of a bending-magnet beamline, based on multi-bend achromat storage ring lattices, at the High Energy Photon Source, to be built in Beijing, China, is described. The main purpose of the beamline design is to produce a micro-scale beam from a bending-magnet source with little flux loss through apertures. To maximize the flux of the focal spot, the synchrotron source will be 1:1 imaged to a virtual source by a toroidal mirror; a mirror pair will be used to collimate the virtual source into quasi-parallel light which will be refocused by a Kirkpatrick–Baez mirror pair. In the case presented here, a beamline for tender X-rays ranging from 2.1 keV to 7.8 keV, with a spot size of approximately 7 µm (H) × 6 µm (V) and flux up to 2 × 1012 photons s−1, can be achieved for the purpose of X-ray absorption fine-structure (XAFS)-related experiments, such as scanning micro-XAFS and full-field nano-XAFS.

218. Jarvik2000 and radiotherapy. Irradiation with high-energy photon beams and first results

2018 ◽  
Vol 56 ◽  
pp. 194-195
Author(s):  
R. Giménez De Lorenzo ◽  
R. Navarra ◽  
D. Marinelli ◽  
N. Adorante ◽  
S. Giancaterino ◽  
...  
Keyword(s):  
High Energy ◽  
High Energy Photon ◽  
Photon Beams ◽  
Energy Photon ◽  
First Results
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