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21 results on '"Jeremy M. C. Brown"'

1. Report on G4-Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group

Author

Dosatsu Sakata, David Bolst, D. H. Wright, Mihaly Novak, A. Perales, Edward Simpson, Christian Fedon, F. Romano, Paolo Dondero, Luciano Pandola, Ioanna Kyriakou, Bruce A. Faddegon, Toshiyuki Toshito, M. A. Cortés-Giraldo, Dmitri Konstantinov, Marie-Claude Bordage, Anatoly B. Rosenfeld, Luis Sarmiento, Yann Perrot, Pedro Arce, Giacomo Cuttone, Vladimir Ivanchenko, Carlo Mancini-Terracciano, Chihiro Omachi, J. M. Quesada, Sebastien Incerti, Dean L Cutajar, M. Maire, Ioannis Sechopoulos, José Ramos-Méndez, P. Cirrone, A. Le, Jeremy M. C. Brown, Susanna Guatelli, A. Mantero, G. Latyshev, Andrea Dotti, Giada Petringa, Laurent Desorgher, Takashi Sasaki, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), and Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

Subjects
Monte Carlo method, Geant4, medical physics, CROSS-SECTIONS, 030218 nuclear medicine & medical imaging, DOSE POINT KERNELS, 0302 clinical medicine, MEV ELECTRONS, benchmarking, Monte Carlo, [PHYS]Physics [physics], PROTON-THERAPY, Large Hadron Collider, medical applications, Medical simulation, Physics, STOPPING-LENGTH TARGETS, Observable, General Medicine, Benchmarking, 3. Good health, Women's cancers Radboud Institute for Health Sciences [Radboudumc 17], Other Physical Sciences, Nuclear Medicine & Medical Imaging, 030220 oncology & carcinogenesis, MULTIPLE-SCATTERING, MONTE-CARLO-SIMULATION, Monte Carlo simulations, radiotherapy, hadrotherapy, Monte Carlo Method, medicine.medical_specialty, Oncology and Carcinogenesis, Biomedical Engineering, Article, 03 medical and health sciences, Regression testing, medicine, Web application, Medical physics, Computer Simulation, BACKSCATTERING COEFFICIENT, Radiometry, radiotherapy, business.industry, THICK TARGETS, hadrotherapy, Reference data, NEUTRON YIELDS, business
Abstract

Background: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. Aims: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. Materials and Methods: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. Results: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. Discussion: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. Conclusion: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application. Ministerio de Economía y Competitividad FPA2016-77689-C2-1-R National Institutes of Health U24CA215123 France-Greece PICS 8235 European Space Agency 4000126645/19/NL/BW Australian Research Council ARC DP170100967, DP170102423 Susan G Komen Foundation for the Cure IIR13262248

Published
2021
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2. An electromagnetic physics constructor for low energy polarised X-/gamma ray transport in Geant4

Author

Jeremy M. C. Brown and Matthew Richard Dimmock

Subjects
Physics, Nuclear and High Energy Physics, X-ray astronomy, Gamma-ray astronomy, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Compton scattering, Polarimetry, Gamma ray, FOS: Physical sciences, Geant4, Computational Physics (physics.comp-ph), Synchrotron, Synchrotron radiation facility, Computational physics, law.invention, Beamline, law, Polarized gamma ray, Physics - Computational Physics, Instrumentation
Abstract

The production, application, and/or measurement of polarised X-/gamma rays are key to the fields of synchrotron science and X-/gamma-ray astronomy. The design, development and optimisation of experimental equipment utilised in these fields typically relies on the use of Monte Carlo radiation transport modelling toolkits such as Geant4. In this work the Geant4 "G4LowEPPhysics" electromagnetic physics constructor has been reconfigured to offer a "best set" of electromagnetic physics models for studies exploring the transport of low energy polarised X-/gamma rays. An overview of the physics models implemented in "G4LowEPPhysics", and it's experimental validation against Compton X-ray polarimetry measurements of the BL38B1 beamline at the SPring-8 synchrotron (Sayo, Japan) is reported. "G4LowEPPhysics" is shown to be able to reproduce the experimental results obtained at the BL38B1 beamline (SPring-8) to within a level of accuracy on the same order as Geant4's X-/gamma ray interaction cross-sectional data uncertainty (approximately $\pm$ 5 \%)., Comment: Geant4, Polarized gamma ray, Compton scattering, X-ray astronomy, Gamma-ray astronomy, Synchrotron radiation facility

Published
2021

3. Evaluation of early radiation DNA damage in a fractal cell nucleus model using Geant4-DNA

Author

Shogo Okada, Dousatsu Sakata, K. Murakami, David Sarramia, Vladimir Ivanchenko, Mario A. Bernal, Ivan Petrović, Sebastien Incerti, Ioanna Kyriakou, Marie-Claude Bordage, Wook Geun Shin, Sylvain Meylan, H.N. Tran, Dimitris Emfietzoglou, David Bolst, Takashi Sasaki, Giovanni Santin, Carmen Villagrasa, Vincent Breton, Nicolas Tang, Oleg Belov, Susanna Guatelli, Petteri Nieminen, Nathanael Lampe, Aleksandra Ristić-Fira, Jeremy M. C. Brown, Ziad Francis, M. Karamitros, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches en Cancérologie de Toulouse (CRCT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de dosimétrie des rayonnements ionisants (IRSN/PSE-SANTE/SDOS/LDRI), Service de dosimétrie (IRSN/PSE-SANTE/SDOS), and Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

Subjects
Radiobiology, Time Factors, DNA damage, Monte Carlo method, Biophysics, General Physics and Astronomy, Radiation, Models, Biological, 030218 nuclear medicine & medical imaging, Ionizing radiation, 03 medical and health sciences, 0302 clinical medicine, medicine, Animals, Radiology, Nuclear Medicine and imaging, DNA Breaks, Double-Stranded, DNA Breaks, Single-Stranded, Monte Carlo simulation, Physics, Cell Nucleus, [PHYS]Physics [physics], Geant4-DNA, business.industry, General Medicine, Chromatin, medicine.anatomical_structure, Fractals, 030220 oncology & carcinogenesis, Radiation protection, business, Nucleus, Monte Carlo Method, DNA Damage
Abstract

The advancement of multidisciplinary research fields dealing with ionising radiation induced biological damage – radiobiology, radiation physics, radiation protection and, in particular, medical physics – requires a clear mechanistic understanding of how cellular damage is induced by ionising radiation. Monte Carlo (MC)simulations provide a promising approach for the mechanistic simulation of radiation transport and radiation chemistry, towards the in silico simulation of early biological damage. We have recently developed a fully integrated MC simulation that calculates early single strand breaks (SSBs)and double strand breaks (DSBs)in a fractal chromatin based human cell nucleus model. The results of this simulation are almost equivalent to past MC simulations when considering direct/indirect strand break fraction, DSB yields and fragment distribution. The simulation results agree with experimental data on DSB yields within 13.6% on average and fragment distributions agree within an average of 34.8%. © 2019 Associazione Italiana di Fisica Medica

Published
2019
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4. Muon event localisation with AI

Author

J. Heredge, J.W. Archer, C. Webster, S. Krishnan, Susanna Guatelli, Alan R. Duffy, Federico Scutti, and Jeremy M. C. Brown

Subjects
Physics, Nuclear and High Energy Physics, Light intensity, Silicon photomultiplier, Muon, Physics::Instrumentation and Detectors, Design of experiments, Detector, Photodetector, Scintillator, Instrumentation, Algorithm, Event (particle physics)
Abstract

Low-cost muon detectors utilising cheap plastic scintillators and a limited number of individual silicon photomultipliers (SiPMs) offer a compelling approach to cheap experimental designs, provided the event localisation of a traversing particle can be accurately determined. In this theoretical work, we use Geant4 to simulate a diverse range of detector configurations, shapes and SiPM photosensors, predicting the light intensity received at a given SiPM. Testing a range of methods to localise muon events we determine that machine learning techniques outperform analytic models, and of these, a simple gradient boosted framework is the most reliably accurate localisation technique for our simulated scintillators. We find that a simple square scintillator outperforms other geometries and that AI performs, when applied to this shape, with a linear relationship between the positional accuracy of the event recovery and the average distance between photosensors around the detector perimeter.

Published
2021
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5. Simulation of Auger electron emission from nanometer-size gold targets using the Geant4 Monte Carlo simulation toolkit

Author

B. Suerfu, A. Mantero, Mario A. Bernal, Jeremy M. C. Brown, V. Ivantchenko, Ziad Francis, Sebastien Incerti, H.N. Tran, M. Karamitros, and J. Xu

Subjects
Physics, Nuclear and High Energy Physics, Auger electron spectroscopy, Photon, Auger effect, Proton, Physics::Medical Physics, Monte Carlo method, Spectral line, 030218 nuclear medicine & medical imaging, Computational physics, Auger, 03 medical and health sciences, symbols.namesake, 0302 clinical medicine, 030220 oncology & carcinogenesis, symbols, Nanomedicine, Atomic physics, Instrumentation
Abstract

A revised atomic deexcitation framework for the Geant4 general purpose Monte Carlo toolkit capable of simulating full Auger deexcitation cascades was implemented in June 2015 release (version 10.2 Beta). An overview of this refined framework and testing of its capabilities is presented for the irradiation of gold nanoparticles (NP) with keV photon and MeV proton beams. The resultant energy spectra of secondary particles created within and that escape the NP are analyzed and discussed. It is anticipated that this new functionality will improve and increase the use of Geant4 in the medical physics, radiobiology, nanomedicine research and other low energy physics fields.

Published
2016
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6. Progress of Geant4 electromagnetic physics developments and applications

Author

Mihaly Novak, Samer Bakr, A. S. Howard, Ioanna Kyriakou, D. Bernard, Helmut Burkhardt, Farah Hariri, Marilena Bandieramonte, Soon Yung Jun, I. Semeniouk, Sebastien Incerti, Sabine Elles, Vladimir Grichine, D Sawkey, Jeremy M. C. Brown, Vladimir Ivanchenko, M. Maire, L. Urbán, O Kadri, Marie-Claude Bordage, Susanna Guatelli, Paolo Dondero, A. Mantero, Alexander Bagulya, Anton V. Sokolov, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches en Cancérologie de Toulouse (CRCT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Geant4 Collaboration, and Laboratoire d'Annecy de Physique des Particules (LAPP)

Subjects
Physics, Free electron model, Large Hadron Collider, [PHYS.PHYS]Physics [physics]/Physics [physics], 010308 nuclear & particles physics, Scattering, QC1-999, Bremsstrahlung, Electron, Photoelectric effect, 01 natural sciences, 030218 nuclear medicine & medical imaging, Computing and Computers, Nuclear physics, 03 medical and health sciences, 0302 clinical medicine, Positron, 0103 physical sciences, Nuclear Physics - Experiment, Electron scattering
Abstract

International audience; We report on developments of the Geant4 electromagnetic physics sub-libraries of Geant4 release 10.4 and beyond. Modifications are introduced to the models of photoelectric effect, bremsstrahlung, gamma conversion, single and multiple scattering. The theory-based Goudsmit-Saunderson model of electron/positron multiple scattering has been recently reviewed and a new improved version, providing the most accurate results for scattering of electrons and positrons, was made available. The updated interfaces, models and configurations have already been integrated into LHC applications and may be useful for any type of simulations

Published
2018
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7. Statistical Image Reconstruction for High-Throughput Thermal Neutron Computed Tomography

Author

Daniele Pelliccia, Jeremy M. C. Brown, and Ulf Garbe

Subjects
Physics, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, business.industry, Neutron imaging, Neutron tomography, FOS: Physical sciences, 02 engineering and technology, Filter (signal processing), Iterative reconstruction, Instrumentation and Detectors (physics.ins-det), 021001 nanoscience & nanotechnology, Neutron temperature, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Neutron, Computer vision, Tomography, Artificial intelligence, 0210 nano-technology, business, Instrumentation, Throughput (business)
Abstract

Neutron Computed Tomography (CT) is an increasingly utilised non-destructive analysis tool in material science, palaeontology, and cultural heritage. With the development of new neutron imaging facilities (such as DINGO, ANSTO, Australia) new opportunities arise to maximise their performance through the implementation of statistically driven image reconstruction methods which have yet to see wide scale application in neutron transmission tomography. This work outlines the implementation of a convex algorithm statistical image reconstruction framework applicable to the geometry of most neutron tomography instruments with the aim of obtaining similar imaging quality to conventional ramp filtered back-projection via the inverse Radon transform, but using a lower number of measured projections to increase object throughput. Through comparison of the output of these two frameworks using a tomographic scan of a known 3 material cylindrical phantom obtain with the DINGO neutron radiography instrument (ANSTO, Australia), this work illustrates the advantages of statistical image reconstruction techniques over conventional filter back-projection. It was found that the statistical image reconstruction framework was capable of obtaining image estimates of similar quality with respect to filtered back-projection using only 12.5% the number of projections, potentially increasing object throughput at neutron imaging facilities such as DINGO eight-fold.

Published
2018

8. Mechanistic DNA damage simulations in Geant4-DNA part 1: A parameter study in a simplified geometry

Author

Vincent Breton, M. Karamitros, David Sarramia, Jeremy M. C. Brown, Dousatsu Sakata, Ioanna Kyriakou, Nathanael Lampe, Sebastien Incerti, Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont ( LPC ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Centre d'Etudes Nucléaires de Bordeaux Gradignan ( CENBG ), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
Models, Molecular, Work (thermodynamics), DNA damage, Monte Carlo method, Biophysics, General Physics and Astronomy, Electrons, Geometry, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Low energy, Radiology, Nuclear Medicine and imaging, Physics, [PHYS]Physics [physics], [ PHYS ] Physics [physics], DNA, General Medicine, Highly sensitive, chemistry, 030220 oncology & carcinogenesis, Yield (chemistry), Nucleic Acid Conformation, Monte Carlo Method, DNA Damage, Single strand
Abstract

International audience; Mechanistic modelling of DNA damage in Monte Carlo simulations is highly sensitive to the parameters that define DNA damage. In this work, we use a simple testing geometry to investigate how different choices of physics models and damage model parameters can change the estimation of DNA damage in a mechanistic DNA damage simulation built in Geant4-DNA. The choice of physics model can lead to variations by up to a factor of two in the yield of physically induced strand breaks, and the parameters that determine scavenging, and physical and chemical single strand break induction can have even larger consequences. Using low energy electrons as primary particles, a variety of parameters are tested in this geometry in order to arrive at a parameter set consistent with past simulation studies. We find that the modelling of scavenging can play an important role in determining results, and speculate that high-scavenging regimes, where only chemical radicals within 1 nm of DNA are simulated, could provide a good means of testing mechanistic DNA simulations

Published
2018
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9. Recent progress of GEANT4 electromagnetic physics for LHC and other applications

Author

M. Karamitros, Alexander Bagulya, Vladimir Ivanchenko, Mauro Tacconi, Mihaly Novak, M. Maire, Jeremy M. C. Brown, Helmut Burkhardt, Luciano Pandola, L. Urbán, Pier-Giorgio Rancoita, Susanna Guatelli, D Sawkey, K Mashtakov, Sebastien Incerti, Vladimir Grichine, O Kadri, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), and Laboratoire d'Annecy de Physique des Particules (LAPP)

Subjects
History, High energy, 01 natural sciences, Electromagnetic radiation, Education, Set (abstract data type), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], [INFO]Computer Science [cs], Aerospace engineering, 010302 applied physics, Physics, energy: high, Large Hadron Collider, 010308 nuclear & particles physics, business.industry, Scattering, multiple scattering, Computer Science Applications, Computing and Computers, Automatic Keywords, CERN LHC Coll, electromagnetic, GEANT, interface, User interface, business, Particle Physics - Experiment
Abstract

International audience; We report on the recent progress within the Geant4 electromagnetic physics subpackages. Several new interfaces and models recently introduced are already used in LHC applications and may be useful for any type of simulation. Significant developments were carried out to improve the user interface, develop models of single and multiple scattering, and validate high energy models. Part of these developments are included in the Geant4 10.2 release and the full set are available in the new version 10.3 of December, 2016.

Published
2017
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10. A low energy bound atomic electron Compton scattering model for Geant4

Author

David M. Paganin, John E. Gillam, Jeremy M. C. Brown, and Matthew Richard Dimmock

Subjects
Elastic scattering, Physics, Nuclear and High Energy Physics, Photon, Scattering, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Compton scattering, Electron, Inelastic scattering, Two-body problem, Computational physics, Atomic physics, Instrumentation
Abstract

A two-body fully relativistic three-dimensional scattering framework has been utilised to develop an alternative Compton scattering computational model to those adapted from Ribberfors’ work for Monte Carlo modelling of Compton scattering. Using a theoretical foundation that ensures the conservation of energy and momentum in the relativistic impulse approximation, this new model, the Monash University Compton scattering model, develops energy and directional algorithms for both the scattered photon and ejected Compton electron from first principles. The Monash University Compton scattering model was developed to address the limitation of the Compton electron directionality algorithms of other computational models adapted from Ribberfors’ work. Here the development of the Monash University Compton scattering model, including its implementation in a Geant4 low energy electromagnetic physics class, G4LowEPComptonModel, is outlined. Assessment of the performance of G4LowEPComptonModel was undertaken in two steps: (1) comparison with respect to the two standard Compton scattering classes of Geant4 version 9.5, G4LivermoreComptonModel and G4PenelopeComptonModel, and (2) experimental comparison with respect to Compton electron kinetic energy spectra obtained from the Compton scattering of 662 keV photons off the K-shell of gold. Both studies illustrate that the Monash University Compton scattering model, and in turn G4LowEPComptonModel, is a viable replacement for the majority of computational models that have been adapted from Ribberfors’ work. It was also shown that the Monash University Compton scattering model is able to reproduce the Compton scattering triply differential cross-section Compton electron kinetic energy spectra of 662 keV photons K-shell scattering off of gold to within experimental uncertainty.

Published
2014
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11. Laplacian Erosion: An Image Deblurring Technique for Multi-Plane Gamma-Cameras

Author

Matthew Richard Dimmock, John E. Gillam, David M. Paganin, and Jeremy M. C. Brown

Subjects
Physics, Nuclear and High Energy Physics, Deblurring, Planar Imaging, Image quality, business.industry, Monte Carlo method, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Imaging phantom, Optics, Nuclear Energy and Engineering, Computer Science::Computer Vision and Pattern Recognition, Electrical and Electronic Engineering, business, Laplace operator, Image restoration
Abstract

Laplacian Erosion, an image deblurring technique for multi-plane Gamma-cameras, has been developed and tested for planar imaging using a GEANT4 Monte Carlo model of the Pixelated Emission Detector for RadioisOtopes (PEDRO) as a test platform. A contrast and Derenzo-like phantom composed of 125I were both employed to investigate the dependence of detection plane and pinhole geometry on the performance of Laplacian Erosion. Three different pinhole geometries were tested. It was found that, for the test system, the performance of Laplacian Erosion was inversely proportional to the detection plane offset, and directly proportional to the pinhole diameter. All tested pinhole geometries saw a reduction in the level of image blurring associated with the pinhole geometry. However, the reduction in image blurring came at the cost of signal to noise ratio in the image. The application of Laplacian Erosion was shown to reduce the level of image blurring associated with pinhole geometry and improve recovered image quality in multi-plane Gamma-cameras for the targeted radiotracer 125I.

Published
2013
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12. Simulating the Impact of the Natural Radiation Background on Bacterial Systems: Implications for Very Low Radiation Biological Experiments

Author

Hervé Seznec, Vincent Breton, Pierre Marin, Lydia Maigne, Jeremy M. C. Brown, Sebastien Incerti, David Sarramia, Nathanael Lampe, David Biron, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), School of Mathematics and Physics [Belfast], Queen's University [Belfast] (QUB), Interface Physique et Chimie pour le Vivant (IPCV), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Mutation rate, Radiobiology, lcsh:Medicine, 030218 nuclear medicine & medical imaging, Ionizing radiation, 0302 clinical medicine, Radiation, Ionizing, Radiative transfer, Relative biological effectiveness, Background Radiation, lcsh:Science, [PHYS]Physics [physics], Physics, Likelihood Functions, Muons, Multidisciplinary, Radiation, Simulation and Modeling, Physical Sciences, Elementary Particles, Research Article, Electrons, Research and Analysis Methods, [SDV.MP.PRO]Life Sciences [q-bio]/Microbiology and Parasitology/Protistology, Microbiology, 03 medical and health sciences, Escherichia coli, Genetics, Point Mutation, Computer Simulation, Particle Physics, Nuclear Physics, Nucleons, Evolutionary Biology, Bacterial Evolution, business.industry, lcsh:R, Biology and Life Sciences, Dose-Response Relationship, Radiation, Bacteriology, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Organismal Evolution, Computational physics, 030104 developmental biology, 13. Climate action, Mutation, Ionizing Radiation, Microbial Evolution, Particle, lcsh:Q, Dose rate, Nuclear medicine, business
Abstract

International audience; At very low radiation dose rates, the effects of energy depositions in cells by ionizing radiation is best understood stochastically, as ionizing particles deposit energy along tracks separated by distances often much larger than the size of cells. We present a thorough analysis of the stochastic impact of the natural radiative background on cells, focusing our attention on E. coli grown as part of a long term evolution experiment in both underground and surface laboratories. The chance per day that a particle track interacts with a cell in the surface laboratory was found to be 6 × 10−5 day−1, 100 times less than the expected daily mutation rate for E. coli under our experimental conditions. In order for the chance cells are hit to approach the mutation rate, a gamma background dose rate of 20 μGy hr−1 is predicted to be required.

Published
2016
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13. Recent developments in Geant4

Author

Vladimir Grichine, Sebastien Incerti, G.O. Depaola, A. Galoyan, Andrea Dotti, Maria A.M. Reis, T. Yamashita, Enrico Bagli, Davide Mancusi, Ziad Francis, Helmut Burkhardt, J. I. Shin, Pekka Kaitaniemi, K. Amako, Tatsumi Koi, M. Raine, Pedro Arce, Ivan Petrović, John Allison, Nicolas A. Karakatsanis, D. Sawkey, Alexey Bogdanov, Victor Daniel Elvira, Giovanni Santin, X. Dong, Douglas Wright, M.H. Kelsey, S. Y. Jun, Maria Grazia Pia, K. Murakami, P. Gumplinger, S. B. Lee, Makoto Asai, J Perl, Jerome Verbeke, V. V. Uzhinsky, S. Hwang, J. M. Quesada, D. Brandt, Vladimir Ivanchenko, L. Garnier, Giorgio Ivan Russo, A. Mantero, Alexander Bagulya, Francesco Longo, B. Morgan, G. Barrand, Susanna Guatelli, T. Nikitina, Igor Strakovsky, H.N. Tran, Francesco Romano, B. R. Beck, Sw. Banerjee, D. Cano-Ott, M. Gayer, F.W. Jones, Ph Canal, Luciano Pandola, Paul Gueye, Toshiyuki Toshito, M. A. Cortés-Giraldo, Kyung-Suk Cho, Tsukasa Aso, A. Ristic Fira, Alexander Howard, G. Cosmo, Gunter Folger, John Apostolakis, Hisaya Kurashige, Giacomo Cuttone, Ivana Hřivnáčová, B. Tome, E. Mendoza, Stephane Chauvie, M. Karamitrosi, A. Taborda, Gene Cooperman, Satoshi Tanaka, H. Wenzel, B. Wendt, K. Genser, Takashi Sasaki, D. H. Wright, Pete Truscott, L. Urbán, Alberto Ribon, M. Verderi, P. Paprocki, M. Maire, A. Ivanchenko, Akinori Kimura, W. Pokorski, H. Yoshida, Jeremy M. C. Brown, A. Lechner, G.A.P. Cirrone, J. Yarba, Laurent Desorgher, Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire d'Orsay (IPNO), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Service des Réacteurs et de Mathématiques Appliquées (SERMA), Département de Modélisation des Systèmes et Structures (DM2S), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Service d’Études des Réacteurs et de Mathématiques Appliquées (SERMA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Allison, J., Amako, K., Apostolakis, J., Arce, P., Asai, M., Aso, T., Bagli, E., Bagulya, A., Banerjee, S., Barrand, G., Beck, B. R., Bogdanov, A. G., Brandt, D., Brown, J. M. C., Burkhardt, H., Canal, Ph., Cano-Ott, D., Chauvie, S., Cho, K., Cirrone, G. A. P., Cooperman, G., Cortés-Giraldo, M. A., Cosmo, G., Cuttone, G., Depaola, G., Desorgher, L., Dong, X., Dotti, A., Elvira, V. D., Folger, G., Francis, Z., Galoyan, A., Garnier, L., Gayer, M., Genser, K. L., Grichine, V. M., Guatelli, S., Guãye, P., Gumplinger, P., Howard, A. S., Hřivnã¡čovã¡, I., Hwang, S., Incerti, S., Ivanchenko, A., Ivanchenko, V. N., Jones, F. W., Jun, S. Y., Kaitaniemi, P., Karakatsanis, N., Karamitrosi, M., Kelsey, M., Kimura, A., Koi, T., Kurashige, H., Lechner, A., Lee, S. B., Longo, F., Maire, M., Mancusi, D., Mantero, A., Mendoza, E., Morgan, B., Murakami, K., Nikitina, T., Pandola, L., Paprocki, P., Perl, J., Petrović, I., Pia, M. G., Pokorski, W., Quesada, J. M., Raine, M., Reis, M. A., Ribon, A., Ristić Fira, A., Romano, F., Russo, G., Santin, G., Sasaki, T., Sawkey, D., Shin, J. I., Strakovsky, I. I., Taborda, A., Tanaka, S., Tomã©, B., Toshito, T., Tran, H. N., Truscott, P. R., Urban, L., Uzhinsky, V., Verbeke, J. M., Verderi, M., Wendt, B. L., Wenzel, H., Wright, D. H., Wright, D. M., Yamashita, T., Yarba, J., and Yoshida, H.

Subjects
MONTE-CARLO DOSIMETRY, LIQUID WATER, Nuclear and High Energy Physics, Exploit, PAIR PRODUCTION, MODELS, Nuclear physics, ENERGY ELECTROMAGNETIC, HEAVY-ION COLLISIONS, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, QA76, 030218 nuclear medicine & medical imaging, High energy physic, 03 medical and health sciences, 0302 clinical medicine, Software, HADRON-NUCLEUS, 0103 physical sciences, PHYSICS PROCESSES, Statistical physics, High energy physics, Adaptation (computer science), Instrumentation, QC, Computing, Radiation, Simulation, ComputingMilieux_MISCELLANEOUS, Nuclear and High Energy Physic, Physics, Physics::Computational Physics, 010308 nuclear & particles physics, business.industry, Detector, NUCLEUS CROSS-SECTIONS, SPACE EVENT GENERATOR, Variety (cybernetics), Visualization, Computing and Computers, MICRODOSIMETRY SIMULATION, Nuclear physic, Multithreading, Nuclear Physics - Theory, Systems engineering, Space Science, business
Abstract

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 835, ISSN:0168-9002, ISSN:1872-9576

Published
2016
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14. Towards Optimal Collimator Design for the PEDRO Hybrid Imaging System

Author

Jeremy M. C. Brown, David V. Martin, Dmitri A. Nikulin, Matthew Richard Dimmock, Chuong Nguyen, and John E. Gillam

Subjects
Physics, Nuclear and High Energy Physics, business.industry, Monte Carlo method, Detector, Compton scattering, Collimator, law.invention, Optics, Nuclear Energy and Engineering, Sampling (signal processing), law, Position (vector), Electrical and Electronic Engineering, Photonics, business, Image resolution
Abstract

The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imaging system designed for the measurement of single photon emission from small animal models. The proof-of-principle device consists of a Compton-camera situated behind a mechanical collimator and is intended to provide optimal detection characteristics over a broad spectral range, from 30 to 511 keV. An automated routine has been developed for the optimization of large-area slits in the outer regions of a collimator which has a central region allocated for pinholes. The optimization was tested with a GEANT4 model of the experimental prototype. The data were blurred with the expected position and energy resolution parameters and a Bayesian interaction ordering algorithm was applied. Images were reconstructed using cone back-projection. The results show that the optimization technique allows the large-area slits to both sample fully and extend the primary field of view (FoV) determined by the pinholes. The slits were found to provide truncation of the back-projected cones of response and also an increase in the success rate of the interaction ordering algorithm. These factors resulted in an increase in the contrast and signal-to-noise ratio of the reconstructed image estimates. Of the two configurations tested, the cylindrical geometry outperformed the square geometry, primarily because of a decrease in artifacts. This was due to isotropic modulation of the cone surfaces, that can be achieved with a circular shape. Also, the cylindrical geometry provided increased sampling of the FoV due to more optimal positioning of the slits. The use of the cylindrical collimator and application of the transmission function in the reconstruction was found to improve the resolution of the system by a factor of 20, as compared to the uncollimated Compton camera. Although this system is designed for small animal imaging, the technique can be applied to any application of single photon imaging.

Published
2011
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15. A Pixelated Emission Detector for RadiOisotopes (PEDRO)

Author

Chris Hall, Robert A. Lewis, John E. Gillam, Jeremy M. C. Brown, Matthew Richard Dimmock, and Toby Ean Beveridge

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), medicine.diagnostic_test, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Resolution (electron density), Detector, Gauge (firearms), Collimated light, Optics, medicine, Tomography, business, Instrumentation, Sensitivity (electronics), Emission computed tomography
Abstract

The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imager designed for the measurement of single photon emission from small animals. The proof-of-principle device currently under development consists of a Compton-camera situated behind a mechanical modulator. The combination of mechanical and electronic (hybrid) collimation should provide optimal detection characteristics over a broad spectral range ( 30 keV ≤ E γ ≤ 511 keV ) , through a reduction in the sensitivity-resolution trade-off, inherent in conventional mechanically collimated configurations. This paper presents GEANT4 simulation results from the PEDRO geometry operated only as a Compton camera in order to gauge its advantage when used in concert with mechanical collimation—regardless of the collimation pattern. The optimization of multiple detector spacing and resolution parameters is performed utilizing the Median Distance of Closest Approach (MDCA) and has been shown to result in an optimum distance, beyond which only a loss in sensitivity occurs.

Published
2009
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16. Track structure modeling in liquid water: A review of the Geant4-DNA very low energy extension of the Geant4 Monte Carlo simulation toolkit

Author

K. Murakami, Susanna Guatelli, Vladimir Ivanchenko, Takashi Sasaki, Jeremy M. C. Brown, Ioanna Kyriakou, E. Delage, Mario A. Bernal, H. Payno, Marie-Claude Bordage, Ivan Petrović, Sylvain Meylan, Q.T. Pham, Aleksandra Ristić-Fira, Shirin A. Enger, Yann Perrot, Ziad Francis, Václav Štěpán, Shogo Okada, Z. El Bitar, M. Karamitros, Carmen Villagrasa, Lydia Maigne, Sebastien Incerti, Marie Davídková, H.N. Tran, Instituto de Fisica 'Gleb Wataghin', Universidade Estadual de Campinas (UNICAMP), Centre de Recherches en Cancérologie de Toulouse (CRCT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), School of Mathematics and Physics [Belfast], Queen's University [Belfast] (QUB), School of Physics and Astronomy [Clayton], Monash University [Clayton], Department of Radiation Dosimetry, Nuclear Physics Institute of the AS CR, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Medical Physics Unit, Department of Oncology, McGill University = Université McGill [Montréal, Canada], Department of Physics, Faculty of Sciences, Université Saint-Joseph de Beyrouth (USJ), Centre for Medical Radiation Physics, University of Wollongong [Australia], Geant4 Associates International Ltd, Ecoanalytica, Notre Dame Radiation Laboratory, University of Notre Dame [Indiana] (UND), Medical Physics Laboratory, Medical School University of Ioannina, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), KEK (High energy accelerator research organization), Vinča Institute of Nuclear Sciences, University of Belgrade [Belgrade], Division of Nuclear Physics, Tong Duc Thang University, Faculty of Applied Sciences, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Nuclear Physics Institute of the ASCR, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), McGill University, University of Wollongong, High Energy Accelerator Research Organization (KEK), University of Tsukuba, Universidade Estadual de Campinas = University of Campinas (UNICAMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), University of Ioannina, and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Models, Molecular, Chemical process, Ionizing radiation, Chemical Phenomena, Stochastic modelling, Liquid water, Monte Carlo method, Biophysics, General Physics and Astronomy, Track (rail transport), Radiolysis, Humans, Radiology, Nuclear Medicine and imaging, Monte Carlo, Simulation, Physics, Structure (mathematical logic), Physical model, Geant4-DNA, Water, Radiobiology, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, DNA, General Medicine, Extension (predicate logic), [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Systems engineering, Monte Carlo Method
Abstract

International audience; Understanding the fundamental mechanisms involved in the induction of biological damage by ionizing radiation remains a major challenge of today's radiobiology research. The Monte Carlo simulation of physical, physicochemical and chemical processes involved may provide a powerful tool for the simulation of early damage induction. The Geant4-DNA extension of the general purpose Monte Carlo Geant4 simulation toolkit aims to provide the scientific community with an open source access platform for the mechanistic simulation of such early damage. This paper presents the most recent review of the Geant4-DNA extension, as available to Geant4 users since June 2015 (release 10.2 Beta). In particular, the review includes the description of new physical models for the description of electron elastic and inelastic interactions in liquid water, as well as new examples dedicated to the simulation of physicochemical and chemical stages of water radiolysis. Several implementations of geometrical models of biological targets are presented as well, and the list of Geant4-DNA examples is described.

Published
2015
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17. Progress in Geant4 Electromagnetic Physics Modelling and Validation

Author

Luciano Pandola, Sebastien Incerti, John Apostolakis, M. Asai, J. Jacquemier, T Yamashita, Helmut Burkhardt, Toshiyuki Toshito, M. A. Cortés-Giraldo, Vladimir Ivanchenko, Jeremy M. C. Brown, M. Maire, S Elles, O Kadri, L. Urbán, Vladimir Grichine, Susanna Guatelli, Alexander Bagulya, D Sawkey, N Chikuma, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), GEANT4, and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear

Subjects
Physics, History, Work (thermodynamics), BREMSSTRAHLUNG, Large Hadron Collider, Muon, Scattering, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Compton scattering, Synchrotron radiation, Electron, Photoelectric effect, 7. Clean energy, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Computer Science Applications, Education, Computing and Computers, Nuclear physics, TARGETS, SIMULATION
Abstract

Journal of Physics: Conference Series In this work we report on recent improvements in the electromagnetic (EM) physics models of Geant4 and new validations of EM physics. Improvements have been made in models of the photoelectric effect, Compton scattering, gamma conversion to electron and muon pairs, fluctuations of energy loss, multiple scattering, synchrotron radiation, and high energy positron annihilation. The results of these developments are included in the new Geant4 version 10.1 and in patches to previous versions 9.6 and 10.0 that are planned to be used for production for run-2 at LHC. The Geant4 validation suite for EM physics has been extended and new validation results are shown in this work. In particular, the effect of gamma-nuclear interactions on EM shower shape at LHC energies is discussed.

Published
2015
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18. Validation of a Geant4 model of the X-ray fluorescence microprobe at the Australian Synchrotron

Author

David J. Paterson, David M. Paganin, Daryl L. Howard, Simon James, Matthew Richard Dimmock, Jeremy M. C. Brown, R. Kirkham, Gary Ruben, Chris Ryan, and Martin D. de Jonge

Subjects
Physics, Nuclear and High Energy Physics, Microprobe, Radiation, business.industry, Monte Carlo method, Compton scattering, X-ray fluorescence, Spectral line, Synchrotron, law.invention, Computational physics, Optics, law, business, Australian Synchrotron, Instrumentation, Gaussian beam
Abstract

AGeant4Monte Carlo simulation of the X-ray fluorescence microprobe (XFM) end-station at the Australian Synchrotron has been developed. The simulation is required for optimization of the scan configuration and reconstruction algorithms. As part of the simulation process, a Gaussian beam model was developed. Experimental validation of this simulation has tested the efficacy for use of the low-energy physics models inGeant4for this synchrotron-based technique. The observed spectral distributions calculated in the 384 pixel Maia detector, positioned in the standard back-scatter configuration, were compared with those obtained from experiments performed at three incident X-ray beam energies: 18.5, 11.0 and 6.8 keV. The reduced χ-squared (\chi^{2}_{\rm{red}}) was calculated for the scatter and fluorescence regions of the spectra and demonstrates that the simulations successfully reproduce the scatter distributions. Discrepancies were shown to occur in the multiple-scatter tail of the Compton continuum. The model was shown to be particularly sensitive to the impurities present in the beryllium window of the Maia detector and their concentrations were optimized to improve the \chi^{2}_{\rm{red}} parameterization in the low-energy fluorescence regions of the spectra.

Published
2014

19. Comparison of Geant4-DNA simulation of S-values with other Monte Carlo codes

Author

Mario A. Bernal, C. Le Loirec, Manuel Bardiès, Ph. Barberet, L. Campos, C. Zacharatou, Marie-Claude Bordage, Jeremy M. C. Brown, M. Karamitros, Yann Perrot, Filippo Morini, Michel Fromm, B. Mascialino, Ziad Francis, Christophe Champion, Michael S. Deleuze, Vladimir Ivanchenko, T. André, J.-E. Groetz, R. Delorme, Sebastien Incerti, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Hasselt University (UHasselt), Institut de Neurosciences cognitives et intégratives d'Aquitaine (INCIA), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-SFR Bordeaux Neurosciences-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Laboratoire Modélisation et Simulation de Systèmes (LM2S), Département Métrologie Instrumentation & Information (DM2I), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Monash University [Melbourne], Institut Bergonié [Bordeaux], UNICANCER, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), supported by the INSERM PhysiCancer 'MICRONAUTE' project (2013–2014)., Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-SFR Bordeaux Neurosciences-Centre National de la Recherche Scientifique (CNRS), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire d'Intégration des Systèmes et des Technologies (LIST), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Hasselt University, Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Technologique (CEA) (DRT (CEA)), Laboratoire Chrono-environnement - UFC (UMR 6249) (LCE), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Institut Bergonié - CRLCC Bordeaux, Centre d'Etudes Nucléaires de Bordeaux Gradignan ( CENBG ), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Interface Physique et Chimie pour le Vivant ( IPCV ), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique Subatomique et de Cosmologie ( LPSC ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Laboratoire de Physique Corpusculaire - Clermont-Ferrand ( LPC ), and Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Physics, Nuclear and High Energy Physics, [STAT.AP]Statistics [stat]/Applications [stat.AP], Geant4-DNA, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Monte Carlo method, Elementary particle, Fermion, Electron, Radius, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, 030218 nuclear medicine & medical imaging, Computational physics, 03 medical and health sciences, 0302 clinical medicine, Isotopes of iodine, Liquid water, 030220 oncology & carcinogenesis, S-values, [ PHYS.PHYS.PHYS-MED-PH ] Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], SPHERES, Statistical physics, Instrumentation, Monte Carlo, Lepton
Abstract

Monte Carlo simulations of S-values have been carried out with the Geant4-DNA extension of the Geant4 toolkit. The S-values have been simulated for monoenergetic electrons with energies ranging from 0.1 keV up to 20 keV, in liquid water spheres (for four radii, chosen between 10 nm and 1 μm), and for electrons emitted by five isotopes of iodine (131, 132, 133, 134 and 135), in liquid water spheres of varying radius (from 15 μm up to 250 μm). The results have been compared to those obtained from other Monte Carlo codes and from other published data. The use of the Kolmogorov–Smirnov test has allowed confirming the statistical compatibility of all simulation results.

Published
2014
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20. MULECS: The Monash University Low Energy Compton scattering package

Author

Jeremy M. C. Brown, John E. Gillam, David M. Paganin, and Matthew Richard Dimmock

Subjects
Physics, Range (particle radiation), Scattering, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Compton scattering, Electron, Inelastic scattering, Computational physics, Momentum, Optics, business, Doppler broadening
Abstract

Monte Carlo based radiation transport modelling is a useful tool in evaluating the interaction and effect of radiation in a defined environment. The process of simulating Compton scattering is of interest in a large number of different fields. Of the range of available Monte Carlo radiation transport programs, Geant4, one of the most popular, integrated the effects of Doppler broadening into their standard low energy Compton scattering package in 2008. However, there still exists a significant limitation within this standard Compton scattering package regarding the algorithms that determine the emission direction of Compton electrons. Here we outline the development of the Monash University Low Energy Compton Scattering (MULECS) package. The package addresses the current limitation of Compton electron directionality of Geant4 through the inclusion of additional directional information of the pre-collision momentum. MULECS is intended to replace the standard Compton scattering package of Geant4 to improve the accuracy of emission imaging simulations below 2 MeV.

Published
2011
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21. Hybrid-collimator design for a small animal imager: PEDRO

Author

Robert A. Lewis, John E. Gillam, Jeremy M. C. Brown, David V. Martin, Chuong Nguyen, Matthew Richard Dimmock, and Dmitri A. Nikulin

Subjects
Physics, business.industry, Detector, Collimator, Iterative reconstruction, Sample (graphics), law.invention, Optics, Position (vector), law, Truncation (statistics), Photonics, business, Energy (signal processing)
Abstract

The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imaging system designed for the measurement of single photon emission from small animal models. The proof-of-principle device consists of a Compton-camera situated behind a mechanical collimator and is intended to provide optimal detection characteristics over a broad spectral range, from 30 keV to 511 keV. An automated routine has been developed for the optimization of the mechanical collimator which consists of pinholes and open slits. The optimization was tested with a Geant4 model of the experimental prototype. The data were blurred with the expected position and energy resolution parameters and a Bayesian interaction ordering algorithm was applied. The results show that the optimization technique allows the large-area slits to sample fully the primary field of view (FoV). The slits were found to provide truncation of the back-projected cones of response and also an increase in the success rate of the interaction ordering algorithm. These factors resulted in an increase in the contrast and signal-to-noise ratios of the reconstructed image estimates.

Published
2010
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