Monte Carlo study on effective source to surface distance for electron beams from a mobile dedicated IORT accelerator

2016 ◽  
Vol 16 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Mir Rashid Hosseini Aghdam ◽  
Hamid Reza Baghani ◽  
Seyed Rabi Mahdavi ◽  
Seyed Mahmoud Reza Aghamiri ◽  
Mohammad Esmail Akbari
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Beam Energy ◽  
Intraoperative Radiotherapy ◽  
Monte Carlo Study ◽  
Electron Beam Energy ◽  
Surface Distance ◽  
Mc Simulation ◽  
Mean Differences ◽  
Effective Source

AbstractPurposeThe effective source to surface distance (SSDeff) for different combinations of energy/applicator size of the electron beam produced by the light intraoperative accelerator, a mobile dedicated intraoperative radiotherapy accelerator, has been calculated in this study.MethodsBoth ionometric dosimetry and Monte Carlo (MC) simulation were followed to obtain the SSDeff for different combinations of electron energy/applicator size. Simulations were performed using Monte Carlo Nuclear Particles (MCNP) MC code. Measurements were performed by Advance Markus chamber and inside a polymethyl methacrylate slab phantom. Inverse square law method was employed to determine the SSDeff from acquired dosimetry data.ResultWith increasing the applicator diameter at a given energy, SSDeff is also increased. The same result is obtained with increasing the electron beam energy for a given applicator size. The results of MC-based SSDeff for 10 cm diameter reference applicator at different energies were in a good accordance with those obtained by ionometric dosimetry. The maximum and mean differences between the results were 1·1 and 0·6%, respectively.ConclusionsThe results of this study showed that SSDeff of intraoperative electron beam is highly dependent on the applicator size and is a mild function of electron beam energy. These facts are in accordance with those reported for conventional electron beam. The good agreement between the results of MC simulation and ionometric dosimetry confirms the application of MCNP code in modelling of intraoperative electron beam and obtaining the intended parameters.

Monte-Carlo Simulation of the Charge-Deposition Distribution for Electron-Beam Energy Determinations

2008 ◽  
Vol 53 (9(6)) ◽  
pp. 3754-3757 ◽  
Author(s):  
Youngmi Gil ◽  
Youngdo Oh ◽  
Sanghoon Kim ◽  
Sungik Moon ◽  
Moohyun Cho ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Beam ◽  
Beam Energy ◽  
Electron Beam Energy ◽  
Charge Deposition

Evaluating the radiation contamination dose around a high dose per pulse intraoperative radiotherapy accelerator: a Monte Carlo study

2020 ◽  
Vol 19 (3) ◽  
pp. 265-276
Author(s):  
Seyed Rashid Hosseini Aghdam ◽  
Zahra Siavashpour ◽  
Seyed Mahmoud Reza Aghamiri ◽  
Saied Rabie Mahdavi ◽  
Nahid Nafisi
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Intraoperative Radiotherapy ◽  
Monte Carlo Study ◽  
High Dose ◽  
Simulation Code ◽  
Energy Distance ◽  
Measurement Results ◽  
Radiation Contamination ◽  
Relative Differences

AbstractAim:In this study, the radiation contamination dose (RCD) for different combinations of electron energy/distance, applicator and radius around the light intraoperative accelerator (LIAC), a high dose per pulse dedicated intraoperative electron radiotherapy machine, has been estimated. Being aware about the amount of RCDs is highly recommended for linear medical electron accelerators.Methods and methods:Monte Carlo Nuclear Particles (MCNP) code was used to simulate the LIAC® head and calculate RCDs. Experimental RCDs measurements were also done by Advanced Markus chamber inside a MP3-XS water phantom. Relative differences of simulations and measurements were calculated.Result:RCD reduction by distance from the machine follows the inverse-square law, as expected. The RCD was decreased by increasing angle from applicator walls opposed to the electron beam direction. The maximum differences between the simulation and measurement results were lower than 3%.Conclusions:The RCD is strongly dependent on electron beam energy, applicator size and distance from the accelerator head. Agreement between the MCNP results and ionometric dosimetry confirms the applicability of this simulation code in modelling the intraoperative electron beam and obtaining the dosimetric parameters. The RCD is a parameter that would restrict working with LIAC in an unshielded operative room.

scholarly journals Determination of effective source to surface distance and cutout factor in small fields in electron beam radiotherapy: A comparison of different dosimeters

2020 ◽  
Vol 26 (4) ◽  
pp. 235-242
Author(s):  
Mohamad Reza Bayatiani ◽  
Fatemeh Fallahi ◽  
Akbar Aliasgharzadeh ◽  
Mahdi Ghorbani ◽  
Benyamin Khajetash ◽  
...  
Keyword(s):  
Electron Beam ◽  
Linear Accelerator ◽  
Beam Energy ◽  
Field Size ◽  
Surface Distance ◽  
Small Fields ◽  
Dosimetry System ◽  
Electron Beam Radiotherapy ◽  
Effective Source

AbstractObjective: The main purpose of this study is to calculate the effective source to surface distance (SSDeff) of small and large electron fields in 10, 15, and 18 MeV energies, and to investigate the effect of SSD on the cutout factor for electron beams a linear accelerator. The accuracy of different dosimeters is also evaluated.Materials and methods: In the current study, Elekta Precise linear accelerator was used in electron beam energies of 10, 15, and 18 MeV. The measurements were performed in a PTW water phantom (model MP3-M). A Semiflex and Advanced Markus ionization chambers and a Diode E detector were used for dosimetry. SSDeff in 100, 105, 110, 115, and 120 cm SSDs for 1.5 × 1.5 cm2 to 5 × 5 cm2 (small fields) and 6 × 6 cm2 to 20 × 20 cm2 (large fields) field sizes were obtained. The cutout factor was measured for the small fields.Results: SSDeff in small fields is highly dependent on energy and field size and increases with increasing electron beam energy and field size. For large electron fields, with some exceptions for the 20 × 20 cm2 field, this quantity also increases with energy. The SSDeff was increased with increasing beam energy and field size for all three detectors.Conclusion: The SSDeff varies significantly for different field sizes or cutouts. It is recommended that SSDeff be determined for each electron beam size or cutout. Selecting an appropriate dosimetry system can have an effect in determining cutout factor.

Analyzing Observed Composite Differences Across Groups

Methodology ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Holger Steinmetz
Keyword(s):  
Monte Carlo ◽  
Structural Equation Modeling ◽  
Measurement Invariance ◽  
Structural Equation ◽  
Monte Carlo Study ◽  
Equation Modeling ◽  
Factor Loadings ◽  
Latent Mean Differences ◽  
Partial Invariance ◽  
Mean Differences

Although the use of structural equation modeling has increased during the last decades, the typical procedure to investigate mean differences across groups is still to create an observed composite score from several indicators and to compare the composite’s mean across the groups. Whereas the structural equation modeling literature has emphasized that a comparison of latent means presupposes equal factor loadings and indicator intercepts for most of the indicators (i.e., partial invariance), it is still unknown if partial invariance is sufficient when relying on observed composites. This Monte-Carlo study investigated whether one or two unequal factor loadings and indicator intercepts in a composite can lead to wrong conclusions regarding latent mean differences. Results show that unequal indicator intercepts substantially affect the composite mean difference and the probability of a significant composite difference. In contrast, unequal factor loadings demonstrate only small effects. It is concluded that analyses of composite differences are only warranted in conditions of full measurement invariance, and the author recommends the analyses of latent mean differences with structural equation modeling instead.

ELECTRON BEAM ENERGY BRANCHING IN OXYGEN

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-777-C7-778
Author(s):  
G. Fournier ◽  
J. Bonnet ◽  
J. Bridet ◽  
J. Fort ◽  
D. Pigache
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Electron Beam Energy

scholarly journals Control of electron beam energy-spread by beam loading effects in a laser-plasma accelerator

2020 ◽  
Vol 62 (5) ◽  
pp. 055004 ◽  
Author(s):  
Guangyu Li ◽  
Quratul Ain ◽  
Song Li ◽  
Muhammad Saeed ◽  
Daniel Papp ◽  
...  
Keyword(s):  
Electron Beam ◽  
Laser Plasma ◽  
Beam Energy ◽  
Plasma Accelerator ◽  
Energy Spread ◽  
Electron Beam Energy ◽  
Beam Loading ◽  
Loading Effects ◽  
Laser Plasma Accelerator

Soft-X-ray spectra of highly charged Au ions in an electron-beam ion trap

2001 ◽  
Vol 79 (2-3) ◽  
pp. 153-162 ◽  
Author(s):  
E Träbert ◽  
P Beiersdorfer ◽  
K B Fournier ◽  
S B Utter ◽  
K L Wong
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Large Scale ◽  
Ion Trap ◽  
Electron Beam Energy ◽  
X Ray ◽  
Maximum Charge ◽  
Electron Beam Ion Trap ◽  
Atomic Structure Calculations ◽  
Structure Calculations

Systematic variation of the electron-beam energy in an electron-beam ion trap has been employed to produce soft-X-ray spectra (20 to 60 Å) of Au with well-defined maximum charge states ranging from Br- to Co-like ions. Guided by large-scale relativistic atomic structure calculations, the strongest Δn = 0 (n = 4 to n' = 4) transitions in Rb- to Cu-like ions (Au42+ – Au50+) have been identified. PACS Nos.: 32.30Rj, 39.30+w, 31.50+w, 32.20R

Electron-beam energy reconstruction for neutrino oscillation measurements

Nature ◽  
2021 ◽  
Vol 599 (7886) ◽  
pp. 565-570
Author(s):  
M. Khachatryan ◽  
A. Papadopoulou ◽  
A. Ashkenazi ◽  
F. Hauenstein ◽  
A. Nambrath ◽  
...  
Keyword(s):  
Electron Beam ◽  
Neutrino Oscillation ◽  
Beam Energy ◽  
Electron Beam Energy ◽  
Energy Reconstruction
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