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Sample records for geant4 software design

  1. First statistical analysis of Geant4 quality software metrics

    NASA Astrophysics Data System (ADS)

    Ronchieri, Elisabetta; Grazia Pia, Maria; Giacomini, Francesco

    2015-12-01

    Geant4 is a simulation system of particle transport through matter, widely used in several experimental areas from high energy physics and nuclear experiments to medical studies. Some of its applications may involve critical use cases; therefore they would benefit from an objective assessment of the software quality of Geant4. In this paper, we provide a first statistical evaluation of software metrics data related to a set of Geant4 physics packages. The analysis aims at identifying risks for Geant4 maintainability, which would benefit from being addressed at an early stage. The findings of this pilot study set the grounds for further extensions of the analysis to the whole of Geant4 and to other high energy physics software systems.

  2. The GEANT4 Visualisation System

    SciTech Connect

    Allison, J.; Asai, M.; Barrand, G.; Donszelmann, M.; Minamimoto, K.; Tanaka, S.; Tcherniaev, E.; Tinslay, J.; /SLAC

    2007-11-02

    The Geant4 Visualization System is a multi-driver graphics system designed to serve the Geant4 Simulation Toolkit. It is aimed at the visualization of Geant4 data, primarily detector descriptions and simulated particle trajectories and hits. It can handle a variety of graphical technologies simultaneously and interchangeably, allowing the user to choose the visual representation most appropriate to requirements. It conforms to the low-level Geant4 abstract graphical user interfaces and introduces new abstract classes from which the various drivers are derived and that can be straightforwardly extended, for example, by the addition of a new driver. It makes use of an extendable class library of models and filters for data representation and selection. The Geant4 Visualization System supports a rich set of interactive commands based on the Geant4 command system. It is included in the Geant4 code distribution and maintained and documented like other components of Geant4.

  3. MCNP5 and GEANT4 comparisons for preliminary Fast Neutron Pencil Beam design at the University of Utah TRIGA system

    NASA Astrophysics Data System (ADS)

    Adjei, Christian Amevi

    The main objective of this thesis is twofold. The starting objective was to develop a model for meaningful benchmarking of different versions of GEANT4 against an experimental set-up and MCNP5 pertaining to photon transport and interactions. The following objective was to develop a preliminary design of a Fast Neutron Pencil Beam (FNPB) Facility to be applicable for the University of Utah research reactor (UUTR) using MCNP5 and GEANT4. The three various GEANT4 code versions, GEANT4.9.4, GEANT4.9.3, and GEANT4.9.2, were compared to MCNP5 and the experimental measurements of gamma attenuation in air. The average gamma dose rate was measured in the laboratory experiment at various distances from a shielded cesium source using a Ludlum model 19 portable NaI detector. As it was expected, the gamma dose rate decreased with distance. All three GEANT4 code versions agreed well with both the experimental data and the MCNP5 simulation. Additionally, a simple GEANT4 and MCNP5 model was developed to compare the code agreements for neutron interactions in various materials. Preliminary FNPB design was developed using MCNP5; a semi-accurate model was developed using GEANT4 (because GEANT4 does not support the reactor physics modeling, the reactor was represented as a surface neutron source, thus a semi-accurate model). Based on the MCNP5 model, the fast neutron flux in a sample holder of the FNPB is obtained to be 6.52×107 n/cm2s, which is one order of magnitude lower than gigantic fast neutron pencil beam facilities existing elsewhere. The MCNP5 model-based neutron spectrum indicates that the maximum expected fast neutron flux is at a neutron energy of ~1 MeV. In addition, the MCNP5 model provided information on gamma flux to be expected in this preliminary FNPB design; specifically, in the sample holder, the gamma flux is to be expected to be around 108 γ/cm 2s, delivering a gamma dose of 4.54×103 rem/hr. This value is one to two orders of magnitudes below the gamma

  4. Simulation of neutron production in heavy metal targets using Geant4 software

    NASA Astrophysics Data System (ADS)

    Baldin, A. A.; Berlev, A. I.; Kudashkin, I. V.; Mogildea, G.; Mogildea, M.; Paraipan, M.; Tyutyunnikov, S. I.

    2016-03-01

    Inelastic hadronic interactions in heavy targets have been simulated using Geant4 and compared with experimental data for thin and thick lead and uranium targets. Special attention is paid to neutron and fission fragment production. Good agreement in the description of proton-beam interaction with thick targets is demonstrated, which is important for the simulation of experiments aimed at the development of subcritical reactors.

  5. Geant4 Applications in Space

    SciTech Connect

    Asai, M.; /SLAC

    2007-11-07

    Use of Geant4 is rapidly expanding in space application domain. I try to overview three major application areas of Geant4 in space, which are apparatus simulation for pre-launch design and post-launch analysis, planetary scale simulation for radiation spectra and surface and sub-surface explorations, and micro-dosimetry simulation for single event study and radiation-hardening of semiconductor devices. Recently, not only the mission dependent applications but also various multi-purpose or common tools built on top of Geant4 are also widely available. I overview some of such tools as well. The Geant4 Collaboration identifies that the space applications are now one of the major driving forces of the further developments and refinements of Geant4 toolkit. Highlights of such developments are introduced.

  6. GEANT4 Applications in Space

    NASA Astrophysics Data System (ADS)

    Asai, Makoto

    2008-06-01

    The use of Geant4 is rapidly expanding in the domain of space applications. I try to give an overview three major application areas of Geant4 in space, which are apparatus simulation for pre-launch design and post-launch analysis, planetary scale simulation for radiation spectra and surface and sub-surface explorations, and micro-dosimetry simulation for single event study and radiation-hardening of semiconductor devices. Recently, not only the mission-dependent applications but also various multi-purpose or common tools built on top of Geant4 are also widely available. I overview some of these tools as well. The Geant4 Collaboration identifies the space applications now-as one of the major driving forces of the further developments and refinements of Geant4 toolkit. Highlights of such developments are given.

  7. GEANT4 used for neutron beam design of a neutron imaging facility at TRIGA reactor in Morocco

    NASA Astrophysics Data System (ADS)

    Ouardi, A.; Machmach, A.; Alami, R.; Bensitel, A.; Hommada, A.

    2011-09-01

    Neutron imaging has a broad scope of applications and has played a pivotal role in visualizing and quantifying hydrogenous masses in metallic matrices. The field continues to expand into new applications with the installation of new neutron imaging facilities. In this scope, a neutron imaging facility for computed tomography and real-time neutron radiography is currently being developed around 2.0MW TRIGA MARK-II reactor at Maamora Nuclear Research Center in Morocco (Reuscher et al., 1990 [1]; de Menezes et al., 2003 [2]; Deinert et al., 2005 [3]). The neutron imaging facility consists of neutron collimator, real-time neutron imaging system and imaging process systems. In order to reduce the gamma-ray content in the neutron beam, the tangential channel was selected. For power of 250 kW, the corresponding thermal neutron flux measured at the inlet of the tangential channel is around 3×10 11 ncm 2/s. This facility will be based on a conical neutron collimator with two circular diaphragms with diameters of 4 and 2 cm corresponding to L/D-ratio of 165 and 325, respectively. These diaphragms' sizes allow reaching a compromise between good flux and efficient L/D-ratio. Convergent-divergent collimator geometry has been adopted. The beam line consists of a gamma filter, fast neutrons filter, neutron moderator, neutron and gamma shutters, biological shielding around the collimator and several stages of neutron collimator. Monte Carlo calculations by a fully 3D numerical code GEANT4 were used to design the neutron beam line ( http://www.info.cern.ch/asd/geant4/geant4.html[4]). To enhance the neutron thermal beam in terms of quality, several materials, mainly bismuth (Bi) and sapphire (Al 2O 3) were examined as gamma and neutron filters respectively. The GEANT4 simulations showed that the gamma and epithermal and fast neutron could be filtered using the bismuth (Bi) and sapphire (Al 2O 3) filters, respectively. To get a good cadmium ratio, GEANT 4 simulations were used to

  8. Recent Developments in the Geant4 Hadronic Framework

    NASA Astrophysics Data System (ADS)

    Pokorski, Witold; Ribon, Alberto

    2014-06-01

    In this paper we present the recent developments in the Geant4 hadronic framework. Geant4 is the main simulation toolkit used by the LHC experiments and therefore a lot of effort is put into improving the physics models in order for them to have more predictive power. As a consequence, the code complexity increases, which requires constant improvement and optimization on the programming side. At the same time, we would like to review and eventually reduce the complexity of the hadronic software framework. As an example, a factory design pattern has been applied in Geant4 to avoid duplications of objects, like cross sections, which can be used by several processes or physics models. This approach has been applied also for physics lists, to provide a flexible configuration mechanism at run-time, based on macro files. Moreover, these developments open the future possibility to build Geant4 with only a specified sub-set of physics models. Another technical development focused on the reproducibility of the simulation, i.e. the possibility to repeat an event once the random generator status at the beginning of the event is known. This is crucial for debugging rare situations that may occur after long simulations. Moreover, reproducibility in normal, sequential Geant4 simulation is an important prerequisite to verify the equivalence with multithreaded Geant4 simulations.

  9. A Virtual Geant4 Environment

    NASA Astrophysics Data System (ADS)

    Iwai, Go

    2015-12-01

    We describe the development of an environment for Geant4 consisting of an application and data that provide users with a more efficient way to access Geant4 applications without having to download and build the software locally. The environment is platform neutral and offers the users near-real time performance. In addition, the environment consists of data and Geant4 libraries built using low-level virtual machine (LLVM) tools which can produce bitcode that can be embedded in HTML and accessed via a browser. The bitcode is downloaded to the local machine via the browser and can then be configured by the user. This approach provides a way of minimising the risk of leaking potentially sensitive data used to construct the Geant4 model and application in the medical domain for treatment planning. We describe several applications that have used this approach and compare their performance with that of native applications. We also describe potential user communities that could benefit from this approach.

  10. Design of Cherenkov bars for the optical part of the time-of-flight detector in Geant4.

    PubMed

    Nozka, L; Brandt, A; Rijssenbeek, M; Sykora, T; Hoffman, T; Griffiths, J; Steffens, J; Hamal, P; Chytka, L; Hrabovsky, M

    2014-11-17

    We present the results of studies devoted to the development and optimization of the optical part of a high precision time-of-flight (TOF) detector for the Large Hadron Collider (LHC). This work was motivated by a proposal to use such a detector in conjunction with a silicon detector to tag and measure protons from interactions of the type p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The fast timing detector uses fused silica (quartz) bars that emit Cherenkov radiation as a relativistic particle passes through and the emitted Cherenkov photons are detected by, for instance, a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT). Several possible designs are implemented in Geant4 and studied for timing optimization as a function of the arrival time, and the number of Cherenkov photons reaching the photo-sensor. PMID:25402137

  11. A CAD interface for GEANT4.

    PubMed

    Poole, C M; Cornelius, I; Trapp, J V; Langton, C M

    2012-09-01

    Often CAD models already exist for parts of a geometry being simulated using GEANT4. Direct import of these CAD models into GEANT4 however, may not be possible and complex components may be difficult to define via other means. Solutions that allow for users to work around the limited support in the GEANT4 toolkit for loading predefined CAD geometries have been presented by others, however these solutions require intermediate file format conversion using commercial software. Here within we describe a technique that allows for CAD models to be directly loaded as geometry without the need for commercial software and intermediate file format conversion. Robustness of the interface was tested using a set of CAD models of various complexity; for the models used in testing, no import errors were reported and all geometry was found to be navigable by GEANT4. PMID:22956356

  12. Simulations of nuclear resonance fluorescence in GEANT4

    NASA Astrophysics Data System (ADS)

    Lakshmanan, Manu N.; Harrawood, Brian P.; Rusev, Gencho; Agasthya, Greeshma A.; Kapadia, Anuj J.

    2014-11-01

    The nuclear resonance fluorescence (NRF) technique has been used effectively to identify isotopes based on their nuclear energy levels. Specific examples of its modern-day applications include detecting spent nuclear waste and cargo scanning for homeland security. The experimental designs for these NRF applications can be more efficiently optimized using Monte Carlo simulations before the experiment is implemented. One of the most widely used Monte Carlo physics simulations is the open-source toolkit GEANT4. However, NRF physics has not been incorporated into the GEANT4 simulation toolkit in publicly available software. Here we describe the development and testing of an NRF simulation in GEANT4. We describe in depth the development and architecture of this software for the simulation of NRF in any isotope in GEANT4; as well as verification and validation testing of the simulation for NRF in boron. In the verification testing, the simulation showed agreement with the analytical model to be within 0.6% difference for boron and iron. In the validation testing, the simulation showed agreement to be within 20.5% difference with the experimental measurements for boron, with the percent difference likely due to small uncertainties in beam polarization, energy distribution, and detector composition.

  13. Designing a new type of neutron detector for neutron and gamma-ray discrimination via GEANT4.

    PubMed

    Shan, Qing; Chu, Shengnan; Ling, Yongsheng; Cai, Pingkun; Jia, Wenbao

    2016-04-01

    Design of a new type of neutron detector, consisting of a fast neutron converter, plastic scintillator, and Cherenkov detector, to discriminate 14-MeV fast neutrons and gamma rays in a pulsed n-γ mixed field and monitor their neutron fluxes is reported in this study. Both neutrons and gamma rays can produce fluorescence in the scintillator when they are incident on the detector. However, only the secondary charged particles of the gamma rays can produce Cherenkov light in the Cherenkov detector. The neutron and gamma-ray fluxes can be calculated by measuring the fluorescence and Cherenkov light. The GEANT4 Monte Carlo simulation toolkit is used to simulate the whole process occurring in the detector, whose optimum parameters are known. Analysis of the simulation results leads to a calculation method of neutron flux. This method is verified by calculating the neutron fluxes using pulsed n-γ mixed fields with different n/γ ratios, and the results show that the relative errors of all calculations are <5%. PMID:26844541

  14. GEANT4-MT : bringing multi-threading into GEANT4 production

    NASA Astrophysics Data System (ADS)

    Ahn, Sunil; Apostolakis, John; Asai, Makoto; Brandt, Daniel; Cooperman, Gene; Cosmo, Gabriele; Dotti, Andrea; Dong, Xin; Jun, Soon Yung; Nowak, Andrzej

    2014-06-01

    GEANT4-MT is the multi-threaded version of the GEANT4 particle transport code.(1, 2) The key goals for the design of GEANT4-MT have been a) the need to reduce the memory footprint of the multi-threaded application compared to the use of separate jobs and processes; b) to create an easy migration of the existing applications; and c) to use efficiently many threads or cores, by scaling up to tens and potentially hundreds of workers. The first public release of a GEANT4-MT prototype was made in 2011. We report on the revision of GEANT4-MT for inclusion in the production-level release scheduled for end of 2013. This has involved significant re-engineering of the prototype in order to incorporate it into the main GEANT4 development line, and the porting of GEANT4-MT threading code to additional platforms. In order to make the porting of applications as simple as possible, refinements addressed the needs of standalone applications. Further adaptations were created to improve the fit with the frameworks of High Energy Physics (HEP) experiments. We report on performances measurements on Intel Xeon™, AMD Opteron™ the first trials of GEANT4-MT on the Intel Many Integrated Cores (MIC) architecture, in the form of the Xeon Phi™ co-processor.(3) These indicate near-linear scaling through about 200 threads on 60 cores, when holding fixed the number of events per thread.

  15. Geant4 software application for the simulation of cosmic ray showers in the Earth’s atmosphere

    NASA Astrophysics Data System (ADS)

    Paschalis, P.; Mavromichalaki, H.; Dorman, L. I.; Plainaki, C.; Tsirigkas, D.

    2014-11-01

    Galactic cosmic rays and solar energetic particles with sufficient rigidity to penetrate the geomagnetic field, enter the Earth’s atmosphere and interact with the electrons and the nuclei of its atoms and molecules. From the interactions with the nuclei, cascades of secondary particles are produced that can be detected by ground-based detectors such as neutron monitors and muon counters. The theoretical study of the details of the atmospheric showers is of great importance, since many applications, such as the dosimetry for the aviation crews, are based on it. In this work, a new application which can be used in order to study the showers of the secondary particles in the atmosphere is presented. This application is based on the Monte Carlo simulation techniques, performed by using the well-known Geant4 toolkit. We present a thorough analysis of the simulation’s critical points, including a description of the procedure applied in order to model the atmosphere and the geomagnetic field. Representative results obtained by the application are presented and future plans for the project are discussed.

  16. Geant4 - Towards major release 10

    NASA Astrophysics Data System (ADS)

    Cosmo, G.; Geant4 Collaboration

    2014-06-01

    The Geant4 simulation toolkit has reached maturity in the middle of the previous decade, providing a wide variety of established features coherently aggregated in a software product, which has become the standard for detector simulation in HEP and is used in a variety of other application domains. We review the most recent capabilities introduced in the kernel, highlighting those, which are being prepared for the next major release (version 10.0) that is scheduled for the end of 2013. A significant new feature contained in this release will be the integration of multi-threading processing, aiming at targeting efficient use of modern many-cores system architectures and minimization of the memory footprint for exploiting event-level parallelism. We discuss its design features and impact on the existing API and user-interface of Geant4. Revisions are made to balance the need for preserving backwards compatibility and to consolidate and improve the interfaces; taking into account requirements from the multithreaded extensions and from the evolution of the data processing models of the LHC experiments.

  17. GEANT4: Applications in High Energy Physics

    SciTech Connect

    Mahmood, Tariq; Zafar, Abrar Ahmed; Hussain, Talib; Rashid, Haris

    2007-02-14

    GEANT4 is a detector simulation toolkit aimed at studying, mainly experimental high energy physics. In this paper we will give an overview of this software with special reference to its applications in high energy physics experiments. A brief of process methods is given. Object-oriented nature of the simulation toolkit is highlighted.

  18. GAMOS: A framework to do GEANT4 simulations in different physics fields with an user-friendly interface

    NASA Astrophysics Data System (ADS)

    Arce, Pedro; Ignacio Lagares, Juan; Harkness, Laura; Pérez-Astudillo, Daniel; Cañadas, Mario; Rato, Pedro; de Prado, María; Abreu, Yamiel; de Lorenzo, Gianluca; Kolstein, Machiel; Díaz, Angelina

    2014-01-01

    GAMOS is a software system for GEANT4-based simulation. It comprises a framework, a set of components providing functionality to simulation applications on top of the GEANT4 toolkit, and a collection of ready-made applications. It allows to perform GEANT4-based simulations using a scripting language, without requiring the writing of C++ code. Moreover, GAMOS design allows the extension of the existing functionality through user-supplied C++ classes. The main characteristics of GAMOS and its embedded functionality are described.

  19. Geant4 Computing Performance Benchmarking and Monitoring

    SciTech Connect

    Dotti, Andrea; Elvira, V. Daniel; Folger, Gunter; Genser, Krzysztof; Jun, Soon Yung; Kowalkowski, James B.; Paterno, Marc

    2015-12-23

    Performance evaluation and analysis of large scale computing applications is essential for optimal use of resources. As detector simulation is one of the most compute intensive tasks and Geant4 is the simulation toolkit most widely used in contemporary high energy physics (HEP) experiments, it is important to monitor Geant4 through its development cycle for changes in computing performance and to identify problems and opportunities for code improvements. All Geant4 development and public releases are being profiled with a set of applications that utilize different input event samples, physics parameters, and detector configurations. Results from multiple benchmarking runs are compared to previous public and development reference releases to monitor CPU and memory usage. Observed changes are evaluated and correlated with code modifications. Besides the full summary of call stack and memory footprint, a detailed call graph analysis is available to Geant4 developers for further analysis. The set of software tools used in the performance evaluation procedure, both in sequential and multi-threaded modes, include FAST, IgProf and Open|Speedshop. In conclusion, the scalability of the CPU time and memory performance in multi-threaded application is evaluated by measuring event throughput and memory gain as a function of the number of threads for selected event samples.

  20. Geant4 Computing Performance Benchmarking and Monitoring

    NASA Astrophysics Data System (ADS)

    Dotti, Andrea; Elvira, V. Daniel; Folger, Gunter; Genser, Krzysztof; Jun, Soon Yung; Kowalkowski, James B.; Paterno, Marc

    2015-12-01

    Performance evaluation and analysis of large scale computing applications is essential for optimal use of resources. As detector simulation is one of the most compute intensive tasks and Geant4 is the simulation toolkit most widely used in contemporary high energy physics (HEP) experiments, it is important to monitor Geant4 through its development cycle for changes in computing performance and to identify problems and opportunities for code improvements. All Geant4 development and public releases are being profiled with a set of applications that utilize different input event samples, physics parameters, and detector configurations. Results from multiple benchmarking runs are compared to previous public and development reference releases to monitor CPU and memory usage. Observed changes are evaluated and correlated with code modifications. Besides the full summary of call stack and memory footprint, a detailed call graph analysis is available to Geant4 developers for further analysis. The set of software tools used in the performance evaluation procedure, both in sequential and multi-threaded modes, include FAST, IgProf and Open|Speedshop. The scalability of the CPU time and memory performance in multi-threaded application is evaluated by measuring event throughput and memory gain as a function of the number of threads for selected event samples.

  1. Geant4 Computing Performance Benchmarking and Monitoring

    DOE PAGESBeta

    Dotti, Andrea; Elvira, V. Daniel; Folger, Gunter; Genser, Krzysztof; Jun, Soon Yung; Kowalkowski, James B.; Paterno, Marc

    2015-12-23

    Performance evaluation and analysis of large scale computing applications is essential for optimal use of resources. As detector simulation is one of the most compute intensive tasks and Geant4 is the simulation toolkit most widely used in contemporary high energy physics (HEP) experiments, it is important to monitor Geant4 through its development cycle for changes in computing performance and to identify problems and opportunities for code improvements. All Geant4 development and public releases are being profiled with a set of applications that utilize different input event samples, physics parameters, and detector configurations. Results from multiple benchmarking runs are compared tomore » previous public and development reference releases to monitor CPU and memory usage. Observed changes are evaluated and correlated with code modifications. Besides the full summary of call stack and memory footprint, a detailed call graph analysis is available to Geant4 developers for further analysis. The set of software tools used in the performance evaluation procedure, both in sequential and multi-threaded modes, include FAST, IgProf and Open|Speedshop. In conclusion, the scalability of the CPU time and memory performance in multi-threaded application is evaluated by measuring event throughput and memory gain as a function of the number of threads for selected event samples.« less

  2. Geant4 VMC 3.0

    NASA Astrophysics Data System (ADS)

    Hřivnáčová, I.; Gheata, A.

    2015-12-01

    Virtual Monte Carlo (VMC) [1] provides an abstract interface into Monte Carlo transport codes. A user VMC based application, independent from the specific Monte Carlo codes, can be then run with any of the supported simulation programs. Developed by the ALICE Offline Project and further included in ROOT [2], the interface and implementations have reached stability during the last decade and have become a foundation for other detector simulation frameworks, the FAIR facility experiments framework being among the first and largest. Geant4 VMC [3], which provides the implementation of the VMC interface for Geant4 [4], is in continuous maintenance and development, driven by the evolution of Geant4 on one side and requirements from users on the other side. Besides the implementation of the VMC interface, Geant4 VMC also provides a set of examples that demonstrate the use of VMC to new users and also serve for testing purposes. Since major release 2.0, it includes the G4Root navigator package, which implements an interface that allows one to run a Geant4 simulation using a ROOT geometry. The release of Geant4 version 10.00 with the integration of multithreading processing has triggered the development of the next major version of Geant4 VMC (version 3.0), which was released in November 2014. A beta version, available for user testing since March, has helped its consolidation and improvement. We will review the new capabilities introduced in this major version, in particular the integration of multithreading into the VMC design, its impact on the Geant4 VMC and G4Root packages, and the introduction of a new package, MTRoot, providing utility functions for ROOT parallel output in independent files with necessary additions for thread-safety. Migration of user applications to multithreading that preserves the ease of use of VMC will be also discussed. We will also report on the introduction of a new CMake [5] based build system, the migration to ROOT major release 6 and the

  3. The Cryogenic AntiCoincidence Detector for the ATHENA X-IFU: Design Aspects by Geant4 Simulation and Preliminary Characterization of the New Single Pixel

    NASA Astrophysics Data System (ADS)

    Macculi, C.; Argan, A.; D'Andrea, M.; Lotti, S.; Piro, L.; Biasotti, M.; Corsini, D.; Gatti, F.; Orlando, A.; Torrioli, G.

    2016-01-01

    The ATHENA observatory is the second large-class ESA mission, in the context of the Cosmic Vision 2015-2025, scheduled to be launched on 2028 at L2 orbit. One of the two planned focal plane instruments is the X-ray Integral Field Unit (X-IFU), which will be able to perform simultaneous high-grade energy spectroscopy and imaging over the 5 arcmin FoV by means of a kilo-pixel array of transition-edge sensor (TES) microcalorimeters, coupled to a high-quality X-ray optics. The X-IFU sensitivity is degraded by the particle background, induced by primary protons of both solar and cosmic rays' origin and secondary electrons. A Cryogenic AntiCoincidence (CryoAC) TES-based detector, located < 1 mm below the TES array, will allow the mission to reach the background level that enables its scientific goals. The CryoAC is a 4-pixel detector made of Silicon absorbers sensed by Iridium TESs. We currently achieve a TRL = 3-4 at the single-pixel level. We have designed and developed two further prototypes in order to reach TRL = 4. The design of the CryoAC has been also optimized using the Geant4 simulation tool. Here we will describe some results from the Geant4 simulations performed to optimize the design and preliminary test results from the first of the two detectors, 1 cm2 area, made of 65 Ir TESs.

  4. The Cryogenic AntiCoincidence Detector for the ATHENA X-IFU: Design Aspects by Geant4 Simulation and Preliminary Characterization of the New Single Pixel

    NASA Astrophysics Data System (ADS)

    Macculi, C.; Argan, A.; D'Andrea, M.; Lotti, S.; Piro, L.; Biasotti, M.; Corsini, D.; Gatti, F.; Orlando, A.; Torrioli, G.

    2016-08-01

    The ATHENA observatory is the second large-class ESA mission, in the context of the Cosmic Vision 2015-2025, scheduled to be launched on 2028 at L2 orbit. One of the two planned focal plane instruments is the X-ray Integral Field Unit (X-IFU), which will be able to perform simultaneous high-grade energy spectroscopy and imaging over the 5 arcmin FoV by means of a kilo-pixel array of transition-edge sensor (TES) microcalorimeters, coupled to a high-quality X-ray optics. The X-IFU sensitivity is degraded by the particle background, induced by primary protons of both solar and cosmic rays' origin and secondary electrons. A Cryogenic AntiCoincidence (CryoAC) TES-based detector, located <1 mm below the TES array, will allow the mission to reach the background level that enables its scientific goals. The CryoAC is a 4-pixel detector made of Silicon absorbers sensed by Iridium TESs. We currently achieve a TRL = 3-4 at the single-pixel level. We have designed and developed two further prototypes in order to reach TRL = 4. The design of the CryoAC has been also optimized using the Geant4 simulation tool. Here we will describe some results from the Geant4 simulations performed to optimize the design and preliminary test results from the first of the two detectors, 1 cm2 area, made of 65 Ir TESs.

  5. Geant4-DNA: overview and recent developments

    NASA Astrophysics Data System (ADS)

    Štěpán, Václav

    software already available for download, as well as future perspectives, will be presented, on behalf of the Geant4-DNA Collaboration.

  6. The Geant4 Bertini Cascade

    SciTech Connect

    Wright, D. H.; Kelsey, M. H.

    2015-12-01

    One of the medium energy hadron–nucleus interaction models in the Geant4 simulation toolkit is based partly on the Bertini intranuclear cascade model. Since its initial appearance in the toolkit, this model has been largely re-written in order to extend its physics capabilities and to reduce its memory footprint. Physics improvements include extensions in applicable energy range and incident particle types, and improved hadron–nucleon cross-sections and angular distributions. Interfaces have also been developed which allow the model to be coupled with other Geant4 models at lower and higher energies. The inevitable speed reductions due to enhanced physics have been mitigated by memory and CPU efficiency improvements. Details of these improvements, along with selected comparisons of the model to data, are discussed.

  7. The Geant4 Bertini Cascade

    NASA Astrophysics Data System (ADS)

    Wright, D. H.; Kelsey, M. H.

    2015-12-01

    One of the medium energy hadron-nucleus interaction models in the GEANT4 simulation toolkit is based partly on the Bertini intranuclear cascade model. Since its initial appearance in the toolkit, this model has been largely re-written in order to extend its physics capabilities and to reduce its memory footprint. Physics improvements include extensions in applicable energy range and incident particle types, and improved hadron-nucleon cross-sections and angular distributions. Interfaces have also been developed which allow the model to be coupled with other GEANT4 models at lower and higher energies. The inevitable speed reductions due to enhanced physics have been mitigated by memory and CPU efficiency improvements. Details of these improvements, along with selected comparisons of the model to data, are discussed.

  8. Introduction to the Geant4 Simulation toolkit

    NASA Astrophysics Data System (ADS)

    Guatelli, S.; Cutajar, D.; Oborn, B.; Rosenfeld, A. B.

    2011-05-01

    Geant4 is a Monte Carlo simulation Toolkit, describing the interactions of particles with matter. Geant4 is widely used in radiation physics research, from High Energy Physics, to medical physics and space science, thanks to its sophisticated physics component, coupled with advanced functionality in geometry description. Geant4 is widely used at the Centre for Medical Radiation Physics (CMRP), at the University of Wollongong, to characterise and optimise novel detector concepts, radiotherapy treatments, and imaging solutions. This lecture consists of an introduction to Monte Carlo method, and to Geant4. Particular attention will be devoted to the Geant4 physics component, and to the physics models describing electromagnetic and hadronic physics interactions. The second part of the lecture will be focused on the methodology to adopt to develop a Geant4 simulation application.

  9. Introduction to the Geant4 Simulation toolkit

    SciTech Connect

    Guatelli, S.; Cutajar, D.; Rosenfeld, A. B.; Oborn, B.

    2011-05-05

    Geant4 is a Monte Carlo simulation Toolkit, describing the interactions of particles with matter. Geant4 is widely used in radiation physics research, from High Energy Physics, to medical physics and space science, thanks to its sophisticated physics component, coupled with advanced functionality in geometry description. Geant4 is widely used at the Centre for Medical Radiation Physics (CMRP), at the University of Wollongong, to characterise and optimise novel detector concepts, radiotherapy treatments, and imaging solutions. This lecture consists of an introduction to Monte Carlo method, and to Geant4. Particular attention will be devoted to the Geant4 physics component, and to the physics models describing electromagnetic and hadronic physics interactions. The second part of the lecture will be focused on the methodology to adopt to develop a Geant4 simulation application.

  10. The Geant4 physics validation repository

    DOE PAGESBeta

    Wenzel, H.; Yarba, J.; Dotti, A.

    2015-01-01

    The Geant4 collaboration regularly performs validation and regression tests. The results are stored in a central repository and can be easily accessed via a web application. In this article we describe the Geant4 physics validation repository which consists of a relational database storing experimental data and Geant4 test results, a java API and a web application. Lastly, the functionality of these components and the technology choices we made are also described

  11. The Geant4 physics validation repository

    NASA Astrophysics Data System (ADS)

    Wenzel, H.; Yarba, J.; Dotti, A.

    2015-12-01

    The Geant4 collaboration regularly performs validation and regression tests. The results are stored in a central repository and can be easily accessed via a web application. In this article we describe the Geant4 physics validation repository which consists of a relational database storing experimental data and Geant4 test results, a java API and a web application. The functionality of these components and the technology choices we made are also described.

  12. The Geant4 Physics Validation Repository

    SciTech Connect

    Wenzel, H.; Yarba, J.; Dotti, A.

    2015-12-23

    The Geant4 collaboration regularly performs validation and regression tests. The results are stored in a central repository and can be easily accessed via a web application. In this article we describe the Geant4 physics validation repository which consists of a relational database storing experimental data and Geant4 test results, a java API and a web application. The functionality of these components and the technology choices we made are also described

  13. Visualization drivers for Geant4

    SciTech Connect

    Beretvas, Andy; /Fermilab

    2005-10-01

    This document is on Geant4 visualization tools (drivers), evaluating pros and cons of each option, including recommendations on which tools to support at Fermilab for different applications. Four visualization drivers are evaluated. They are OpenGL, HepRep, DAWN and VRML. They all have good features, OpenGL provides graphic output without an intermediate file. HepRep provides menus to assist the user. DAWN provides high quality plots and even for large files produces output quickly. VRML uses the smallest disk space for intermediate files. Large experiments at Fermilab will want to write their own display. They should proceed to make this display graphics independent. Medium experiment will probably want to use HepRep because of it's menu support. Smaller scale experiments will want to use OpenGL in the spirit of having immediate response, good quality output and keeping things simple.

  14. Implementing NRF Physics in Geant4

    SciTech Connect

    Jordan, David V.; Warren, Glen A.

    2006-07-01

    The Geant4 radiation transport Monte Carlo code toolkit currently does not support nuclear resonance fluorescence (NRF). After a brief review of NRF physics, plans for implementing this physics process in Geant4, and validating the output of the code, are described. The plans will be executed as Task 3 of project 50799, "Nuclear Resonance Fluorescence Signatures (NuRFS)".

  15. GEANT4 and Secondary Particle Production

    NASA Technical Reports Server (NTRS)

    Patterson, Jeff

    2004-01-01

    GEANT 4 is a Monte Carlo tool set developed by the High Energy Physics Community (CERN, SLAC, etc) to perform simulations of complex particle detectors. GEANT4 is the ideal tool to study radiation transport and should be applied to space environments and the complex geometries of modern day spacecraft.

  16. Alpha Coincidence Spectroscopy studied with GEANT4

    SciTech Connect

    Dion, Michael P.; Miller, Brian W.; Tatishvili, Gocha; Warren, Glen A.

    2013-11-02

    Abstract The high-energy side of peaks in alpha spectra, e.g. 241Am, as measured with a silicon detector has structure caused mainly by alpha-conversion electron and to some extent alphagamma coincidences. We compare GEANT4 simulation results to 241Am alpha spectroscopy measurements with a passivated implanted planar silicon detector. A large discrepancy between the measurements and simulations suggest that the GEANT4 photon evaporation database for 237Np (daughter of 241Am decay) does not accurately describe the conversion electron spectrum and therefore was found to have large discrepancies with experimental measurements. We describe how to improve the agreement between GEANT4 and alpha spectroscopy for actinides of interest by including experimental measurements of conversion electron spectroscopy into the photon evaporation database.

  17. Medical Applications of the Geant4 Toolkit

    NASA Astrophysics Data System (ADS)

    Agostinelli, S.; Chauvie, S.; Foppiano, F.; Garelli, S.; Marchetto, F.; Pia, M. G.; Nieminen, P.; Rolando, V.; Solano, A.

    A powerful and suitable tool for attacking the problem of the production and transport of different beams in biological matter is offered by the Geant4 Simulation Toolkit. Various activities in progress in the domain of medical applications are presented: studies on calibration of br achy therapie sources and termoluminescent dosimeters, studies of a complete 3-D inline dosimeter, development of general tools for CT interface for treatment planning, studies involving neutron transport, etc. A novel approach, based on the Geant4 Toolkit, for the study of radiation damage at the cellular and DNA level, is also presented.

  18. Comparison of GEANT4 very low energy cross section models with experimental data in water

    SciTech Connect

    Incerti, S.; Ivanchenko, A.; Karamitros, M.; Mantero, A.; Moretto, P.; Tran, H. N.; Mascialino, B.; Champion, C.; Ivanchenko, V. N.; Bernal, M. A.; Francis, Z.; Villagrasa, C.; Baldacchino, G.; Gueye, P.; Capra, R.; Nieminen, P.; Zacharatou, C.

    2010-09-15

    Purpose: The GEANT4 general-purpose Monte Carlo simulation toolkit is able to simulate physical interaction processes of electrons, hydrogen and helium atoms with charge states (H{sup 0}, H{sup +}) and (He{sup 0}, He{sup +}, He{sup 2+}), respectively, in liquid water, the main component of biological systems, down to the electron volt regime and the submicrometer scale, providing GEANT4 users with the so-called ''GEANT4-DNA'' physics models suitable for microdosimetry simulation applications. The corresponding software has been recently re-engineered in order to provide GEANT4 users with a coherent and unique approach to the simulation of electromagnetic interactions within the GEANT4 toolkit framework (since GEANT4 version 9.3 beta). This work presents a quantitative comparison of these physics models with a collection of experimental data in water collected from the literature. Methods: An evaluation of the closeness between the total and differential cross section models available in the GEANT4 toolkit for microdosimetry and experimental reference data is performed using a dedicated statistical toolkit that includes the Kolmogorov-Smirnov statistical test. The authors used experimental data acquired in water vapor as direct measurements in the liquid phase are not yet available in the literature. Comparisons with several recommendations are also presented. Results: The authors have assessed the compatibility of experimental data with GEANT4 microdosimetry models by means of quantitative methods. The results show that microdosimetric measurements in liquid water are necessary to assess quantitatively the validity of the software implementation for the liquid water phase. Nevertheless, a comparison with existing experimental data in water vapor provides a qualitative appreciation of the plausibility of the simulation models. The existing reference data themselves should undergo a critical interpretation and selection, as some of the series exhibit significant

  19. Design Software

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A NASA contractor and Small Business Innovation Research (SBIR) participant has converted its research into commercial software products for auto design, structural analysis and other applications. ViGYAN, Inc., utilizing the aeronautical research principle of computational fluid dynamics, has created - with VGRID3D and VPLOT3D - an easier alternative to conventional structured grids for fluid dynamic calculations.

  20. GEANT4 Simulation of the NPDGamma Experiment

    NASA Astrophysics Data System (ADS)

    Frlez, Emil

    2014-03-01

    The n-> + p --> d + γ experiment, currently taking data at the Oak Ridge SNS facility, is a high-precision measurement of weak nuclear forces at low energies. Detecting the correlation between the cold neutron spin and photon direction in the capture of neutrons on Liquid Hydrogen (LH) target, the experiment is sensitive to the properties of neutral weak current. We have written a GEANT4 Monte Carlo simulation of the NPDGamma detector that, in addition to the active CsI detectors, also includes different targets and passive materials as well as the beam line elements. The neutron beam energy spectrum, its profiles, divergencies, and time-of-flight are simulated in detail. We have used the code to cross-calibrate the positions of (i) polarized LH target, (ii) Aluminum target, and (iii) CCl4 target. The responses of the 48 CsI detectors in the simulation were fixed using data taken on the LH target. Both neutron absorption as well as scattering and thermal processes were turned on in the GEANT4 physics lists. We use the results to simulate in detail the data obtained with different targets used in the experiment within a comprehensive analysis. This work is supported by NSF grant PHY-1307328.

  1. Integration of g4tools in Geant4

    NASA Astrophysics Data System (ADS)

    Hřivnáčová, Ivana

    2014-06-01

    g4tools, that is originally part of the inlib and exlib packages, provides a very light and easy to install set of C++ classes that can be used to perform analysis in a Geant4 batch program. It allows to create and manipulate histograms and ntuples, and write them in supported file formats (ROOT, AIDA XML, CSV and HBOOK). It is integrated in Geant4 through analysis manager classes, thus providing a uniform interface to the g4tools objects and also hiding the differences between the classes for different supported output formats. Moreover, additional features, such as for example histogram activation or support for Geant4 units, are implemented in the analysis classes following users requests. A set of Geant4 user interface commands allows the user to create histograms and set their properties interactively or in Geant4 macros. g4tools was first introduced in the Geant4 9.5 release where its use was demonstrated in one basic example, and it is already used in a majority of the Geant4 examples within the Geant4 9.6 release. In this paper, we will give an overview and the present status of the integration of g4tools in Geant4 and report on upcoming new features.

  2. Geant4-Simulations for cellular dosimetry in nuclear medicine.

    PubMed

    Freudenberg, Robert; Wendisch, Maria; Kotzerke, Jörg

    2011-12-01

    The application of unsealed radionuclides in radiobiological experiments can lead to intracellular radionuclide uptake and an increased absorbed dose. Accurate dose quantification is essential to assess observed radiobiological effects. Due to small cellular dimensions direct dose measurement is impossible. We will demonstrate the application of Monte Carlo simulations for dose calculation. Dose calculations were performed using the Geant4 Monte Carlo toolkit, wherefore typical experimental situations were designed. Dose distributions inside wells were simulated for different radionuclides. S values were simulated for spherical cells and cell monolayers of different diameter. Concomitantly experiments were performed using the PC Cl3 cell line with mediated radionuclide uptake. For various activity distributions cellular survival was measured. We yielded S values for dose distribution inside the wells. Calculated S values for a single cell are in good agreement to S values provided in the literature (ratio 0.87 to 1.07). Cross-dose is up to ten times higher for Y-90. Concomitantly performed cellular experiments confirm the dose calculation. Furthermore the necessity of correct dose calculation was shown for assessment of radiobiological effects after application of unsealed radionuclides. Thereby the feasibility of using Geant4 was demonstrated. PMID:21983023

  3. Application of GEANT4 in the Development of New Radiation Therapy Treatment Methods

    NASA Astrophysics Data System (ADS)

    Brahme, Anders; Gudowska, Irena; Larsson, Susanne; Andreassen, Björn; Holmberg, Rickard; Svensson, Roger; Ivanchenko, Vladimir; Bagulya, Alexander; Grichine, Vladimir; Starkov, Nikolay

    2006-04-01

    There is a very fast development of new radiation treatment methods today, from advanced use of intensity modulated photon and electron beams to light ion therapy with narrow scanned beam based treatment units. Accurate radiation transport calculations are a key requisite for these developments where Geant4 is a very useful Monte Carlo code for accurate design of new treatment units. Today we cannot only image the tumor by PET-CT imaging before the treatment but also determine the tumor sensitivity to radiation and even measure in vivo the delivered absorbed dose in three dimensions in the patient. With such methods accurate Monte Carlo calculations will make radiation therapy an almost exact science where the curative doses can be calculated based on patient individual response data. In the present study results from the application of Geant4 are discussed and the comparisons between Geant4 and experimental and other Monte Carlo data are presented.

  4. Medical Applications of the Geant4 Simulation Toolkit

    NASA Astrophysics Data System (ADS)

    Perl, Joseph

    2008-03-01

    Geant4 is a toolkit for the simulation of the passage of particles through matter. While Geant4 was originally developed for High Energy Physics (HEP), applications now include Nuclear, Space and Medical Physics. Medical applications of Geant4 in North America and throughout the world have been increasing rapidly due to the overall growth of Monte Carlo use in Medical Physics and the unique qualities of Geant4 as an all-particle code able to handle complex geometry, motion and fields with the flexibility of modern programming and an open and free source code. Work has included characterizing beams and brachytherapy sources, treatment planning, retrospective studies, imaging and validation. This talk will provide an overview of these applications, with a focus on therapy, and will discuss how Geant4 has responded to the specific challenges of moving from HEP to Medical applications.

  5. Experimental spectra analysis in THM with the help of simulation based on the Geant4 framework

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Bo; Wen, Qun-Gang; Zhou, Shu-Hua; Jiang, Zong-Jun; Fu, Yuan-Yong; Zhou, Jing; Meng, Qiu-Ying; Wang, Xiao-Lian

    2015-05-01

    The Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles at astrophysical energies. The Trojan-horse method (THM) has been introduced to solve the difficulties as a powerful indirect tool. In order to understand experimental spectra better, Geant4 is employed to simulate the method. Validity and reliability of simulation data are examined by comparing the experimental data with simulated results. The Geant4 simulation of THM improves data analysis and is beneficial to the design for future related experiments. Supported by National Natural Science Foundation of China (11075218, 10575132) and Beijing Natural Science Foundation (1122017)

  6. An Overview of the Geant4 Toolkit

    SciTech Connect

    Apostolakis, John; Wright, Dennis H.

    2007-03-19

    Geant4 is a toolkit for the simulation of the transport of radiation through matter. With a flexible kernel and choices between different physics modeling choices, it has been tailored to the requirements of a wide range of applications.With the toolkit a user can describe a setup's or detector's geometry and materials, navigate inside it, simulate the physical interactions using a choice of physics engines, underlying physics cross-sections and models, visualise and store results.Physics models describing electromagnetic and hadronic interactions are provided, as are decays and processes for optical photons. Several models, with different precision and performance are available for many processes. The toolkit includes coherent physics model configurations, which are called physics lists. Users can choose an existing physics list or create their own, depending on their requirements and the application area. A clear structure and readable code, enable the user to investigate the origin of physics results.Application areas include detector simulation and background simulation in High Energy Physics experiments, simulation of accelerator setups, studies in medical imaging and treatment, and the study of the effects of solar radiation on spacecraft instruments.

  7. An Overview of the GEANT4 Toolkit

    SciTech Connect

    Apostolakis, John; Wright, Dennis H.; /SLAC

    2007-10-05

    Geant4 is a toolkit for the simulation of the transport of radiation through matter. With a flexible kernel and choices between different physics modeling choices, it has been tailored to the requirements of a wide range of applications. With the toolkit a user can describe a setup's or detector's geometry and materials, navigate inside it, simulate the physical interactions using a choice of physics engines, underlying physics cross-sections and models, visualize and store results. Physics models describing electromagnetic and hadronic interactions are provided, as are decays and processes for optical photons. Several models, with different precision and performance are available for many processes. The toolkit includes coherent physics model configurations, which are called physics lists. Users can choose an existing physics list or create their own, depending on their requirements and the application area. A clear structure and readable code, enable the user to investigate the origin of physics results. Application areas include detector simulation and background simulation in High Energy Physics experiments, simulation of accelerator setups, studies in medical imaging and treatment, and the study of the effects of solar radiation on spacecraft instruments.

  8. Simulation study of Fast Neutron Radiography using GEANT4

    NASA Astrophysics Data System (ADS)

    Bishnoi, S.; Thomas, R. G.; Sarkar, P. S.; Datar, V. M.; Sinha, A.

    2015-02-01

    Fast neutron radiography (FNR) is an important non-destructive technique for the imaging of thick bulk material. We are designing a FNR system using a laboratory based 14 MeV D-T neutron generator [1]. Simulation studies have been carried using Monte Carlo based GEANT4 code to understand the response of the FNR system for various objects. Different samples ranging from low Z, metallic and high Z materials were simulated for their radiographic images. The quality of constructed neutron radiography images in terms of relative contrast ratio and the contrast to noise ratio were investigated for their dependence on various parameters such as thickness, voids inside high/low Z material and also for low Z material hidden behind high Z material. We report here the potential and limitations of FNR for imaging different materials and a few configurations and also the possible areas where FNR can be implemented.

  9. Beam simulation tools for GEANT4 (and neutrino source applications)

    SciTech Connect

    V.Daniel Elvira, Paul Lebrun and Panagiotis Spentzouris

    2002-12-03

    Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the High Energy Physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. Although there are many computer programs for beam physics simulations, Geant4 is ideal to model a beam going through material or a system with a beam line integrated to a complex detector. There are many examples in the current international High Energy Physics programs, such as studies related to a future Neutrino Factory, a Linear Collider, and a very Large Hadron Collider.

  10. Simulation of Cold Neutron Experiments using GEANT4

    NASA Astrophysics Data System (ADS)

    Frlez, Emil; Hall, Joshua; Root, Melinda; Baessler, Stefan; Pocanic, Dinko

    2013-10-01

    We review the available GEANT4 physics processes for the cold neutrons in the energy range 1-100 meV. We consider the cases of the neutron beam interacting with (i) para- and ortho- polarized liquid hydrogen, (ii) Aluminum, and (iii) carbon tetrachloride (CCl4) targets. Scattering, thermal and absorption cross sections used by GEANT4 and MCNP6 libraries are compared with the National Nuclear Data Center (NNDC) compilation. NPDGamma detector simulation is presented as an example of the implementation of the resulting GEANT4 code. This work is supported by NSF grant PHY-0970013.

  11. SU-E-J-72: Geant4 Simulations of Spot-Scanned Proton Beam Treatment Plans

    SciTech Connect

    Kanehira, T; Sutherland, K; Matsuura, T; Umegaki, K; Shirato, H

    2014-06-01

    Purpose: To evaluate density inhomogeneities which can effect dose distributions for real-time image gated spot-scanning proton therapy (RGPT), a dose calculation system, using treatment planning system VQA (Hitachi Ltd., Tokyo) spot position data, was developed based on Geant4. Methods: A Geant4 application was developed to simulate spot-scanned proton beams at Hokkaido University Hospital. A CT scan (0.98 × 0.98 × 1.25 mm) was performed for prostate cancer treatment with three or four inserted gold markers (diameter 1.5 mm, volume 1.77 mm3) in or near the target tumor. The CT data was read into VQA. A spot scanning plan was generated and exported to text files, specifying the beam energy and position of each spot. The text files were converted and read into our Geant4-based software. The spot position was converted into steering magnet field strength (in Tesla) for our beam nozzle. Individual protons were tracked from the vacuum chamber, through the helium chamber, steering magnets, dose monitors, etc., in a straight, horizontal line. The patient CT data was converted into materials with variable density and placed in a parametrized volume at the isocenter. Gold fiducial markers were represented in the CT data by two adjacent voxels (volume 2.38 mm3). 600,000 proton histories were tracked for each target spot. As one beam contained about 1,000 spots, approximately 600 million histories were recorded for each beam on a blade server. Two plans were considered: two beam horizontal opposed (90 and 270 degree) and three beam (0, 90 and 270 degree). Results: We are able to convert spot scanning plans from VQA and simulate them with our Geant4-based code. Our system can be used to evaluate the effect of dose reduction caused by gold markers used for RGPT. Conclusion: Our Geant4 application is able to calculate dose distributions for spot scanned proton therapy.

  12. Polycrystalline neutron scattering for Geant4: NXSG4

    NASA Astrophysics Data System (ADS)

    Kittelmann, T.; Boin, M.

    2015-04-01

    An extension to Geant4 based on the nxs library is presented. It has been implemented in order to include effects of low-energy neutron scattering in polycrystalline materials, and is made available to the scientific community.

  13. Geant4 electromagnetic physics updates for space radiation effects simulation

    NASA Astrophysics Data System (ADS)

    Ivantchenko, Anton; Nieminen, Petteri; Incerti, Sebastien; Santin, Giovanni; Ivantchenko, Vladimir; Grichine, Vladimir; Allison, John; Karamitos, Mathiew

    The Geant4 toolkit is used in many applications including space science studies. The new Geant4 version 10.0 released in December 2013 includes a major revision of the toolkit and offers multi-threaded mode for event level parallelism. At the same time, Geant4 electromagnetic and hadronic physics sub-libraries have been significantly updated. In order to validate the new and updated models Geant4 verification tests and benchmarks were extended. Part of these developments was sponsored by the European Space Agency in the context of research aimed at modelling radiation biological end effects. In this work, we present an overview of results of several benchmarks for electromagnetic physics models relevant to space science. For electromagnetic physics, recently Compton scattering, photoelectric effect, and Rayleigh scattering models have been improved and extended down to lower energies. Models of ionization and fluctuations have also been improved; special micro-dosimetry models for Silicon and liquid water were introduced; the main multiple scattering model was consolidated; and the atomic de-excitation module has been made available to all models. As a result, Geant4 predictions for space radiation effects obtained with different Physics Lists are in better agreement with the benchmark data than previous Geant4 versions. Here we present results of electromagnetic tests and models comparison in the energy interval 10 eV - 10 MeV.

  14. artG4: A Generic Framework for Geant4 Simulations

    SciTech Connect

    Arvanitis, Tasha; Lyon, Adam

    2014-01-01

    A small experiment must devote its limited computing expertise to writing physics code directly applicable to the experiment. A software 'framework' is essential for providing an infrastructure that makes writing the physics-relevant code easy. In this paper, we describe a highly modular and easy to use framework for writing Geant4 based simulations called 'artg4'. This framework is a layer on top of the art framework.

  15. Characterisation of a SAGe well detector using GEANT4 and LabSOCS

    NASA Astrophysics Data System (ADS)

    Britton, R.; Davies, A. V.

    2015-06-01

    This paper reports on the performance of a recently developed Small Anode Germanium (SAGe) well detector from Canberra Industries. This has been specifically designed to improve the energy resolution of the detector, such that it is comparable to the performance of broad-energy designs while achieving far higher efficiencies. Accurate efficiency characterisations and cascade summing correction factors are crucial for quantifying the radionuclides present in environmental samples, and these were calculated for the complex geometry posed by the well detector using two different methodologies. The first relied on Monte-Carlo simulations based upon the GEANT4 toolkit, and the second utilised Canberra Industries GENIE™ 2000 Gamma Analysis software in conjunction with a LabSOCS™ characterisation. Both were found to be in excellent agreement for all nuclides except for 152Eu, which presents a known issue in the Canberra software (all nuclides affected by this issue were well documented, and fixes are being developed). The correction factors were used to analyse two fully characterised reference samples, yielding results in good agreement with the accepted activity concentrations. Given the sensitivity of well type geometries to cascade summing, this represents a considerable achievement, and paves the way for the use of the SAGe well detector in analysis of 'real-world' environmental samples. With the efficiency increase when using the SAGe well in place of a BEGe, substantial reductions in the Minimum Detectable Activity (MDA) should be achievable for a range of nuclides.

  16. GEANT4 Simulation of Neutron Detector for DAMPE

    NASA Astrophysics Data System (ADS)

    He, M.; Ma, T.; Chang, J.; Zhang, Y.; Huang, Y. Y.; Zang, J. J.; Wu, J.; Dong, T. K.

    2016-01-01

    During recent tens of years dark matter has gradually become a hot topic in astronomical research field, and related theory researches and experiment projects change with each passing day. The Dark Matter Particle Explorer (DAMPE) of our country is proposed under this background. As the probing object involves high energy electrons, appropriate methods must be taken to distinguish them from protons in order to reduce the event probability of other charged particles (e.g. a proton) being mistaken as electrons. The experiments show that, the hadronic shower of high energy proton in BGO electromagnetic calorimeter, which is usually accompanied by the emitting of large number of secondary neutrons, is significantly different from the electromagnetic shower of high energy electron. Through the detection of secondary neutron signal emitting from the bottom of BGO electromagnetic calorimeter and the shower shape of incident particles in BGO electromagnetic calorimeter, we can effectively distinguish whether the incident particles are high energy protons or electrons. This paper introduces the structure and detecting principle of DAMPE neutron detector. We use Monte-Carlo method with GEANT4 software to simulate the signal emitting from protons and electrons at characteristic energy in the neutron detector, and finally summarize the neutron detector's ability to distinguish protons and electrons under different electron acception efficiencies.

  17. Monte Carlo simulation of a photodisintegration of 3 H experiment in Geant4

    NASA Astrophysics Data System (ADS)

    Gray, Isaiah

    2013-10-01

    An upcoming experiment involving photodisintegration of 3 H at the High Intensity Gamma-Ray Source facility at Duke University has been simulated in the software package Geant4. CAD models of silicon detectors and wire chambers were imported from Autodesk Inventor using the program FastRad and the Geant4 GDML importer. Sensitive detectors were associated with the appropriate logical volumes in the exported GDML file so that changes in detector geometry will be easily manifested in the simulation. Probability distribution functions for the energy and direction of outgoing protons were generated using numerical tables from previous theory, and energies and directions were sampled from these distributions using a rejection sampling algorithm. The simulation will be a useful tool to optimize detector geometry, estimate background rates, and test data analysis algorithms. This work was supported by the Triangle Universities Nuclear Laboratory REU program at Duke University.

  18. Progress in Geant4 Electromagnetic Physics Modelling and Validation

    NASA Astrophysics Data System (ADS)

    Apostolakis, J.; Asai, M.; Bagulya, A.; Brown, J. M. C.; Burkhardt, H.; Chikuma, N.; Cortes-Giraldo, M. A.; Elles, S.; Grichine, V.; Guatelli, S.; Incerti, S.; Ivanchenko, V. N.; Jacquemier, J.; Kadri, O.; Maire, M.; Pandola, L.; Sawkey, D.; Toshito, T.; Urban, L.; Yamashita, T.

    2015-12-01

    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.

  19. Geant4 validation with CMS calorimeters test-beam data

    SciTech Connect

    Piperov, Stefan; /Sofiya, Inst. Nucl. Res. /Fermilab

    2008-08-01

    CMS experiment is using Geant4 for Monte-Carlo simulation of the detector setup. Validation of physics processes describing hadronic showers is a major concern in view of getting a proper description of jets and missing energy for signal and background events. This is done by carrying out an extensive studies with test beam using the prototypes or real detector modules of the CMS calorimeter. These data are matched with Geant4 predictions. Tuning of the Geant4 models is carried out and steps to be used in reproducing detector signals are defined in view of measurements of energy response, energy resolution, transverse and longitudinal shower profiles for a variety of hadron beams over a broad energy spectrum between 2 to 300 GeV/c.

  20. GEANT4 simulation of APEX background radiation and shielding

    NASA Astrophysics Data System (ADS)

    Kaluarachchi, Maduka M.; Cates, Gordon D.; Wojtsekhowski, B.

    2015-04-01

    The A' Experiment (APEX), which is approved to run at the Thomas Jefferson National Accelerator Facility (JLab) Hall A, will search for a new vector boson that is hypothesized to be a possible force carrier that couples to dark matter. APEX results should be sensitive to the mass range of 65 MeV to 550 MeV, and high sensitivity will be achieved by means of a high intensity 100 μA beam on a 0.5 g/cm2 Tungsten target resulting in very high luminosity. The experiment should be able to observe the A ' with a coupling constant α ' ~ 1 × 107 times smaller than the electromagnetic coupling constant α. To deal safely with such enormous intensity and luminosity, a full radiation analysis must be used to help with the design of proper radiation shielding. The purpose of this talk is to present preliminary results obtained by simulating radiation background from the APEX experiment using the 3D Monte-Carlo transport code Geant4. Included in the simulation is a detailed Hall A setup: the hall, spectrometers and shield house, beam dump, beam line, septa magnet with its field, as well as the production target. The results were compared to the APEX test run data and used in development of the radiation shielding for sensitive electronics.

  1. New Geant4 based simulation tools for space radiation shielding and effects analysis

    NASA Astrophysics Data System (ADS)

    Santina, G.; Nieminen, P.; Evansa, H.; Daly, E.; Lei, F.; Truscott, P. R.; Dyer, C. S.; Quaghebeur, B.; Heynderickx, D.

    2003-09-01

    We present here a set of tools for space applications based on the Geant4 simulation toolkit, developed for radiation shielding analysis as part of the European Space Agency (ESA) activities in the Geant4 collaboration. The Sector Shielding Analysis Tool (SSAT) and the Materials and Geometry Association (MGA) utility will first be described. An overview of the main features of the MUlti-LAyered Shielding SImulation Software tool (MULASSIS) will follow. The tool is specifically addressed to shielding optimization and effects analysis. A Java interface allows the use of MULASSIS by the space community over the World Wide Web, integrated in the widely used SPENVIS package. The analysis of the particle transport output provides automatically radiation fluence, ionising and NIEL dose and effects analysis. ESA is currently funding the porting of this tools to a lowcost parallel processor facility using the GRID technology under the ESA SpaceGRID initiative. Other Geant4 present and future projects will be presented related to the study of space environment effects on spacecrafts.

  2. Preliminary Investigation of Microdosimetric Track Structure Physics Models in Geant4-DNA and RITRACKS

    PubMed Central

    Bezak, Eva

    2015-01-01

    The major differences between the physics models in Geant4-DNA and RITRACKS Monte Carlo packages are investigated. Proton and electron ionisation interactions and electron excitation interactions in water are investigated in the current work. While these packages use similar semiempirical physics models for inelastic cross-sections, the implementation of these models is demonstrated to be significantly different. This is demonstrated in a simple Monte Carlo simulation designed to identify differences in interaction cross-sections. PMID:26124856

  3. Design software for reuse

    NASA Technical Reports Server (NTRS)

    Tracz, Will

    1990-01-01

    Viewgraphs are presented on the designing of software for reuse. Topics include terminology, software reuse maxims, the science of programming, an interface design example, a modularization example, and reuse and implementation guidelines.

  4. Beam Simulation Tools for GEANT4 (BT-V1.0). User's Guide

    SciTech Connect

    Elvira, V. Daniel; Lebrum, P.; Spentzouris, P.

    2002-12-02

    Geant4 is a tool kit developed by a collaboration of physicists and computer professionals in the high energy physics field for simulation of the passage of particles through matter. The motivation for the development of the Beam Tools is to extend the Geant4 applications to accelerator physics. The Beam Tools are a set of C++ classes designed to facilitate the simulation of accelerator elements: r.f. cavities, magnets, absorbers, etc. These elements are constructed from Geant4 solid volumes like boxes, tubes, trapezoids, or spheers. There are many computer programs for beam physics simulations, but Geant4 is ideal to model a beam through a material or to integrate a beam line with a complex detector. There are many such examples in the current international High Energy Physics programs. For instance, an essential part of the R&D associated with the Neutrino Source/Muon Collider accelerator is the ionization cooling channel, which is a section of the system aimed to reduce the size of the muon beam in phase space. The ionization cooling technique uses a combination of linacs and light absorbers to reduce the transverse momentum and size of the beam, while keeping the longitudinal momentum constant. The MuCool/MICE (muon cooling) experiments need accurate simulations of the beam transport through the cooling channel in addition to a detailed simulation of the detectors designed to measure the size of the beam. The accuracy of the models for physics processes associated with muon ionization and multiple scattering is critical in this type of applications. Another example is the simulation of the interaction region in future accelerators. The high luminosity and background environments expected in the Next Linear Collider (NLC) and the Very Large Hadron Collider (VLHC) pose great demand on the detectors, which may be optimized by means of a simulation of the detector-accelerator interface.

  5. The GEANT4 toolkit for microdosimetry calculations: application to microbeam radiation therapy (MRT).

    PubMed

    Spiga, J; Siegbahn, E A; Bräuer-Krisch, E; Randaccio, P; Bravin, A

    2007-11-01

    Theoretical dose distributions for microbeam radiation therapy (MRT) are computed in this paper using the GEANT4 Monte Carlo (MC) simulation toolkit. MRT is an innovative experimental radiotherapy technique carried out using an array of parallel microbeams of synchrotron-wiggler-generated x rays. Although the biological mechanisms underlying the effects of microbeams are still largely unknown, the effectiveness of MRT can be traced back to the natural ability of normal tissues to rapidly repair small damages to the vasculature, and on the lack of a similar healing process in tumoral tissues. Contrary to conventional therapy, in which each beam is at least several millimeters wide, the narrowness of the microbeams allows a rapid regeneration of the blood vessels along the beams' trajectories. For this reason the calculation of the "valley" dose is of crucial importance and the correct use of MC codes for such purposes must be understood. GEANT4 offers, in addition to the standard libraries, a specialized package specifically designed to deal with electromagnetic interactions of particles with matter for energies down to 250 eV. This package implements two different approaches for electron and photon transport, one based on evaluated data libraries, the other adopting analytical models. These features are exploited to cross-check theoretical computations for MRT. The lateral and depth dose profiles are studied for the irradiation of a 20 cm diameter, 20 cm long cylindrical phantom, with cylindrical sources of different size and energy. Microbeam arrays are simulated with the aid of superposition algorithms, and the ratios of peak-to-valley doses are computed for typical cases used in preclinical assays. Dose profiles obtained using the GEANT4 evaluated data libraries and analytical models are compared with simulation results previously obtained using the PENELOPE code. The results show that dose profiles computed with GEANT4's analytical model are almost

  6. The GEANT4 toolkit for microdosimetry calculations: Application to microbeam radiation therapy (MRT)

    SciTech Connect

    Spiga, J.; Siegbahn, E. A.; Braeuer-Krisch, E.; Randaccio, P.; Bravin, A.

    2007-11-15

    Theoretical dose distributions for microbeam radiation therapy (MRT) are computed in this paper using the GEANT4 Monte Carlo (MC) simulation toolkit. MRT is an innovative experimental radiotherapy technique carried out using an array of parallel microbeams of synchrotron-wiggler-generated x rays. Although the biological mechanisms underlying the effects of microbeams are still largely unknown, the effectiveness of MRT can be traced back to the natural ability of normal tissues to rapidly repair small damages to the vasculature, and on the lack of a similar healing process in tumoral tissues. Contrary to conventional therapy, in which each beam is at least several millimeters wide, the narrowness of the microbeams allows a rapid regeneration of the blood vessels along the beams' trajectories. For this reason the calculation of the 'valley' dose is of crucial importance and the correct use of MC codes for such purposes must be understood. GEANT4 offers, in addition to the standard libraries, a specialized package specifically designed to deal with electromagnetic interactions of particles with matter for energies down to 250 eV. This package implements two different approaches for electron and photon transport, one based on evaluated data libraries, the other adopting analytical models. These features are exploited to cross-check theoretical computations for MRT. The lateral and depth dose profiles are studied for the irradiation of a 20 cm diameter, 20 cm long cylindrical phantom, with cylindrical sources of different size and energy. Microbeam arrays are simulated with the aid of superposition algorithms, and the ratios of peak-to-valley doses are computed for typical cases used in preclinical assays. Dose profiles obtained using the GEANT4 evaluated data libraries and analytical models are compared with simulation results previously obtained using the PENELOPE code. The results show that dose profiles computed with GEANT4's analytical model are almost

  7. Adaptation of GEANT4 to Monte Carlo dose calculations based on CT data.

    PubMed

    Jiang, H; Paganetti, H

    2004-10-01

    The GEANT4 Monte Carlo code provides many powerful functions for conducting particle transport simulations with great reliability and flexibility. However, as a general purpose Monte Carlo code, not all the functions were specifically designed and fully optimized for applications in radiation therapy. One of the primary issues is the computational efficiency, which is especially critical when patient CT data have to be imported into the simulation model. In this paper we summarize the relevant aspects of the GEANT4 tracking and geometry algorithms and introduce our work on using the code to conduct dose calculations based on CT data. The emphasis is focused on modifications of the GEANT4 source code to meet the requirements for fast dose calculations. The major features include a quick voxel search algorithm, fast volume optimization, and the dynamic assignment of material density. These features are ready to be used for tracking the primary types of particles employed in radiation therapy such as photons, electrons, and heavy charged particles. Recalculation of a proton therapy treatment plan generated by a commercial treatment planning program for a paranasal sinus case is presented as an example. PMID:15543788

  8. Simulation and modeling for the stand-off radiation detection system (SORDS) using GEANT4

    SciTech Connect

    Hoover, Andrew S; Wallace, Mark; Galassi, Mark; Mocko, Michal; Palmer, David; Schultz, Larry; Tornga, Shawn

    2009-01-01

    A Stand-Off Radiation Detection System (SORDS) is being developed through a joint effort by Raytheon, Los Alamos National Laboratory, Bubble Technology Industries, Radiation Monitoring Devices, and the Massachusetts Institute of Technology, for the Domestic Nuclear Detection Office (DNDO). The system is a mobile truck-based platform performing detection, imaging, and spectroscopic identification of gamma-ray sources. A Tri-Modal Imaging (TMI) approach combines active-mask coded aperture imaging, Compton imaging, and shadow imaging techniques. Monte Carlo simulation and modeling using the GEANT4 toolkit was used to generate realistic data for the development of imaging algorithms and associated software code.

  9. GEANT4 simulations of Cherenkov reaction history diagnostics.

    PubMed

    Rubery, M S; Horsfield, C J; Herrmann, H W; Kim, Y; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedilleo, T J; McEvoy, A; Miller, E K; Stoeffl, W; Ali, Z; Toebbe, J

    2010-10-01

    This paper compares the results from a GEANT4 simulation of the gas Cherenkov detector 1 (GCD1) with previous simulations and experimental data from the Omega laser facility. The GCD1 collects gammas emitted during a deuterium-tritium capsule implosion and converts them, through several processes, to Cherenkov light. Photon signals are recorded using subnanosecond photomultiplier tubes, producing burn reaction histories. The GEANT4 GCD1 simulation is first benchmarked against ACCEPT, an integrated tiger series code, with good agreement. The simulation is subsequently compared with data from the Omega laser facility, where experiments have been performed to measure the effects of Hohlraum materials on reaction history signals, in preparation for experiments at the National Ignition Facility. PMID:21033850

  10. Accurate simulations of TEPC neutron spectra using Geant4

    NASA Astrophysics Data System (ADS)

    Taylor, G. C.; Hawkes, N. P.; Shippen, A.

    2015-11-01

    A Geant4 model of a tissue-equivalent proportional counter (TEPC) has been developed in which the calculated output spectrum exhibits unparalleled agreement with experiment for monoenergetic neutron fields at several energies below 20 MeV. The model uses the standard release of the Geant4 9.6 p2 code, but with a non-standard neutron cross section file as provided by Mendoza et al., and with the environment variable options recommended by the same authors. This configuration was found to produce significant improvements in the alpha-dominated region of the calculated response. In this paper, these improvements are presented, and the post-processing required to convert deposited energy into the number of ion pairs (which is the quantity actually measured experimentally) is discussed.

  11. GEANT4 simulations of Cherenkov reaction history diagnostics

    SciTech Connect

    Rubery, M. S.; Horsfield, C. J.; Herrmann, H. W.; Kim, Y.; Mack, J. M.; Young, C. S.; Caldwell, S. E.; Evans, S. C.; Sedilleo, T. J.; McEvoy, A.; Miller, E. K.; Stoeffl, W.; Ali, Z.

    2010-10-15

    This paper compares the results from a GEANT4 simulation of the gas Cherenkov detector 1 (GCD1) with previous simulations and experimental data from the Omega laser facility. The GCD1 collects gammas emitted during a deuterium-tritium capsule implosion and converts them, through several processes, to Cherenkov light. Photon signals are recorded using subnanosecond photomultiplier tubes, producing burn reaction histories. The GEANT4 GCD1 simulation is first benchmarked against ACCEPT, an integrated tiger series code, with good agreement. The simulation is subsequently compared with data from the Omega laser facility, where experiments have been performed to measure the effects of Hohlraum materials on reaction history signals, in preparation for experiments at the National Ignition Facility.

  12. Transmission Efficiency of the Sage Spectrometer Using GEANT4

    NASA Astrophysics Data System (ADS)

    Cox, D. M.; Herzberg, R.-D.; Papadakis, P.; Ali, F.; Butler, P. A.; Cresswell, J. R.; Mistry, A.; Sampson, J.; Seddon, D. A.; Thornhill, J.; Wells, D.; Konki, J.; Greenlees, P. T.; Rahkila, P.; Pakarinen, J.; Sandzelius, M.; Sorri, J.; Julin, R.; Coleman-Smith, P. J.; Lazarus, I. H.; Letts, S. C.; Simpson, J.; Pucknell, V. F. E.

    2014-09-01

    The new SAGE spectrometer allows simultaneous electron and γ-ray in-beam studies of heavy nuclei. A comprehensive GEANT4 simulation suite has been created for the SAGE spectrometer. This includes both the silicon detectors for electron detection and the germanium detectors for γ-ray detection. The simulation can be used for a wide variety of tests with the aim of better understanding the behaviour of SAGE. A number of aspects of electron transmission are presented here.

  13. Software Design Analyzer System

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.

    1985-01-01

    CRISP80 software design analyzer system a set of programs that supports top-down, hierarchic, modular structured design, and programing methodologies. CRISP80 allows for expression of design as picture of program.

  14. Electro and gamma nuclear physics in Geant4

    SciTech Connect

    J.P. Wellisch; M. Kossov; P. Degtyarenko

    2003-03-01

    Adequate description of electro and gamma nuclear physics is of utmost importance in studies of electron beam-dumps and intense electron beam accelerators. I also is mandatory to describe neutron backgrounds and activation in linear colliders. This physics was elaborated in Geant4 over the last year, and now entered into the stage of practical application. In the Geant4 Photo-nuclear data base there are at present about 50 nuclei for which the Photo-nuclear absorption cross sections have been measured. Of these, data on 14 nuclei are used to parametrize the gamma nuclear reaction cross-section The resulting cross section is a complex, factorized function of A and e = log(E{gamma}), where E{gamma} is the energy of the incident photon. Electro-nuclear reactions are so closely connected with Photo-nuclear reactions that sometimes they are often called ''Photo-nuclear''. The one-photon exchange mechanism dominates in Electro-nuclear reactions, and the electron can be substituted by a flux of photons. Folding this flux with the gamma-nuclear cross-section, we arrive at an acceptable description of the electro-nuclear physics. Final states in gamma and electro nuclear physics are described using chiral invariant phase-space decay at low gamma or equivalent photon energies, and quark gluon string model at high energies. We will present the modeling of this physics in Geant4, and show results from practical applications.

  15. GEANT4 Tuning For pCT Development

    NASA Astrophysics Data System (ADS)

    Yevseyeva, Olga; de Assis, Joaquim T.; Evseev, Ivan; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, João A. P.; Díaz, Katherin S.; Hormaza, Joel M.; Lopes, Ricardo T.

    2011-08-01

    Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development.

  16. Measuring software design

    NASA Technical Reports Server (NTRS)

    1986-01-01

    An extensive series of studies of software design measures conducted by the Software Engineering Laboratory is described. Included are the objectives and results of the studies, the method used to perform the studies, and the problems encountered. The document should be useful to researchers planning similar studies as well as to managers and designers concerned with applying quantitative design measures.

  17. Calculation of HPGe efficiency for environmental samples: comparison of EFFTRAN and GEANT4

    NASA Astrophysics Data System (ADS)

    Nikolic, Jelena; Vidmar, Tim; Jokovic, Dejan; Rajacic, Milica; Todorovic, Dragana

    2014-11-01

    Determination of full energy peak efficiency is one of the most important tasks that have to be performed before gamma spectrometry of environmental samples. Many methods, including measurement of specific reference materials, Monte Carlo simulations, efficiency transfer and semi empirical calculations, were developed in order to complete this task. Monte Carlo simulation, based on GEANT4 simulation package and EFFTRAN efficiency transfer software are applied for the efficiency calibration of three detectors, readily used in the Environment and Radiation Protection Laboratory of Institute for Nuclear Sciences Vinca, for measurement of environmental samples. Efficiencies were calculated for water, soil and aerosol samples. The aim of this paper is to perform efficiency calculations for HPGe detectors using both GEANT4 simulation and EFFTRAN efficiency transfer software and to compare obtained results with the experimental results. This comparison should show how the two methods agree with experimentally obtained efficiencies of our measurement system and in which part of the spectrum do the discrepancies appear. The detailed knowledge of accuracy and precision of both methods should enable us to choose an appropriate method for each situation that is presented in our and other laboratories on a daily basis.

  18. GEANT4 for breast dosimetry: parameters optimization study

    NASA Astrophysics Data System (ADS)

    Fedon, C.; Longo, F.; Mettivier, G.; Longo, R.

    2015-08-01

    Mean glandular dose (MGD) is the main dosimetric quantity in mammography. MGD evaluation is obtained by multiplying the entrance skin air kerma (ESAK) by normalized glandular dose (DgN) coefficients. While ESAK is an empirical quantity, DgN coefficients can only be estimated with Monte Carlo (MC) methods. Thus, a MC parameters benchmark is needed for effectively evaluating DgN coefficients. GEANT4 is a MC toolkit suitable for medical purposes that offers to the users several computational choices. In this work we investigate the GEANT4 performances testing the main PhysicsLists for medical applications. Four electromagnetic PhysicsLists were implemented: the linear attenuation coefficients were calculated for breast glandularity 0%, 50%, 100% in the energetic range 8-50 keV and DgN coefficients were evaluated. The results were compared with published data. Fit equations for the estimation of the G-factor parameter, introduced by the literature for converting the dose delivered in the heterogeneous medium to that in the glandular tissue, are proposed and the application of this parameter interaction-by-interaction or retrospectively is discussed. G4EmLivermorePhysicsList shows the best agreement for the linear attenuation coefficients both with theoretical values and published data. Moreover, excellent correlation factor ({{r}2}>0.99 ) is found for the DgN coefficients with the literature. The final goal of this study is to identify, for the first time, a benchmark of parameters that could be useful for future breast dosimetry studies with GEANT4.

  19. GEANT4 for breast dosimetry: parameters optimization study.

    PubMed

    Fedon, C; Longo, F; Mettivier, G; Longo, R

    2015-08-21

    Mean glandular dose (MGD) is the main dosimetric quantity in mammography. MGD evaluation is obtained by multiplying the entrance skin air kerma (ESAK) by normalized glandular dose (DgN) coefficients. While ESAK is an empirical quantity, DgN coefficients can only be estimated with Monte Carlo (MC) methods. Thus, a MC parameters benchmark is needed for effectively evaluating DgN coefficients. GEANT4 is a MC toolkit suitable for medical purposes that offers to the users several computational choices. In this work we investigate the GEANT4 performances testing the main PhysicsLists for medical applications. Four electromagnetic PhysicsLists were implemented: the linear attenuation coefficients were calculated for breast glandularity 0%, 50%, 100% in the energetic range 8-50 keV and DgN coefficients were evaluated. The results were compared with published data. Fit equations for the estimation of the G-factor parameter, introduced by the literature for converting the dose delivered in the heterogeneous medium to that in the glandular tissue, are proposed and the application of this parameter interaction-by-interaction or retrospectively is discussed. G4EmLivermorePhysicsList shows the best agreement for the linear attenuation coefficients both with theoretical values and published data. Moreover, excellent correlation factor (r2>0.99) is found for the DgN coefficients with the literature. The final goal of this study is to identify, for the first time, a benchmark of parameters that could be useful for future breast dosimetry studies with GEANT4. PMID:26267405

  20. Particles Production in Extensive Air Showers: GEANT4 vs CORSIKA

    NASA Astrophysics Data System (ADS)

    Sabra, M. S.; Watts, J. W.; Christl, M. J.

    2014-09-01

    Air shower simulations are essential tools for the interpretation of the Extensive Air Shower (EAS) measurements. The reliability of these codes is evaluated by comparisons with equivalent simulation calculations, and with experimental data (when available). In this work, we present GEANT4 calculations of particles production in EAS induced by primary protons and Iron in the PeV (1015 eV) energy range. The calculations, using different hadronic models, are compared with the results from the well-known air shower simulation code CORSIKA, and the results of this comparison will be discussed. Air shower simulations are essential tools for the interpretation of the Extensive Air Shower (EAS) measurements. The reliability of these codes is evaluated by comparisons with equivalent simulation calculations, and with experimental data (when available). In this work, we present GEANT4 calculations of particles production in EAS induced by primary protons and Iron in the PeV (1015 eV) energy range. The calculations, using different hadronic models, are compared with the results from the well-known air shower simulation code CORSIKA, and the results of this comparison will be discussed. This work is supported by the NASA Postdoctoral Program administered by Oak Ridge Associated Universities.

  1. Evaluation of open MPI and MPICH2 performances for the computation time in proton therapy dose calculations with Geant4

    NASA Astrophysics Data System (ADS)

    Kazemi, M.; Afarideh, H.; Riazi, Z.

    2015-11-01

    The aim of this research work is to use a better parallel software structure to improve the performance of the Monte Carlo Geant4 code in proton treatment planning. The hadron therapy simulation is rewritten to parallelize the shared memory multiprocessor systems by using the Message-Passing Interface (MPI). The speedup performance of the code has been studied by using two MPI-compliant libraries including Open MPI and the MPICH2, separately. Despite the speedup, the results are almost linear for both the Open MPI and MPICH2; the latter was chosen because of its better characteristics and lower computation time. The Geant4 parameters, including the step limiter and the set cut, have been analyzed to minimize the simulation time as much as possible. For a reasonable compromise between the spatial dose distribution and the calculation time, the improvement in time reduction coefficient reaches about 157.

  2. Software Architecture Design Reasoning

    NASA Astrophysics Data System (ADS)

    Tang, Antony; van Vliet, Hans

    Despite recent advancements in software architecture knowledge management and design rationale modeling, industrial practice is behind in adopting these methods. The lack of empirical proofs and the lack of a practical process that can be easily incorporated by practitioners are some of the hindrance for adoptions. In particular, the process to support systematic design reasoning is not available. To rectify this issue, we propose a design reasoning process to help architects cope with an architectural design environment where design concerns are cross-cutting and diversified.We use an industrial case study to validate that the design reasoning process can help improve the quality of software architecture design. The results have indicated that associating design concerns and identifying design options are important steps in design reasoning.

  3. Aircraft Design Software

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Successful commercialization of the AirCraft SYNThesis (ACSYNT) tool has resulted in the creation of Phoenix Integration, Inc. ACSYNT has been exclusively licensed to the company, an outcome of a seven year, $3 million effort to provide unique software technology to a focused design engineering market. Ames Research Center formulated ACSYNT and in working with the Virginia Polytechnic Institute CAD Laboratory, began to design and code a computer-aided design for ACSYNT. Using a Joint Sponsored Research Agreement, Ames formed an industry-government-university alliance to improve and foster research and development for the software. As a result of the ACSYNT Institute, the software is becoming a predominant tool for aircraft conceptual design. ACSYNT has been successfully applied to high- speed civil transport configuration, subsonic transports, and supersonic fighters.

  4. GEANT 4 simulation of (99)Mo photonuclear production in nanoparticles.

    PubMed

    Dikiy, N P; Dovbnya, A N; Fedorchenko, D V; Khazhmuradov, M A

    2016-08-01

    GEANT 4 Monte-Carlo simulation toolkit is used to study the kinematic recoil method of (99)Mo photonuclear production. Simulation for bremsstrahlung photon spectrum with maximum photon energy 30MeV showed that for MoO3 nanoparticle escape fraction decreases from 0.24 to 0.08 when nanoparticle size increases from 20nm to 80nm. For the natural molybdenum and pure (100)Mo we obtained the lower values: from 0.17 to 0.05. The generation of accompanying molybdenum nuclei is significantly lower for pure (100)Mo and is about 3.6 nuclei per single (99)Mo nucleus, while natural molybdenum nanoparticle produce about 48 accompanying nuclei. Also, we have shown that for high-energy photons escape fraction of (99)Mo decreases, while production of unwanted molybdenum isotopes is significantly higher. PMID:27156050

  5. Simulation of a Helical Channel using GEANT4

    SciTech Connect

    Elvira, V. D.; Lebrun, P.; Spentzouris, P.

    2001-02-01

    We present a simulation of a 72 m long cooling channel proposed by V. Balbekov based on the helical cooling concept developed by Ya. Derbenev. LiH wedge absorbers provide the energy loss mechanism and 201 MHz cavities are used for re-acceleration. They are placed inside a main solenoidal field to focus the beam. A helical field with an amplitude of 0.3 T and a period of 1.8 m provides momentum dispersion for emittance exchange.The simulation is performed using GEANT4. The total fractional transmission is 0.85, and the transverse, longitudinal, and 3-D cooling factors are 3.75, 2.27, and 14.61, respectively. Some version of this helical channel could eventually be used to replace the first section of the double flip channel to keep the longitudinal emittance under control and increase transmission. Although this is an interesting option, the technical challenges are still significant.

  6. Positron Production at JLab Simulated Using Geant4

    SciTech Connect

    Kossler, W. J.; Long, S. S.

    2009-09-02

    The results of a Geant4 Monte-Carlo study of the production of slow positrons using a 140 MeV electron beam which might be available at Jefferson Lab are presented. Positrons are produced by pair production for the gamma-rays produced by bremsstrahlung on the target which is also the stopping medium for the positrons. Positrons which diffuse to the surface of the stopping medium are assumed to be ejected due to a negative work function. Here the target and moderator are combined into one piece. For an osmium target/moderator 3 cm long with transverse dimensions of 1 cm by 1 mm, we obtain a slow positron yield of about 8.5centre dot10{sup 10}/(scentre dotmA) If these positrons were remoderated and re-emitted with a 23% probability we would obtain 2centre dot10{sup 10}/(scentre dotmA) in a micro-beam.

  7. Nuclear spectroscopy with Geant4: Proton and neutron emission & radioactivity

    NASA Astrophysics Data System (ADS)

    Sarmiento, L. G.; Rudolph, D.

    2016-07-01

    With the aid of a novel combination of existing equipment - JYFLTRAP and the TASISpec decay station - it is possible to perform very clean quantum-state selective, high-resolution particle-γ decay spectroscopy. We intend to study the determination of the branching ratio of the ℓ = 9 proton emission from the Iπ = 19/2-, 3174-keV isomer in the N = Z - 1 nucleus 53Co. The study aims to initiate a series of similar experiments along the proton dripline, thereby providing unique insights into "open quantum systems". The technique has been pioneered in case studies using SHIPTRAP and TASISpec at GSI. Newly available radioactive decay modes in Geant4 simulations are going to corroborate the anticipated experimental results.

  8. A modular Geant4 model of Leksell Gamma Knife Perfexion™

    NASA Astrophysics Data System (ADS)

    Pipek, J.; Novotný, J.; Novotný, J., Jr.; Kozubíková, P.

    2014-12-01

    This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase space files were created, containing particles that are entering the inner machine cavity after being transported through the collimation system. All 14 output factors of the machine and effective output factors for both the 4 mm (0.830 ± 0.009) and 8 mm (0.921 ± 0.004) collimators were calculated. Dose profiles along the main axes are also included for each collimator size. All results are compared to the values obtained from the treatment planning system, from experiments, and from other Monte Carlo models.

  9. Geant4 Simulation of Air Showers using Thinning Method

    NASA Astrophysics Data System (ADS)

    Sabra, Mohammad S.; Watts, John W.; Christl, Mark J.

    2015-04-01

    Simulation of complete air showers induced by cosmic ray particles becomes prohibitive at extreme energies due to the large number of secondary particles. Computing time of such simulations roughly scales with the energy of the primary cosmic ray particle, and becomes excessively large. To mitigate the problem, only small fraction of particles can be tracked and, then, the whole shower is reconstructed based on this sample. This method is called Thinning. Using this method in Geant4, we have simulated proton and iron air showers at extreme energies (E >1016 eV). Secondary particle densities are calculated and compared with the standard simulation program in this field, CORSIKA. This work is supported by the NASA Postdoctoral Program administrated by Oak Ridge Associated Universities.

  10. A modular Geant4 model of Leksell Gamma Knife Perfexion™.

    PubMed

    Pipek, J; Novotný, J; Novotný, J; Kozubíková, P

    2014-12-21

    This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase space files were created, containing particles that are entering the inner machine cavity after being transported through the collimation system. All 14 output factors of the machine and effective output factors for both the 4 mm (0.830 ± 0.009) and 8 mm (0.921 ± 0.004) collimators were calculated. Dose profiles along the main axes are also included for each collimator size. All results are compared to the values obtained from the treatment planning system, from experiments, and from other Monte Carlo models. PMID:25415510

  11. Aviation Design Software

    NASA Technical Reports Server (NTRS)

    1997-01-01

    DARcorporation developed a General Aviation CAD package through a Small Business Innovation Research contract from Langley Research Center. This affordable, user-friendly preliminary design system for General Aviation aircraft runs on the popular 486 IBM-compatible personal computers. Individuals taking the home-built approach, small manufacturers of General Aviation airplanes, as well as students and others interested in the analysis and design of aircraft are possible users of the package. The software can cut design and development time in half.

  12. Calibration and GEANT4 Simulations of the Phase II Proton Compute Tomography (pCT) Range Stack Detector

    SciTech Connect

    Uzunyan, S. A.; Blazey, G.; Boi, S.; Coutrakon, G.; Dyshkant, A.; Francis, K.; Hedin, D.; Johnson, E.; Kalnins, J.; Zutshi, V.; Ford, R.; Rauch, J. E.; Rubinov, P.; Sellberg, G.; Wilson, P.; Naimuddin, M.

    2015-12-29

    Northern Illinois University in collaboration with Fermi National Accelerator Laboratory (FNAL) and Delhi University has been designing and building a proton CT scanner for applications in proton treatment planning. The Phase II proton CT scanner consists of eight planes of tracking detectors with two X and two Y coordinate measurements both before and after the patient. In addition, a range stack detector consisting of a stack of thin scintillator tiles, arranged in twelve eight-tile frames, is used to determine the water equivalent path length (WEPL) of each track through the patient. The X-Y coordinates and WEPL are required input for image reconstruction software to find the relative (proton) stopping powers (RSP) value of each voxel in the patient and generate a corresponding 3D image. In this Note we describe tests conducted in 2015 at the proton beam at the Central DuPage Hospital in Warrenville, IL, focusing on the range stack calibration procedure and comparisons with the GEANT~4 range stack simulation.

  13. Monte Carlo application based on GEANT4 toolkit to simulate a laser-plasma electron beam line for radiobiological studies

    NASA Astrophysics Data System (ADS)

    Lamia, D.; Russo, G.; Casarino, C.; Gagliano, L.; Candiano, G. C.; Labate, L.; Baffigi, F.; Fulgentini, L.; Giulietti, A.; Koester, P.; Palla, D.; Gizzi, L. A.; Gilardi, M. C.

    2015-06-01

    We report on the development of a Monte Carlo application, based on the GEANT4 toolkit, for the characterization and optimization of electron beams for clinical applications produced by a laser-driven plasma source. The GEANT4 application is conceived so as to represent in the most general way the physical and geometrical features of a typical laser-driven accelerator. It is designed to provide standard dosimetric figures such as percentage dose depth curves, two-dimensional dose distributions and 3D dose profiles at different positions both inside and outside the interaction chamber. The application was validated by comparing its predictions to experimental measurements carried out on a real laser-driven accelerator. The work is aimed at optimizing the source, by using this novel application, for radiobiological studies and, in perspective, for medical applications.

  14. Balloon Design Software

    NASA Technical Reports Server (NTRS)

    Farley, Rodger

    2007-01-01

    PlanetaryBalloon Version 5.0 is a software package for the design of meridionally lobed planetary balloons. It operates in a Windows environment, and programming was done in Visual Basic 6. By including the effects of circular lobes with load tapes, skin mass, hoop and meridional stress, and elasticity in the structural elements, a more accurate balloon shape of practical construction can be determined as well as the room-temperature cut pattern for the gore shapes. The computer algorithm is formulated for sizing meridionally lobed balloons for any generalized atmosphere or planet. This also covers zero-pressure, over-pressure, and super-pressure balloons. Low circumferential loads with meridionally reinforced load tapes will produce shapes close to what are known as the "natural shape." The software allows for the design of constant angle, constant radius, or constant hoop stress balloons. It uses the desired payload capacity for given atmospheric conditions and determines the required volume, allowing users to design exactly to their requirements. The formulations are generalized to use any lift gas (or mixture of gases), any atmosphere, or any planet as described by the local acceleration of gravity. PlanetaryBalloon software has a comprehensive user manual that covers features ranging from, but not limited to, buoyancy and super-pressure, convenient design equations, shape formulation, and orthotropic stress/strain.

  15. Diffusion-controlled reactions modeling in Geant4-DNA

    SciTech Connect

    Karamitros, M.; Luan, S.; Bernal, M.A.; Allison, J.; Baldacchino, G.; Davidkova, M.; Francis, Z.; Friedland, W.; Ivantchenko, V.; Ivantchenko, A.; Mantero, A.; Nieminem, P.; Santin, G.; Tran, H.N.; Stepan, V.; Incerti, S.

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The

  16. Diffusion-controlled reactions modeling in Geant4-DNA

    NASA Astrophysics Data System (ADS)

    Karamitros, M.; Luan, S.; Bernal, M. A.; Allison, J.; Baldacchino, G.; Davidkova, M.; Francis, Z.; Friedland, W.; Ivantchenko, V.; Ivantchenko, A.; Mantero, A.; Nieminem, P.; Santin, G.; Tran, H. N.; Stepan, V.; Incerti, S.

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k-d tree data structure for quickly locating, for a given molecule, its closest reactants. The

  17. GATE - Geant4 Application for Tomographic Emission: a simulation toolkit for PET and SPECT

    PubMed Central

    Jan, S.; Santin, G.; Strul, D.; Staelens, S.; Assié, K.; Autret, D.; Avner, S.; Barbier, R.; Bardiès, M.; Bloomfield, P. M.; Brasse, D.; Breton, V.; Bruyndonckx, P.; Buvat, I.; Chatziioannou, A. F.; Choi, Y.; Chung, Y. H.; Comtat, C.; Donnarieix, D.; Ferrer, L.; Glick, S. J.; Groiselle, C. J.; Guez, D.; Honore, P.-F.; Kerhoas-Cavata, S.; Kirov, A. S.; Kohli, V.; Koole, M.; Krieguer, M.; van der Laan, D. J.; Lamare, F.; Largeron, G.; Lartizien, C.; Lazaro, D.; Maas, M. C.; Maigne, L.; Mayet, F.; Melot, F.; Merheb, C.; Pennacchio, E.; Perez, J.; Pietrzyk, U.; Rannou, F. R.; Rey, M.; Schaart, D. R.; Schmidtlein, C. R.; Simon, L.; Song, T. Y.; Vieira, J.-M.; Visvikis, D.; Van de Walle, R.; Wieërs, E.; Morel, C.

    2012-01-01

    Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols, and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document, and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at the address http://www-lphe.ep.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects toward the gridification of GATE and its extension to other domains such as dosimetry are also discussed. PMID:15552416

  18. Thermal neutron response of a boron-coated GEM detector via GEANT4 Monte Carlo code.

    PubMed

    Jamil, M; Rhee, J T; Kim, H G; Ahmad, Farzana; Jeon, Y J

    2014-10-22

    In this work, we report the design configuration and the performance of the hybrid Gas Electron Multiplier (GEM) detector. In order to make the detector sensitive to thermal neutrons, the forward electrode of the GEM has been coated with the enriched boron-10 material, which works as a neutron converter. A total of 5×5cm(2) configuration of GEM has been used for thermal neutron studies. The response of the detector has been estimated via using GEANT4 MC code with two different physics lists. Using the QGSP_BIC_HP physics list, the neutron detection efficiency was determined to be about 3%, while with QGSP_BERT_HP physics list the efficiency was around 2.5%, at the incident thermal neutron energies of 25meV. The higher response of the detector proves that GEM-coated with boron converter improves the efficiency for thermal neutrons detection. PMID:25464183

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

    PubMed

    Bernal, M A; Bordage, M C; Brown, J M C; Davídková, M; Delage, E; El Bitar, Z; Enger, S A; Francis, Z; Guatelli, S; Ivanchenko, V N; Karamitros, M; Kyriakou, I; Maigne, L; Meylan, S; Murakami, K; Okada, S; Payno, H; Perrot, Y; Petrovic, I; Pham, Q T; Ristic-Fira, A; Sasaki, T; Štěpán, V; Tran, H N; Villagrasa, C; Incerti, S

    2015-12-01

    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. PMID:26653251

  20. Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV

    NASA Astrophysics Data System (ADS)

    Maigne, L.; Perrot, Y.; Schaart, D. R.; Donnarieix, D.; Breton, V.

    2011-02-01

    The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV.

  1. Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV.

    PubMed

    Maigne, L; Perrot, Y; Schaart, D R; Donnarieix, D; Breton, V

    2011-02-01

    The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV. PMID:21239846

  2. Experimental quantification of Geant4 PhysicsList recommendations: methods and results

    NASA Astrophysics Data System (ADS)

    Basaglia, Tullio; Han, Min Cheol; Hoff, Gabriela; Kim, Chan Hyeong; Kim, Sung Hun; Grazia Pia, Maria; Saracco, Paolo

    2015-12-01

    The Geant4 physicsjists package encompasses predefined selections of physics processes and models to be used in simulation applications. Limited documentation is available in the literature about Geant4 pre-packaged PhysicsLists and their validation. The reports in the literature mainly concern specific use cases. This paper documents the epistemological grounds for the validation of Geant4 pre-packaged PhysicsLists (and their accessory classes, Builders and PhysicsConstructors) and some examples of the author's scientific activity on this subject.

  3. Software-Design-Analyzer System

    NASA Technical Reports Server (NTRS)

    Tausworthe, Robert C.

    1991-01-01

    CRISP-90 software-design-analyzer system, update of CRISP-80, is set of computer programs constituting software tool for design and documentation of other software and supporting top-down, hierarchical, modular, structured methodologies for design and programming. Written in Microsoft QuickBasic.

  4. Designing Educational Software for Tomorrow.

    ERIC Educational Resources Information Center

    Harvey, Wayne

    Designed to address the management and use of computer software in education and training, this paper explores both good and poor software design, calling for improvements in the quality of educational software by attending to design considerations that are based on general principles of learning rather than specific educational objectives. This…

  5. Scatter in an uncollimated x-ray CT machine based on a Geant4 Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Wadeson, Nicola; Morton, Edward; Lionheart, William

    2010-04-01

    A high-speed motionless-gantry x-ray CT machine has been designed to allow for 3D images to be collected in real time. By using multiple, switched x-ray sources and fixed detector rings, the time consuming mechanical rotation of conventional CT machines can be removed. However, the nature of this design limits the possibility of detector collimation since each detector must now be able to record the energy of x-ray beams from a number of different directions. The lack of collimation has implications in the reconstructed image due to an increase in the number of scattered photons recorded. A Monte Carlo computer simulation of the x-ray machine has been developed, using the Geant4 software toolkit, to analyse the behaviour of both Rayleigh and Compton scattered photons when considering airport baggage and medical applications. Four different scattering objects were analysed based on 50kVp, 100kVp and 150kVp spectra for a tungsten target. Two suitcase objects, a body and a brain phantom were chosen as objects typical of airport baggage and medical CT. The results indicate that the level of scatter is negligible for a typical airport baggage application, since the majority of space in a suitcase consists of clothing, which has a low density. Scatter contributes to less than 1% of the image in all instances. However, due to the large amounts of water found in the human body, the level of scatter in the medical instances are significantly higher, reaching 37% when the body phantom is analysed at 50kVp.

  6. Hadronic models validation in GEANT4 with CALICE highly granular calorimeters

    NASA Astrophysics Data System (ADS)

    Ramilli, Marco; CALICE Collaboration

    2012-12-01

    The CALICE collaboration has constructed highly granular hadronic and electromagnetic calorimeter prototypes to evaluate technologies for the use in detector systems at a future Linear Collider, and to validate hadronic shower models with unprecedented spatial segmentation. The electromagnetic calorimeter is a sampling structure of tungsten and silicon with 9720 readout channels. The hadron calorimeter uses 7608 small plastic scintillator cells individually read out with silicon photomultipliers. This high granularity opens up the possibility for precise three-dimensional shower reconstructions and for software compensation techniques to improve the energy resolution of the detector. We discuss the latest results on the studies of shower shapes and shower properties and the comparison to the latest developed GEANT4 models for hadronic showers. A satisfactory agreement at better than 5% is found between data and simulations for most of the investigated variables. We show that applying software compensation methods based on reconstructed clusters the energy resolution for hadrons improves by a factor of 15%. The next challenge for CALICE calorimeters will be to validate the 4th dimension of hadronic showers, namely their time evolution.

  7. Apply Design Patterns to Refactor Software Design

    NASA Technical Reports Server (NTRS)

    Baggs, Rhoda; Shaykhian, Gholam Ali

    2007-01-01

    Refactoring software design is a method of changing software design while explicitly preserving its unique design functionalities. Presented approach is to utilize design patterns as the basis for refactoring software design. Comparison of a design solution will be made through C++ programming language examples to exploit this approach. Developing reusable component will be discussed, the paper presents that the construction of such components can diminish the added burden of both refactoring and the use of design patterns.

  8. Study on GEANT4 code applications to dose calculation using imaging data

    NASA Astrophysics Data System (ADS)

    Lee, Jeong Ok; Kang, Jeong Ku; Kim, Jhin Kee; Kwon, Hyeong Cheol; Kim, Jung Soo; Kim, Bu Gil; Jeong, Dong Hyeok

    2015-07-01

    The use of the GEANT4 code has increased in the medical field. Various studies have calculated the patient dose distributions by users the GEANT4 code with imaging data. In present study, Monte Carlo simulations based on DICOM data were performed to calculate the dose absorb in the patient's body. Various visualization tools are installed in the GEANT4 code to display the detector construction; however, the display of DICOM images is limited. In addition, to displaying the dose distributions on the imaging data of the patient is difficult. Recently, the gMocren code, a volume visualization tool for GEANT4 simulation, was developed and has been used in volume visualization of image files. In this study, the imaging based on the dose distributions absorbed in the patients was performed by using the gMocren code. Dosimetric evaluations with were carried out by using thermo luminescent dosimeter and film dosimetry to verify the calculated results.

  9. Physical models implemented in the GEANT4-DNA extension of the GEANT-4 toolkit for calculating initial radiation damage at the molecular level.

    PubMed

    Villagrasa, C; Francis, Z; Incerti, S

    2011-02-01

    The ROSIRIS project aims to study the radiobiology of integrated systems for medical treatment optimisation using ionising radiations and evaluate the associated risk. In the framework of this project, one research focus is the interpretation of the initial radio-induced damage in DNA created by ionising radiation (and detected by γ-H2AX foci analysis) from the track structure of the incident particles. In order to calculate the track structure of ionising particles at a nanometric level, the Geant4 Monte Carlo toolkit was used. Geant4 (Object Oriented Programming Architecture in C++) offers a common platform, available free to all users and relatively easy to use. Nevertheless, the current low-energy threshold for electromagnetic processes in GEANT4 is set to 1 keV (250 eV using the Livermore processes), which is an unsuitable value for nanometric applications. To lower this energy threshold, the necessary interaction processes and models were identified, and the corresponding available cross sections collected from the literature. They are mostly based on the plane-wave Born approximation (first Born approximation, or FBA) for inelastic interactions and on semi-empirical models for energies where the FBA fails (at low energies). In this paper, the extensions that have been introduced into the 9.3 release of the Geant4 toolkit are described, the so-called Geant4-DNA extension, including a set of processes and models adapted in this study and permitting the simulation of electron (8 eV-1 MeV), proton (100 eV-100 MeV) and alpha particle (1 keV-10 MeV) interactions in liquid water. PMID:21186212

  10. Refined lateral energy correction functions for the KASCADE-Grande experiment based on Geant4 simulations

    NASA Astrophysics Data System (ADS)

    Gherghel-Lascu, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-02-01

    In previous studies of KASCADE-Grande data, a Monte Carlo simulation code based on the GEANT3 program has been developed to describe the energy deposited by EAS particles in the detector stations. In an attempt to decrease the simulation time and ensure compatibility with the geometry description in standard KASCADE-Grande analysis software, several structural elements have been neglected in the implementation of the Grande station geometry. To improve the agreement between experimental and simulated data, a more accurate simulation of the response of the KASCADE-Grande detector is necessary. A new simulation code has been developed based on the GEANT4 program, including a realistic geometry of the detector station with structural elements that have not been considered in previous studies. The new code is used to study the influence of a realistic detector geometry on the energy deposited in the Grande detector stations by particles from EAS events simulated by CORSIKA. Lateral Energy Correction Functions are determined and compared with previous results based on GEANT3.

  11. Applying Software Design Methodology to Instructional Design

    ERIC Educational Resources Information Center

    East, J. Philip

    2004-01-01

    The premise of this paper is that computer science has much to offer the endeavor of instructional improvement. Software design processes employed in computer science for developing software can be used for planning instruction and should improve instruction in much the same manner that design processes appear to have improved software. Techniques…

  12. Desiderata for Linguistic Software Design

    ERIC Educational Resources Information Center

    Garretson, Gregory

    2008-01-01

    This article presents a series of guidelines both for researchers in search of software to be used in linguistic analysis and for programmers designing such software. A description of the intended audience and the types of software under consideration and a review of some relevant literature are followed by a discussion of several important…

  13. A Learning Software Design Competition.

    ERIC Educational Resources Information Center

    Hooper, Simon; Hokanson, Brad; Bernhardt, Paul; Johnson, Mark

    2002-01-01

    Explains the University of Minnesota Learning Software Design Competition, focusing on its goals and emphasis on innovation. Describes the review process to evaluate and judge the software, lists the winners, identifies a new class of educational software, and outlines plans for future competitions. (Author/LRW)

  14. Validation of a small-animal PET simulation using GAMOS: a GEANT4-based framework

    NASA Astrophysics Data System (ADS)

    Cañadas, M.; Arce, P.; Rato Mendes, P.

    2011-01-01

    Monte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250-750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL-1 and the simulated peak was

  15. SDDL: Software Design Documentation Language

    NASA Technical Reports Server (NTRS)

    Kleine, H.; Callender, D. E.; Zepko, T. M.

    1985-01-01

    Promotes effective communications between software designer and user. SDDL successful on tasks ranging from small, one-person informal projects to large projects of hundreds of formally published pages of design.

  16. Use of GEANT4 vs. MCNPX for the characterization of a boron-lined neutron detector

    NASA Astrophysics Data System (ADS)

    van der Ende, B. M.; Atanackovic, J.; Erlandson, A.; Bentoumi, G.

    2016-06-01

    This work compares GEANT4 with MCNPX in the characterization of a boron-lined neutron detector. The neutron energy ranges simulated in this work (0.025 eV to 20 MeV) are the traditional domain of MCNP simulations. This paper addresses the question, how well can GEANT4 and MCNPX be employed for detailed thermal neutron detector characterization? To answer this, GEANT4 and MCNPX have been employed to simulate detector response to a 252Cf energy spectrum point source, as well as to simulate mono-energetic parallel beam source geometries. The 252Cf energy spectrum simulation results demonstrate agreement in detector count rate within 3% between the two packages, with the MCNPX results being generally closer to experiment than are those from GEANT4. The mono-energetic source simulations demonstrate agreement in detector response within 5% between the two packages for all neutron energies, and within 1% for neutron energies between 100 eV and 5 MeV. Cross-checks between the two types of simulations using ISO-8529 252Cf energy bins demonstrates that MCNPX results are more self-consistent than are GEANT4 results, by 3-4%.

  17. Geant4 simulation of the CERN-EU high-energy reference field (CERF) facility.

    PubMed

    Prokopovich, D A; Reinhard, M I; Cornelius, I M; Rosenfeld, A B

    2010-09-01

    The CERN-EU high-energy reference field facility is used for testing and calibrating both active and passive radiation dosemeters for radiation protection applications in space and aviation. Through a combination of a primary particle beam, target and a suitable designed shielding configuration, the facility is able to reproduce the neutron component of the high altitude radiation field relevant to the jet aviation industry. Simulations of the facility using the GEANT4 (GEometry ANd Tracking) toolkit provide an improved understanding of the neutron particle fluence as well as the particle fluence of other radiation components present. The secondary particle fluence as a function of the primary particle fluence incident on the target and the associated dose equivalent rates were determined at the 20 designated irradiation positions available at the facility. Comparisons of the simulated results with previously published simulations obtained using the FLUKA Monte Carlo code, as well as with experimental results of the neutron fluence obtained with a Bonner sphere spectrometer, are made. PMID:20511404

  18. Designing Good Educational Software.

    ERIC Educational Resources Information Center

    Kingman, James C.

    1984-01-01

    Describes eight characteristics of good educational software. They are: (1) educational soundness; (2) ease of use; (3) "bullet" proofing (preventing a program from coming to a premature halt); (4) clear instructions; (5) appropriate language; (6) appropriate frame size; (7) motivation; and (8) evaluation. (JN)

  19. Geant4 electromagnetic physics for the LHC and other HEP applications

    NASA Astrophysics Data System (ADS)

    Schälicke, Andreas; Bagulya, Alexander; Dale, Ørjan; Dupertuis, Frederic; Ivanchenko, Vladimir; Kadri, Omrane; Lechner, Anton; Maire, Michel; Tsagri, Mary; Urban, Laszlo

    2011-12-01

    An overview of the electromagnetic physics (EM) models available in the Geant4 toolkit is presented. Recent improvements are focused on the performance of detector simulation results from large MC production exercises at the LHC. Significant efforts were spent for high statistics validation of EM physics. The work on consolidation of Geant4 EM physics was achieved providing common interfaces for EM standard (HEP oriented) and EM low-energy models (other application domains). It allows the combination of ultra-relativistic, relativistic and low-energy models for any Geant4 EM processes. With such a combination both precision and CPU performance are achieved for the simulation of EM interactions in a wide energy range. Due to this migration of EM low-energy models to the common interface additional capabilities become available. Selected validation results are presented in this contribution.

  20. Application of GEANT4 radiation transport toolkit to dose calculations in anthropomorphic phantoms.

    PubMed

    Rodrigues, P; Trindade, A; Peralta, L; Alves, C; Chaves, A; Lopes, M C

    2004-12-01

    In this paper, we present a novel implementation of a dose calculation application, based on the GEANT4 Monte Carlo toolkit. Validation studies were performed with an homogeneous water phantom and an Alderson-Rando anthropomorphic phantom both irradiated with high-energy photon beams produced by a clinical linear accelerator. As input, this tool requires computer tomography images for automatic codification of voxel-based geometries and phase-space distributions to characterize the incident radiation field. Simulation results were compared with ionization chamber, thermoluminescent dosimetry data and commercial treatment planning system calculations. In homogeneous water phantom, overall agreement with measurements were within 1-2%. For anthropomorphic simulated setups (thorax and head irradiation) mean differences between GEANT4 and TLD measurements were less than 2%. Significant differences between GEANT4 and a semi-analytical algorithm implemented in the treatment planning system, were found in low-density regions, such as air cavities with strong electronic disequilibrium. PMID:15388147

  1. Calculation of electron Dose Point Kernel in water with GEANT4 for medical application

    NASA Astrophysics Data System (ADS)

    Guimarães, C. C.; Moralles, M.; Sene, F. F.; Martinelli, J. R.; Okuno, E.

    2009-06-01

    The rapid insertion of new technologies in medical physics in the last years, especially in nuclear medicine, has been followed by a great development of faster Monte Carlo algorithms. GEANT4 is a Monte Carlo toolkit that contains the tools to simulate the problems of particle transport through matter. In this work, GEANT4 was used to calculate the dose-point-kernel (DPK) for monoenergetic electrons in water, which is an important reference medium for nuclear medicine. The three different physical models of electromagnetic interactions provided by GEANT4—Low Energy, Penelope and Standard—were employed. To verify the adequacy of these models, the results were compared with references from the literature. For all energies and physical models, the agreement between calculated DPKs and reported values is satisfactory.

  2. Dose conversion coefficients for ICRP110 voxel phantom in the Geant4 Monte Carlo code

    NASA Astrophysics Data System (ADS)

    Martins, M. C.; Cordeiro, T. P. V.; Silva, A. X.; Souza-Santos, D.; Queiroz-Filho, P. P.; Hunt, J. G.

    2014-02-01

    The reference adult male voxel phantom recommended by International Commission on Radiological Protection no. 110 was implemented in the Geant4 Monte Carlo code. Geant4 was used to calculate Dose Conversion Coefficients (DCCs) expressed as dose deposited in organs per air kerma for photons, electrons and neutrons in the Annals of the ICRP. In this work the AP and PA irradiation geometries of the ICRP male phantom were simulated for the purpose of benchmarking the Geant4 code. Monoenergetic photons were simulated between 15 keV and 10 MeV and the results were compared with ICRP 110, the VMC Monte Carlo code and the literature data available, presenting a good agreement.

  3. Microdosimetry of the Auger electron emitting 123I radionuclide using Geant4-DNA simulations

    NASA Astrophysics Data System (ADS)

    Fourie, H.; Newman, R. T.; Slabbert, J. P.

    2015-04-01

    Microdosimetric calculations of the Auger electron emitter 123I were done in liquid water spheres using the Geant4 toolkit. The electron emission spectrum of 123I produced by Geant4 is presented. Energy deposition and corresponding S-values were calculated to investigate the influence of the sub-cellular localization of the Auger emitter. It was found that S-values calculated by the Geant4 toolkit are generally lower than the values calculated by other Monte Carlo codes for the 123I radionuclide. The differences in the compared S-values are mainly due to the different particle emission spectra employed by the respective computational codes and emphasizes the influence of the spectra on dosimetry calculations.

  4. Microdosimetry of the Auger electron emitting 123I radionuclide using Geant4-DNA simulations.

    PubMed

    Fourie, H; Newman, R T; Slabbert, J P

    2015-04-21

    Microdosimetric calculations of the Auger electron emitter (123)I were done in liquid water spheres using the Geant4 toolkit. The electron emission spectrum of (123)I produced by Geant4 is presented. Energy deposition and corresponding S-values were calculated to investigate the influence of the sub-cellular localization of the Auger emitter. It was found that S-values calculated by the Geant4 toolkit are generally lower than the values calculated by other Monte Carlo codes for the (123)I radionuclide. The differences in the compared S-values are mainly due to the different particle emission spectra employed by the respective computational codes and emphasizes the influence of the spectra on dosimetry calculations. PMID:25825914

  5. Geant4 simulation of the response of phosphor screens for X-ray imaging

    NASA Astrophysics Data System (ADS)

    Pistrui-Maximean, S. A.; Freud, N.; Létang, J. M.; Koch, A.; Munier, B.; Walenta, A. H.; Montarou, G.; Babot, D.

    2006-07-01

    In order to predict and optimize the response of phosphor screens, it is important to understand the role played by the different physical processes inside the scintillator layer. A simulation model based on the Monte Carlo code Geant4 was developed to determine the Modulation Transfer Function (MTF) of phosphor screens for energies used in X-ray medical imaging and nondestructive testing applications. The visualization of the dose distribution inside the phosphor layer gives an insight into how the MTF is progressively degraded by X-ray and electron transport. The simulation model allows to study the influence of physical and technological parameters on the detector performances, as well as to design and optimize new detector configurations. Preliminary MTF measurements have been carried out and agreement with experimental data has been found in the case of a commercial screen (Kodak Lanex Fine) at an X-ray tube potential of 100 kV. Further validation with other screens (transparent or granular) at different energies is under way.

  6. Applying Software Design Methodology to Instructional Design

    NASA Astrophysics Data System (ADS)

    East, J. Philip

    2004-12-01

    The premise of this paper is that computer science has much to offer the endeavor of instructional improvement. Software design processes employed in computer science for developing software can be used for planning instruction and should improve instruction in much the same manner that design processes appear to have improved software. Techniques for examining the software development process can be applied to an examination of the instructional process. Furthermore, the computer science discipline is particularly well suited to these tasks. Thus, computer science can develop instructional design expertise for export to other disciplines to improve education in all disciplines and, eventually, at all levels.

  7. Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4

    PubMed Central

    Skeltved, Alexander Broberg; Østgaard, Nikolai; Carlson, Brant; Gjesteland, Thomas; Celestin, Sebastien

    2014-01-01

    This paper presents the first study that uses the GEometry ANd Tracking 4 (GEANT4) toolkit to do quantitative comparisons with other modeling results related to the production of terrestrial gamma ray flashes and high-energy particle emission from thunderstorms. We will study the relativistic runaway electron avalanche (RREA) and the relativistic feedback process, as well as the production of bremsstrahlung photons from runaway electrons. The Monte Carlo simulations take into account the effects of electron ionization, electron by electron (Møller), and electron by positron (Bhabha) scattering as well as the bremsstrahlung process and pair production, in the 250 eV to 100 GeV energy range. Our results indicate that the multiplication of electrons during the development of RREAs and under the influence of feedback are consistent with previous estimates. This is important to validate GEANT4 as a tool to model RREAs and feedback in homogeneous electric fields. We also determine the ratio of bremsstrahlung photons to energetic electrons Nγ/Ne. We then show that the ratio has a dependence on the electric field, which can be expressed by the avalanche time τ(E) and the bremsstrahlung coefficient α(ε). In addition, we present comparisons of GEANT4 simulations performed with a “standard” and a “low-energy” physics list both validated in the 1 keV to 100 GeV energy range. This comparison shows that the choice of physics list used in GEANT4 simulations has a significant effect on the results. Key Points Testing the feedback mechanism with GEANT4 Validating the GEANT4 programming toolkit Study the ratio of bremsstrahlung photons to electrons at TGF source altitude PMID:26167437

  8. Response of a proportional counter to 37Ar and 71Ge: Measured spectra versus Geant4 simulation

    NASA Astrophysics Data System (ADS)

    Abdurashitov, D. N.; Malyshkin, Yu. M.; Matushko, V. L.; Suerfu, B.

    2016-04-01

    The energy deposition spectra of 37Ar and 71Ge in a miniature proportional counter are measured and compared in detail to the model response simulated with Geant4. A certain modification of the Geant4 code, making it possible to trace the deexcitation of atomic shells properly, is suggested. Modified Geant4 is able to reproduce a response of particle detectors in detail in the keV energy range. This feature is very important for the laboratory experiments that search for massive sterile neutrinos as well as for dark matter searches that employ direct detection of recoil nuclei. This work demonstrates the reliability of Geant4 simulation at low energies.

  9. Software design and documentation language

    NASA Technical Reports Server (NTRS)

    Kleine, H.

    1980-01-01

    Language supports design and documentation of complex software. Included are: design and documentation language for expressing design concepts; processor that produces intelligble documentation based on design specifications; and methodology for using language and processor to create well-structured top-down programs and documentation. Processor is written in SIMSCRIPT 11.5 programming language for use on UNIVAC, IBM, and CDC machines.

  10. A Student Project to use Geant4 Simulations for a TMS-PET combination

    SciTech Connect

    Altamirano, A.; Chamorro, A.; Hurtado, K.; Romero, C.; Wahl, D.; Zamudio, A.; Rueda, A.; Solano Salinas, C. J.

    2007-10-26

    Geant4 is one of the most powerful tools for MC simulation of detectors and their applications. We present a student project to simulate a combined Transcranial Magnetic Stimulation-Positron Emission Tomography (TMS-PET) system using Geant4. This project aims to study PET-TMS systems by implementing a model for the brain response to the TMS pulse and studying the simulated PET response. In order to increase the speed of the simulations we parallelise our programs and investigate the possibility of using GRID computing.

  11. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    SciTech Connect

    Perrot, Y; Payno, H; Delage, E; Maigne, L

    2014-06-01

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  12. Echelle spectrograph software design aid

    NASA Technical Reports Server (NTRS)

    Dantzler, A. A.

    1985-01-01

    A method for mapping, to first order, the spectrograms that result from echelle spectrographic systems is discussed. An in-depth description of the principles behind the method are given so that software may be generated. Such software is an invaluable echelle spectrograph design aid. Results from two applications are discussed.

  13. Reflight certification software design specifications

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The PDSS/IMC Software Design Specification for the Payload Development Support System (PDSS)/Image Motion Compensator (IMC) is contained. The PDSS/IMC is to be used for checkout and verification of the IMC flight hardware and software by NASA/MSFC.

  14. Measurement of depth-dose of linear accelerator and simulation by use of Geant4 computer code

    PubMed Central

    Sardari, D.; Maleki, R.; Samavat, H.; Esmaeeli, A.

    2010-01-01

    Radiation therapy is an established method of cancer treatment. New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapy treatment plan. This study presents some results of a Geant4-based application for simulation of the absorbed dose distribution given by a medical linear accelerator (LINAC). The LINAC geometry is accurately described in the Monte Carlo code with use of the accelerator manufacturer's specifications. The capability of the software for evaluating the dose distribution has been verified by comparisons with measurements in a water phantom; the comparisons were performed for percentage depth dose (PDD) and profiles for various field sizes and depths, for a 6-MV electron beam. Experimental and calculated dose values were in good agreement both in PDD and in transverse sections of the water phantom. PMID:24376926

  15. Simulating cosmic radiation absorption and secondary particle production of solar panel layers of Low Earth Orbit (LEO) satellite with GEANT4

    NASA Astrophysics Data System (ADS)

    Yiǧitoǧlu, Merve; Veske, Doǧa; Nilüfer Öztürk, Zeynep; Bilge Demirköz, Melahat

    2016-07-01

    All devices which operate in space are exposed to cosmic rays during their operation. The resulting radiation may cause fatal damages in the solid structure of devices and the amount of absorbed radiation dose and secondary particle production for each component should be calculated carefully before the production. Solar panels are semiconductor solid state devices and are very sensitive to radiation. Even a short term power cut-off may yield a total failure of the satellite. Even little doses of radiation can change the characteristics of solar cells. This deviation can be caused by rarer high energetic particles as well as the total ionizing dose from the abundant low energy particles. In this study, solar panels planned for a specific LEO satellite, IMECE, are analyzed layer by layer. The Space Environment Information System (SPENVIS) database and GEANT4 simulation software are used to simulate the layers of the panels. The results obtained from the simulation will be taken in account to determine the amount of radiation protection and resistance needed for the panels or to revise the design of the panels.

  16. Software design and documentation language

    NASA Technical Reports Server (NTRS)

    Kleine, H.

    1977-01-01

    A communications medium to support the design and documentation of complex software applications is studied. The medium also provides the following: (1) a processor which can convert design specifications into an intelligible, informative machine reproducible document; (2) a design and documentation language with forms and syntax that are simple, unrestrictive, and communicative; and (3) methodology for effective use of the language and processor.

  17. CMS validation experience: Test-beam 2004 data vs GEANT4

    SciTech Connect

    Piperov, Stefan; /Fermilab /Sofiya, Inst. Nucl. Res.

    2007-01-01

    A comparison between the Geant4 Monte-Carlo simulation of CMS Detector's Calorimetric System and data from the 2004 Test-Beam at CERN's SPS H2 beam-line is presented. The overall simulated response agrees quite well with the measured response. Slight differences in the longitudinal shower profiles between the MC predictions made with different Physics Lists are observed.

  18. Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4

    NASA Astrophysics Data System (ADS)

    Skeltved, Alexander Broberg; Østgaard, Nikolai; Carlson, Brant; Gjesteland, Thomas; Celestin, Sebastien

    2014-11-01

    This paper presents the first study that uses the GEometry ANd Tracking 4 (GEANT4) toolkit to do quantitative comparisons with other modeling results related to the production of terrestrial gamma ray flashes and high-energy particle emission from thunderstorms. We will study the relativistic runaway electron avalanche (RREA) and the relativistic feedback process, as well as the production of bremsstrahlung photons from runaway electrons. The Monte Carlo simulations take into account the effects of electron ionization, electron by electron (Møller), and electron by positron (Bhabha) scattering as well as the bremsstrahlung process and pair production, in the 250 eV to 100 GeV energy range. Our results indicate that the multiplication of electrons during the development of RREAs and under the influence of feedback are consistent with previous estimates. This is important to validate GEANT4 as a tool to model RREAs and feedback in homogeneous electric fields. We also determine the ratio of bremsstrahlung photons to energetic electrons Nγ/Ne. We then show that the ratio has a dependence on the electric field, which can be expressed by the avalanche time τ(E) and the bremsstrahlung coefficient α(ɛ). In addition, we present comparisons of GEANT4 simulations performed with a "standard" and a "low-energy" physics list both validated in the 1 keV to 100 GeV energy range. This comparison shows that the choice of physics list used in GEANT4 simulations has a significant effect on the results.

  19. Identifying key surface parameters for optical photon transport in GEANT4/GATE simulations.

    PubMed

    Nilsson, Jenny; Cuplov, Vesna; Isaksson, Mats

    2015-09-01

    For a scintillator used for spectrometry, the generation, transport and detection of optical photons have a great impact on the energy spectrum resolution. A complete Monte Carlo model of a scintillator includes a coupled ionizing particle and optical photon transport, which can be simulated with the GEANT4 code. The GEANT4 surface parameters control the physics processes an optical photon undergoes when reaching the surface of a volume. In this work the impact of each surface parameter on the optical transport was studied by looking at the optical spectrum: the number of detected optical photons per ionizing source particle from a large plastic scintillator, i.e. the output signal. All simulations were performed using GATE v6.2 (GEANT4 Application for Tomographic Emission). The surface parameter finish (polished, ground, front-painted or back-painted) showed the greatest impact on the optical spectrum whereas the surface parameter σ(α), which controls the surface roughness, had a relatively small impact. It was also shown how the surface parameters reflectivity and reflectivity types (specular spike, specular lobe, Lambertian and backscatter) changed the optical spectrum depending on the probability for reflection and the combination of reflectivity types. A change in the optical spectrum will ultimately have an impact on a simulated energy spectrum. By studying the optical spectra presented in this work, a GEANT4 user can predict the shift in an optical spectrum caused be the alteration of a specific surface parameter. PMID:26046519

  20. Simulating response functions and pulse shape discrimination for organic scintillation detectors with Geant4

    NASA Astrophysics Data System (ADS)

    Hartwig, Zachary S.; Gumplinger, Peter

    2014-02-01

    We present new capabilities of the Geant4 toolkit that enable the precision simulation of organic scintillation detectors within a comprehensive Monte Carlo code for the first time. As of version 10.0-beta, the Geant4 toolkit models the data-driven photon production from any user-defined scintillator, photon transportation through arbitrarily complex detector geometries, and time-resolved photon detection at the light readout device. By fully specifying the optical properties and geometrical configuration of the detector, the user can simulate response functions, photon transit times, and pulse shape discrimination. These capabilities enable detector simulation within a larger experimental environment as well as computationally evaluating novel scintillators, detector geometry, and light readout configurations. We demonstrate agreement of Geant4 with the NRESP7 code and with experiments for the spectroscopy of neutrons and gammas in the ranges 0-20 MeV and 0.511-1.274 MeV, respectively, using EJ301-based organic scintillation detectors. We also show agreement between Geant4 and experimental modeling of the particle-dependent detector pulses that enable simulated pulse shape discrimination.

  1. Applications of the Monte Carlo method in nuclear physics using the GEANT4 toolkit

    SciTech Connect

    Moralles, Mauricio; Guimaraes, Carla C.; Menezes, Mario O.; Bonifacio, Daniel A. B.; Okuno, Emico; Guimaraes, Valdir; Murata, Helio M.; Bottaro, Marcio

    2009-06-03

    The capabilities of the personal computers allow the application of Monte Carlo methods to simulate very complex problems that involve the transport of particles through matter. Among the several codes commonly employed in nuclear physics problems, the GEANT4 has received great attention in the last years, mainly due to its flexibility and possibility to be improved by the users. Differently from other Monte Carlo codes, GEANT4 is a toolkit written in object oriented language (C++) that includes the mathematical engine of several physical processes, which are suitable to be employed in the transport of practically all types of particles and heavy ions. GEANT4 has also several tools to define materials, geometry, sources of radiation, beams of particles, electromagnetic fields, and graphical visualization of the experimental setup. After a brief description of the GEANT4 toolkit, this presentation reports investigations carried out by our group that involve simulations in the areas of dosimetry, nuclear instrumentation and medical physics. The physical processes available for photons, electrons, positrons and heavy ions were used in these simulations.

  2. Applications of the Monte Carlo method in nuclear physics using the GEANT4 toolkit

    NASA Astrophysics Data System (ADS)

    Moralles, Maurício; Guimarães, Carla C.; Bonifácio, Daniel A. B.; Okuno, Emico; Murata, Hélio M.; Bottaro, Márcio; Menezes, Mário O.; Guimarães, Valdir

    2009-06-01

    The capabilities of the personal computers allow the application of Monte Carlo methods to simulate very complex problems that involve the transport of particles through matter. Among the several codes commonly employed in nuclear physics problems, the GEANT4 has received great attention in the last years, mainly due to its flexibility and possibility to be improved by the users. Differently from other Monte Carlo codes, GEANT4 is a toolkit written in object oriented language (C++) that includes the mathematical engine of several physical processes, which are suitable to be employed in the transport of practically all types of particles and heavy ions. GEANT4 has also several tools to define materials, geometry, sources of radiation, beams of particles, electromagnetic fields, and graphical visualization of the experimental setup. After a brief description of the GEANT4 toolkit, this presentation reports investigations carried out by our group that involve simulations in the areas of dosimetry, nuclear instrumentation and medical physics. The physical processes available for photons, electrons, positrons and heavy ions were used in these simulations.

  3. Software design by reusing architectures

    NASA Technical Reports Server (NTRS)

    Bhansali, Sanjay; Nii, H. Penny

    1992-01-01

    Abstraction fosters reuse by providing a class of artifacts that can be instantiated or customized to produce a set of artifacts meeting different specific requirements. It is proposed that significant leverage can be obtained by abstracting software system designs and the design process. The result of such an abstraction is a generic architecture and a set of knowledge-based, customization tools that can be used to instantiate the generic architecture. An approach for designing software systems based on the above idea are described. The approach is illustrated through an implemented example, and the advantages and limitations of the approach are discussed.

  4. Shuttle mission simulator software conceptual design

    NASA Technical Reports Server (NTRS)

    Burke, J. F.

    1973-01-01

    Software conceptual designs (SCD) are presented for meeting the simulator requirements for the shuttle missions. The major areas of the SCD discussed include: malfunction insertion, flight software, applications software, systems software, and computer complex.

  5. The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

    NASA Astrophysics Data System (ADS)

    Piotrowski, Lech Wiktor; Casolino, Marco; Ebisuzaki, Toshikazu; Higashide, Kazuhiro

    2015-02-01

    Recent incident in the Fukushima power plant caused a growing concern about the radiation contamination and resulted in lowering the Japanese limits for the permitted amount of 137Cs in food to 100 Bq/kg. To increase safety and ease the concern we are developing LANFOS (Large Food Non-destructive Area Sampler)-a compact, easy to use detector for assessment of radiation in food. Described in this paper LANFOS-H has a 4 π coverage to assess the amount of 137Cs present, separating it from the possible 40K food contamination. Therefore, food samples do not have to be pre-processed prior to a test and can be consumed after measurements. It is designed for use by non-professionals in homes and small institutions such as schools, showing safety of the samples, but can be also utilized by specialists providing radiation spectrum. Proper assessment of radiation in food in the apparatus requires estimation of the γ conversion factor of the detectors-how many γ photons will produce a signal. In this paper we show results of the Monte Carlo estimation of this factor for various approximated shapes of fish, vegetables and amounts of rice, performed with Geant4 package. We find that the conversion factor combined from all the detectors is similar for all food types and is around 37%, varying maximally by 5% with sample length, much less than for individual detectors. The different inclinations and positions of samples in the detector introduce uncertainty of 1.4%. This small uncertainty validates the concept of a 4 π non-destructive apparatus.

  6. The GEANT4 toolkit capability in the hadron therapy field: simulation of a transport beam line

    NASA Astrophysics Data System (ADS)

    Cirrone, G. A. P.; Cuttone, G.; Di Rosa, F.; Raffaele, L.; Russo, G.; Guatelli, S.; Pia, M. G.

    2006-01-01

    At Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare of Catania (Sicily, Italy), the first Italian hadron therapy facility named CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been realized. Inside CATANA 62 MeV proton beams, accelerated by a superconducting cyclotron, are used for the radiotherapeutic treatments of some types of ocular tumours. Therapy with hadron beams still represents a pioneer technique, and only a few centers worldwide can provide this advanced specialized cancer treatment. On the basis of the experience so far gained, and considering the future hadron-therapy facilities to be developed (Rinecker, Munich Germany, Heidelberg/GSI, Darmstadt, Germany, PSI Villigen, Switzerland, CNAO, Pavia, Italy, Centro di Adroterapia, Catania, Italy) we decided to develop a Monte Carlo application based on the GEANT4 toolkit, for the design, the realization and the optimization of a proton-therapy beam line. Another feature of our project is to provide a general tool able to study the interactions of hadrons with the human tissue and to test the analytical-based treatment planning systems actually used in the routine practice. All the typical elements of a hadron-therapy line, such as diffusers, range shifters, collimators and detectors were modelled. In particular, we simulated the Markus type ionization chamber and a Gaf Chromic film as dosimeters to reconstruct the depth (Bragg peak and Spread Out Bragg Peak) and lateral dose distributions, respectively. We validated our simulated detectors comparing the results with the experimental data available in our facility.

  7. Structural Analysis and Design Software

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Collier Research and Development Corporation received a one-of-a-kind computer code for designing exotic hypersonic aircraft called ST-SIZE in the first ever Langley Research Center software copyright license agreement. Collier transformed the NASA computer code into a commercial software package called HyperSizer, which integrates with other Finite Element Modeling and Finite Analysis private-sector structural analysis program. ST-SIZE was chiefly conceived as a means to improve and speed the structural design of a future aerospace plane for Langley Hypersonic Vehicles Office. Including the NASA computer code into HyperSizer has enabled the company to also apply the software to applications other than aerospace, including improved design and construction for offices, marine structures, cargo containers, commercial and military aircraft, rail cars, and a host of everyday consumer products.

  8. Software Design for Smile Analysis

    PubMed Central

    Sodagar, A.; Rafatjoo, R.; Gholami Borujeni, D.; Noroozi, H.; Sarkhosh, A.

    2010-01-01

    Introduction: Esthetics and attractiveness of the smile is one of the major demands in contemporary orthodontic treatment. In order to improve a smile design, it is necessary to record “posed smile” as an intentional, non-pressure, static, natural and reproducible smile. The record then should be analyzed to determine its characteristics. In this study, we intended to design and introduce a software to analyze the smile rapidly and precisely in order to produce an attractive smile for the patients. Materials and Methods: For this purpose, a practical study was performed to design multimedia software “Smile Analysis” which can receive patients’ photographs and videographs. After giving records to the software, the operator should mark the points and lines which are displayed on the system’s guide and also define the correct scale for each image. Thirty-three variables are measured by the software and displayed on the report page. Reliability of measurements in both image and video was significantly high (α=0.7–1). Results: In order to evaluate intra- operator and inter-operator reliability, five cases were selected randomly. Statistical analysis showed that calculations performed in smile analysis software were both valid and highly reliable (for both video and photo). Conclusion: The results obtained from smile analysis could be used in diagnosis, treatment planning and evaluation of the treatment progress. PMID:21998792

  9. Development of a Geant4 based Monte Carlo Algorithm to evaluate the MONACO VMAT treatment accuracy.

    PubMed

    Fleckenstein, Jens; Jahnke, Lennart; Lohr, Frank; Wenz, Frederik; Hesser, Jürgen

    2013-02-01

    A method to evaluate the dosimetric accuracy of volumetric modulated arc therapy (VMAT) treatment plans, generated with the MONACO™ (version 3.0) treatment planning system in realistic CT-data with an independent Geant4 based dose calculation algorithm is presented. Therefore a model of an Elekta Synergy linear accelerator treatment head with an MLCi2 multileaf collimator was implemented in Geant4. The time dependent linear accelerator components were modeled by importing either logfiles of an actual plan delivery or a DICOM-RT plan sequence. Absolute dose calibration, depending on a reference measurement, was applied. The MONACO as well as the Geant4 treatment head model was commissioned with lateral profiles and depth dose curves of square fields in water and with film measurements in inhomogeneous phantoms. A VMAT treatment plan for a patient with a thoracic tumor and a VMAT treatment plan of a patient, who received treatment in the thoracic spine region including metallic implants, were used for evaluation. MONACO, as well as Geant4, depth dose curves and lateral profiles of square fields had a mean local gamma (2%, 2mm) tolerance criteria agreement of more than 95% for all fields. Film measurements in inhomogeneous phantoms with a global gamma of (3%, 3mm) showed a pass rate above 95% in all voxels receiving more than 25% of the maximum dose. A dose-volume-histogram comparison of the VMAT patient treatment plans showed mean deviations between Geant4 and MONACO of -0.2% (first patient) and 2.0% (second patient) for the PTVs and (0.5±1.0)% and (1.4±1.1)% for the organs at risk in relation to the prescription dose. The presented method can be used to validate VMAT dose distributions generated by a large number of small segments in regions with high electron density gradients. The MONACO dose distributions showed good agreement with Geant4 and film measurements within the simulation and measurement errors. PMID:22921843

  10. Managing Software Design and Design Changes

    NASA Technical Reports Server (NTRS)

    Loesh, R. E.

    1985-01-01

    Microprocessor-based system for document production work scheduling, and change control and management information aids in design, development, and control of software. Main components Z80 microprocessor, floppydisk and hard-disk drives, and a character printer. System linked to large computer. Major software components are control program monitor (CP/M), text-editing and wordprocessing system, workbreakdown-schedule processor, and data-base management tool.

  11. FIB Microfabrication Software Design Considerations

    NASA Astrophysics Data System (ADS)

    Thompson, W.; Bowe, T.; Morlock, S.; Moskowitz, A.; Plourde, G.; Spaulding, G.; Scialdone, C.; Tsiang, E.

    1986-06-01

    Profit margins on high-volume ICs, such as the 256-K DRAM, are now inadequate. U.S. and foreign manufacturers cannot fully recover the ICs' engineering costs before a new round of product competition begins. Consequently, some semiconductor manufacturers are seeking less competitive designs with healthier, longer lasting profitability. These designs must be converted quickly from CAD to functional circuits in order for irofits to be realized. For ultrahigh performance devices, customized circuits, and rapid verification of design, FIB (focused ion beam) systems provide a viable alternative to the lengthy process of producing a large mask set. Early models of FI equipment did not require sophisticated software. However, as FIB technology approaches adolescence, it must be supported by software that gives the user a friendly system, the flexibility to design a wide variety of circuits, and good growth potential for tomorrow's ICs. Presented here is an overview of IBT's MicroFocus" 150 hardware, followed by descriptions of several MicroFocus software modules. Data preparation techniques from IBCAD formats to chip layout are compared to the more conventional lithographies. The MicroFocus 150 schemes for user interfacing, error logging, calibration, and subsystem control are given. The MicroFocus's pattern generator and bit slice software are explained. IBT's FIB patterning algorithms, which allow the fabrication of unique device types, are reviewed.

  12. Therapeutic dose simulation of a 6 MV Varian Linac photon beam using GEANT4

    NASA Astrophysics Data System (ADS)

    Salama, E.; Ali, A. S.; Khaled, N. E.; Radi, A.

    2015-10-01

    A developed program in C++ language using GEANT4 libraries was used to simulate the gantry of a 6 MV high energy photon linear accelerator (Linac). The head of a clinical linear accelerator based on the manufacturer's detailed information is simulated. More than 2× 109 primary electrons are used to create the phase space file. Evaluation of the percentage depth dose (PDD) and flatness symmetry (lateral dose profiles) in water phantom were performed. Comparisons between experimental and simulated data were carried out for three field sizes; 5 × 5, 10 × 10 and 15 × 15 cm2. A relatively good agreement appeared between computed and measured PDD. Electron contamination and spatial distribution for both photons and electrons in the simulated beam are evaluated. Moreover, the obtained lateral dose profiles at 15, 50, and 100 mm depth are compatible with the measured values. The obtained results concluded that, GEANT4 code is a promising applicable Monte Carlo program in radiotherapy applications.

  13. Mass attenuation coefficients of composite materials by Geant4, XCOM and experimental data: comparative study

    NASA Astrophysics Data System (ADS)

    Medhat, M. E.; Singh, V. P.

    2014-09-01

    The main goal of this present study is focused on testing the applicability of Geant4 electromagnetic models for studying mass attenuations coefficients for different types of composite materials at 59.5, 80, 356, 661.6, 1173.2 and 1332.5 keV photon energies. The simulated results of mass attenuation coefficients were compared with the experimental and theoretical XCOM data for the same samples and a good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma rays with the several energies in different materials. The modeling for photon interaction parameters was standard for any type of composite samples. The Geant4 code can be utilized for gamma ray attenuation coefficients for the sample at different energies, which may sometimes be impractical by experiment investigation.

  14. Calculation of Coincidence Summing Correction Factors for an HPGe detector using GEANT4.

    PubMed

    Giubrone, G; Ortiz, J; Gallardo, S; Martorell, S; Bas, M C

    2016-07-01

    The aim of this paper was to calculate the True Coincidence Summing Correction Factors (TSCFs) for an HPGe coaxial detector in order to correct the summing effect as a result of the presence of (88)Y and (60)Co in a multigamma source used to obtain a calibration efficiency curve. Results were obtained for three volumetric sources using the Monte Carlo toolkit, GEANT4. The first part of this paper deals with modeling the detector in order to obtain a simulated full energy peak efficiency curve. A quantitative comparison between the measured and simulated values was made across the entire energy range under study. The True Summing Correction Factors were calculated for (88)Y and (60)Co using the full peak efficiencies obtained with GEANT4. This methodology was subsequently applied to (134)Cs, and presented a complex decay scheme. PMID:27085040

  15. Estimation of photoneutron yield in linear accelerator with different collimation systems by Geant4 and MCNPX simulation codes.

    PubMed

    Kim, Yoon Sang; Khazaei, Zeinab; Ko, Junho; Afarideh, Hossein; Ghergherehchi, Mitra

    2016-04-01

    At present, the bremsstrahlung photon beams produced by linear accelerators are the most commonly employed method of radiotherapy for tumor treatments. A photoneutron source based on three different energies (6, 10 and 15 MeV) of a linac electron beam was designed by means of Geant4 and Monte Carlo N-Particle eXtended (MCNPX) simulation codes. To obtain maximum neutron yield, two arrangements for the photo neutron convertor were studied: (a) without a collimator, and (b) placement of the convertor after the collimator. The maximum photon intensities in tungsten were 0.73, 1.24 and 2.07 photon/e at 6, 10 and 15 MeV, respectively. There was no considerable increase in the photon fluence spectra from 6 to 15 MeV at the optimum thickness between 0.8 mm and 2 mm of tungsten. The optimum dimensions of the collimator were determined to be a length of 140 mm with an aperture of 5 mm  ×  70 mm for iron in a slit shape. According to the neutron yield, the best thickness obtained for the studied materials was 30 mm. The number of neutrons generated in BeO achieved the maximum value at 6 MeV, unlike that in Be, where the highest number of neutrons was observed at 15 MeV. Statistical uncertainty in all simulations was less than 0.3% and 0.05% for MCNPX and the standard electromagnetic (EM) physics packages of Geant4, respectively. Differences among spectra in various regions are due to various cross-section and stopping power data and different simulations of the physics processes. PMID:26975304

  16. Estimation of photoneutron yield in linear accelerator with different collimation systems by Geant4 and MCNPX simulation codes

    NASA Astrophysics Data System (ADS)

    Kim, Yoon Sang; Khazaei, Zeinab; Ko, Junho; Afarideh, Hossein; Ghergherehchi, Mitra

    2016-04-01

    At present, the bremsstrahlung photon beams produced by linear accelerators are the most commonly employed method of radiotherapy for tumor treatments. A photoneutron source based on three different energies (6, 10 and 15 MeV) of a linac electron beam was designed by means of Geant4 and Monte Carlo N-Particle eXtended (MCNPX) simulation codes. To obtain maximum neutron yield, two arrangements for the photo neutron convertor were studied: (a) without a collimator, and (b) placement of the convertor after the collimator. The maximum photon intensities in tungsten were 0.73, 1.24 and 2.07 photon/e at 6, 10 and 15 MeV, respectively. There was no considerable increase in the photon fluence spectra from 6 to 15 MeV at the optimum thickness between 0.8 mm and 2 mm of tungsten. The optimum dimensions of the collimator were determined to be a length of 140 mm with an aperture of 5 mm  ×  70 mm for iron in a slit shape. According to the neutron yield, the best thickness obtained for the studied materials was 30 mm. The number of neutrons generated in BeO achieved the maximum value at 6 MeV, unlike that in Be, where the highest number of neutrons was observed at 15 MeV. Statistical uncertainty in all simulations was less than 0.3% and 0.05% for MCNPX and the standard electromagnetic (EM) physics packages of Geant4, respectively. Differences among spectra in various regions are due to various cross-section and stopping power data and different simulations of the physics processes.

  17. Calculation of self-shielding factor for neutron activation experiments using GEANT4 and MCNP

    NASA Astrophysics Data System (ADS)

    Romero-Barrientos, Jaime; Molina, F.; Aguilera, Pablo; Arellano, H. F.

    2016-07-01

    The neutron self-shielding factor G as a function of the neutron energy was obtained for 14 pure metallic samples in 1000 isolethargic energy bins from 1.10-5eV to 2.107eV using Monte Carlo simulations in GEANT4 and MCNP6. The comparison of these two Monte Carlo codes shows small differences in the final self-shielding factor mostly due to the different cross section databases that each program uses.

  18. R&D on co-working transport schemes in Geant4

    NASA Astrophysics Data System (ADS)

    Pia, M. G.; Saracco, P.; Sudhakar, M.; Zoglauer, A.; Augelli, M.; Gargioni, E.; Kim, C. H.; Quintieri, L.; de Queiroz Filho, P. P.; de Souza Santos, D.; Weidenspointner, G.; Begalli, M.

    2010-04-01

    A research and development (R&D) project related to the extension of the Geant4 toolkit has been recently launched to address fundamental methods in radiation transport simulation. The project focuses on simulation at different scales in the same experimental environment; this problem requires new methods across the current boundaries of condensed-random-walk and discrete transport schemes. The new developments have been motivated by experimental requirements in various domains, including nanodosimetry, astronomy and detector developments for high energy physics applications.

  19. Application of TDCR-Geant4 modeling to standardization of 63Ni.

    PubMed

    Thiam, C; Bobin, C; Chauvenet, B; Bouchard, J

    2012-09-01

    As an alternative to the classical TDCR model applied to liquid scintillation (LS) counting, a stochastic approach based on the Geant4 toolkit is presented for the simulation of light emission inside the dedicated three-photomultiplier detection system. To this end, the Geant4 modeling includes a comprehensive description of optical properties associated with each material constituting the optical chamber. The objective is to simulate the propagation of optical photons from their creation in the LS cocktail to the production of photoelectrons in the photomultipliers. First validated for the case of radionuclide standardization based on Cerenkov emission, the scintillation process has been added to a TDCR-Geant4 modeling using the Birks expression in order to account for the light-emission nonlinearity owing to ionization quenching. The scintillation yield of the commercial Ultima Gold LS cocktail has been determined from double-coincidence detection efficiencies obtained for (60)Co and (54)Mn with the 4π(LS)β-γ coincidence method. In this paper, the stochastic TDCR modeling is applied for the case of the standardization of (63)Ni (pure β(-)-emitter; E(max)=66.98 keV) and the activity concentration is compared with the result given by the classical model. PMID:22436447

  20. Comparison of dose distributions for Hounsfield number conversion methods in GEANT4

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Dong; Kim, Byung Yong; Kim, Eng Chan; Yun, Sang Mo; Kang, Jeong Ku; Kim, Sung Kyu

    2014-06-01

    The conversion of patient computed tomography (CT) data to voxel phantoms is essential for CT-based Monte Carlo (MC) dose calculations, and incorrect assignments of materials and mass densities can lead to large errors in dose distributions. We investigated the effects of mass density and material assignments on GEANT4-based photon dose calculations. Three material conversion methods and four density conversion methods were compared for a lung tumor case. The dose calculations for 6-MV photon beams with a field size of 10 × 10 cm2 were performed using a 0.5 × 0.5 × 0.5 cm3 voxel with 1.2 × 109 histories. The material conversion methods led to different material assignment percentages in converted voxel regions. The GEANT4 example and the modified Schneider material conversion methods showed large local dose differences relative to the BEAMnrc default method for lung and other tissues. For mass density conversion methods when only water was used, our results showed only slight dose differences. Gaussian-like distributions, with mean values close to zero, were obtained when the reference method was compared with the other methods. The maximum dose difference of ˜2% indicated that the dose distributions agreed relatively well. Material assignment methods probably have more significant impacts on dose distributions than mass density assignment methods. The study confirms that material assignment methods cause significant dose differences in GEANT4-based photon dose calculations.

  1. Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring.

    PubMed

    Pinto, Marco; Dauvergne, Denis; Freud, Nicolas; Krimmer, Jochen; Létang, Jean M; Testa, Etienne

    2016-01-01

    Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm(2). PMID:26858937

  2. Monte Carlo modeling and validation of a proton treatment nozzle by using the Geant4 toolkit

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Hyun; Kang, Young Nam; Suh, Tae-Suk; Shin, Jungwook; Kim, Jong Won; Yoo, Seung Hoon; Park, Seyjoon; Lee, Sang Hoon; Cho, Sungkoo; Shin, Dongho; Kim, Dae Yong; Lee, Se Byeong

    2012-10-01

    Modern commercial treatment planning systems for proton therapy use the pencil beam algorithm for calculating the absorbed dose. Although it is acceptable for clinical radiation treatment, the accuracy of this method is limited. Alternatively, the Monte Carlo method, which is relatively accurate in dose calculations, has been applied recently to proton therapy. To reduce the remaining uncertainty in proton therapy dose calculations, in the present study, we employed Monte Carlo simulations and the Geant4 simulation toolkit to develop a model for a of a proton treatment nozzle. The results from a Geant4-based medical application of the proton treatment nozzle were compared to the measured data. Simulations of the percentage depth dose profiles showed very good agreement within 1 mm in distal range and 3 mm in modulated width. Moreover, the lateral dose profiles showed good agreement within 3% in the central region of the field and within 10% in the penumbra regions. In this work, we proved that the Geant4 Monte Carlo model of a proton treatment nozzle could be used to the calculate proton dose distributions accurately.

  3. Comparison of GEANT4 Simulations with Experimental Data for Thick Al Absorbers

    NASA Astrophysics Data System (ADS)

    Yevseyeva, Olga; de Assis, Joaquim; Evseev, Ivan; Schelin, Hugo; Paschuk, Sergei; Milhoretto, Edney; Setti, João; Díaz, Katherin; Hormaza, Joel; Lopes, Ricardo

    2009-06-01

    Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Therefore, relatively small differences in the total proton stopping power given, for example, by the different models provided by GEANT4 can lead to significant disagreements in the final proton energy spectra when integrated along lengthy proton trajectories. This work presents proton energy spectra obtained by GEANT4.8.2 simulations using ICRU49, Ziegler1985 and Ziegler2000 models for 19.68 MeV protons passing through a number of Al absorbers with various thicknesses. The spectra were compared with the experimental data, with TRIM/SRIM2008 and MCNPX2.4.0 simulations, and with the Payne analytical solution for the transport equation in the Fokker-Plank approximation. It is shown that the MCNPX simulations reasonably reproduce well all experimental spectra. For the relatively thin targets all the methods give practically identical results but this is not the same for the thick absorbers. It should be noted that all the spectra were measured at the proton energies significantly above 2 MeV, i.e., in the so-called "Bethe-Bloch region". Therefore the observed disagreements in GEANT4 results, simulated with different models, are somewhat unexpected. Further studies are necessary for better understanding and definitive conclusions.

  4. Modeling proton and alpha elastic scattering in liquid water in Geant4-DNA

    NASA Astrophysics Data System (ADS)

    Tran, H. N.; El Bitar, Z.; Champion, C.; Karamitros, M.; Bernal, M. A.; Francis, Z.; Ivantchenko, V.; Lee, S. B.; Shin, J. I.; Incerti, S.

    2015-01-01

    Elastic scattering of protons and alpha (α) particles by water molecules cannot be neglected at low incident energies. However, this physical process is currently not available in the "Geant4-DNA" extension of the Geant4 Monte Carlo simulation toolkit. In this work, we report on theoretical differential and integral cross sections of the elastic scattering process for 100 eV-1 MeV incident protons and for 100 eV-10 MeV incident α particles in liquid water. The calculations are performed within the classical framework described by Everhart et al., Ziegler et al. and by the ICRU 49 Report. Then, we propose an implementation of the corresponding classes into the Geant4-DNA toolkit for modeling the elastic scattering of protons and α particles. Stopping powers as well as ranges are also reported. Then, it clearly appears that the account of the elastic scattering process in the slowing-down of the charged particle improves the agreement with the existing data in particular with the ICRU recommendations.

  5. Optical simulation of monolithic scintillator detectors using GATE/GEANT4.

    PubMed

    van der Laan, D J Jan; Schaart, Dennis R; Maas, Marnix C; Beekman, Freek J; Bruyndonckx, Peter; van Eijk, Carel W E

    2010-03-21

    Much research is being conducted on position-sensitive scintillation detectors for medical imaging, particularly for emission tomography. Monte Carlo simulations play an essential role in many of these research activities. As the scintillation process, the transport of scintillation photons through the crystal(s), and the conversion of these photons into electronic signals each have a major influence on the detector performance; all of these processes may need to be incorporated in the model to obtain accurate results. In this work the optical and scintillation models of the GEANT4 simulation toolkit are validated by comparing simulations and measurements on monolithic scintillator detectors for high-resolution positron emission tomography (PET). We have furthermore made the GEANT4 optical models available within the user-friendly GATE simulation platform (as of version 3.0). It is shown how the necessary optical input parameters can be determined with sufficient accuracy. The results show that the optical physics models of GATE/GEANT4 enable accurate prediction of the spatial and energy resolution of monolithic scintillator PET detectors. PMID:20182005

  6. GEANT4 simulations of the n_TOF spallation source and their benchmarking

    NASA Astrophysics Data System (ADS)

    Lo Meo, S.; Cortés-Giraldo, M. A.; Massimi, C.; Lerendegui-Marco, J.; Barbagallo, M.; Colonna, N.; Guerrero, C.; Mancusi, D.; Mingrone, F.; Quesada, J. M.; Sabate-Gilarte, M.; Vannini, G.; Vlachoudis, V.

    2015-12-01

    Neutron production and transport in the spallation target of the n_TOF facility at CERN has been simulated with GEANT4. The results obtained with different models of high-energy nucleon-nucleus interaction have been compared with the measured characteristics of the neutron beam, in particular the flux and its dependence on neutron energy, measured in the first experimental area. The best agreement at present, within 20% for the absolute value of the flux, and within few percent for the energy dependence in the whole energy range from thermal to 1 GeV, is obtained with the INCL++ model coupled with the GEANT4 native de-excitation model. All other available models overestimate by a larger factor, of up to 70%, the n_TOF neutron flux. The simulations are also able to accurately reproduce the neutron beam energy resolution function, which is essentially determined by the moderation time inside the target/moderator assembly. The results here reported provide confidence on the use of GEANT4 for simulations of spallation neutron sources.

  7. Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring

    PubMed Central

    Pinto, Marco; Dauvergne, Denis; Freud, Nicolas; Krimmer, Jochen; Létang, Jean M.; Testa, Etienne

    2016-01-01

    Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm2. PMID:26858937

  8. Software Performs Complex Design Analysis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Designers use computational fluid dynamics (CFD) to gain greater understanding of the fluid flow phenomena involved in components being designed. They also use finite element analysis (FEA) as a tool to help gain greater understanding of the structural response of components to loads, stresses and strains, and the prediction of failure modes. Automated CFD and FEA engineering design has centered on shape optimization, which has been hindered by two major problems: 1) inadequate shape parameterization algorithms, and 2) inadequate algorithms for CFD and FEA grid modification. Working with software engineers at Stennis Space Center, a NASA commercial partner, Optimal Solutions Software LLC, was able to utilize its revolutionary, one-of-a-kind arbitrary shape deformation (ASD) capability-a major advancement in solving these two aforementioned problems-to optimize the shapes of complex pipe components that transport highly sensitive fluids. The ASD technology solves the problem of inadequate shape parameterization algorithms by allowing the CFD designers to freely create their own shape parameters, therefore eliminating the restriction of only being able to use the computer-aided design (CAD) parameters. The problem of inadequate algorithms for CFD grid modification is solved by the fact that the new software performs a smooth volumetric deformation. This eliminates the extremely costly process of having to remesh the grid for every shape change desired. The program can perform a design change in a markedly reduced amount of time, a process that would traditionally involve the designer returning to the CAD model to reshape and then remesh the shapes, something that has been known to take hours, days-even weeks or months-depending upon the size of the model.

  9. Model-based software design

    NASA Technical Reports Server (NTRS)

    Iscoe, Neil; Liu, Zheng-Yang; Feng, Guohui; Yenne, Britt; Vansickle, Larry; Ballantyne, Michael

    1992-01-01

    Domain-specific knowledge is required to create specifications, generate code, and understand existing systems. Our approach to automating software design is based on instantiating an application domain model with industry-specific knowledge and then using that model to achieve the operational goals of specification elicitation and verification, reverse engineering, and code generation. Although many different specification models can be created from any particular domain model, each specification model is consistent and correct with respect to the domain model.

  10. MaGe - a GEANT4-based Monte Carlo Application Framework for Low-background Germanium Experiments

    SciTech Connect

    Boswell, M.; Chan, Yuen-Dat; Detwiler, Jason A.; Finnerty, P.; Henning, R.; Gehman, Victor; Johnson, Robert A.; Jordan, David V.; Kazkaz, Kareem; Knapp, Markus; Kroninger, Kevin; Lenz, Daniel; Leviner, L.; Liu, Jing; Liu, Xiang; MacMullin, S.; Marino, Michael G.; Mokhtarani, A.; Pandola, Luciano; Schubert, Alexis G.; Schubert, J.; Tomei, Claudia; Volynets, Oleksandr

    2011-06-13

    We describe a physics simulation software framework, MAGE, that is based on the GEANT4 simulation toolkit. MAGE is used to simulate the response of ultra-low radioactive background radiation detectors to ionizing radiation, specifically the MAJ ORANA and GE RDA neutrinoless double-beta decay experiments. MAJ ORANA and GERDA use high-purity germanium technology to search for the neutrinoless double-beta decay of the 76 Ge isotope, and MAGE is jointly developed between these two collaborations. The MAGE framework contains simulated geometries of common objects, prototypes, test stands, and the actual experiments. It also implements customized event generators, GE ANT 4 physics lists, and output formats. All of these features are available as class libraries that are typically compiled into a single executable. The user selects the particular experimental setup implementation at run-time via macros. The combination of all these common classes into one framework reduces duplication of efforts, eases comparison between simulated data and experiment, and simplifies the addition of new detectors to be simulated. This paper focuses on the software framework, custom event generators, and physics list.

  11. GEANT4 calculations of neutron dose in radiation protection using a homogeneous phantom and a Chinese hybrid male phantom.

    PubMed

    Geng, Changran; Tang, Xiaobin; Guan, Fada; Johns, Jesse; Vasudevan, Latha; Gong, Chunhui; Shu, Diyun; Chen, Da

    2016-03-01

    The purpose of this study is to verify the feasibility of applying GEANT4 (version 10.01) in neutron dose calculations in radiation protection by comparing the calculation results with MCNP5. The depth dose distributions are investigated in a homogeneous phantom, and the fluence-to-dose conversion coefficients are calculated for different organs in the Chinese hybrid male phantom for neutrons with energy ranging from 1 × 10(-9) to 10 MeV. By comparing the simulation results between GEANT4 and MCNP5, it is shown that using the high-precision (HP) neutron physics list, GEANT4 produces the closest simulation results to MCNP5. However, differences could be observed when the neutron energy is lower than 1 × 10(-6) MeV. Activating the thermal scattering with an S matrix correction in GEANT4 with HP and MCNP5 in thermal energy range can reduce the difference between these two codes. PMID:26156875

  12. Automating software design system DESTA

    NASA Technical Reports Server (NTRS)

    Lovitsky, Vladimir A.; Pearce, Patricia D.

    1992-01-01

    'DESTA' is the acronym for the Dialogue Evolutionary Synthesizer of Turnkey Algorithms by means of a natural language (Russian or English) functional specification of algorithms or software being developed. DESTA represents the computer-aided and/or automatic artificial intelligence 'forgiving' system which provides users with software tools support for algorithm and/or structured program development. The DESTA system is intended to provide support for the higher levels and earlier stages of engineering design of software in contrast to conventional Computer Aided Design (CAD) systems which provide low level tools for use at a stage when the major planning and structuring decisions have already been taken. DESTA is a knowledge-intensive system. The main features of the knowledge are procedures, functions, modules, operating system commands, batch files, their natural language specifications, and their interlinks. The specific domain for the DESTA system is a high level programming language like Turbo Pascal 6.0. The DESTA system is operational and runs on an IBM PC computer.

  13. Monte Carlo calculations of thermal neutron capture in gadolinium: a comparison of GEANT4 and MCNP with measurements.

    PubMed

    Enger, Shirin A; Munck af Rosenschöld, Per; Rezaei, Arash; Lundqvist, Hans

    2006-02-01

    GEANT4 is a Monte Carlo code originally implemented for high-energy physics applications and is well known for particle transport at high energies. The capacity of GEANT4 to simulate neutron transport in the thermal energy region is not equally well known. The aim of this article is to compare MCNP, a code commonly used in low energy neutron transport calculations and GEANT4 with experimental results and select the suitable code for gadolinium neutron capture applications. To account for the thermal neutron scattering from chemically bound atoms [S(alpha,beta)] in biological materials a comparison of thermal neutron fluence in tissue-like poly(methylmethacrylate) phantom is made with MCNP4B, GEANT4 6.0 patch1, and measurements from the neutron capture therapy (NCT) facility at the Studsvik, Sweden. The fluence measurements agreed with MCNP calculated results considering S(alpha,beta). The location of the thermal neutron peak calculated with MCNP without S(alpha,beta) and GEANT4 is shifted by about 0.5 cm towards a shallower depth and is 25%-30% lower in amplitude. Dose distribution from the gadolinium neutron capture reaction is then simulated by MCNP and compared with measured data. The simulations made by MCNP agree well with experimental results. As long as thermal neutron scattering from chemically bound atoms are not included in GEANT4 it is not suitable for NCT applications. PMID:16532938

  14. Monte Carlo calculations of thermal neutron capture in gadolinium: A comparison of GEANT4 and MCNP with measurements

    SciTech Connect

    Enger, Shirin A.; Munck af Rosenschoeld, Per; Rezaei, Arash; Lundqvist, Hans

    2006-02-15

    GEANT4 is a Monte Carlo code originally implemented for high-energy physics applications and is well known for particle transport at high energies. The capacity of GEANT4 to simulate neutron transport in the thermal energy region is not equally well known. The aim of this article is to compare MCNP, a code commonly used in low energy neutron transport calculations and GEANT4 with experimental results and select the suitable code for gadolinium neutron capture applications. To account for the thermal neutron scattering from chemically bound atoms [S({alpha},{beta})] in biological materials a comparison of thermal neutron fluence in tissue-like poly(methylmethacrylate) phantom is made with MCNP4B, GEANT4 6.0 patch1, and measurements from the neutron capture therapy (NCT) facility at the Studsvik, Sweden. The fluence measurements agreed with MCNP calculated results considering S({alpha},{beta}). The location of the thermal neutron peak calculated with MCNP without S({alpha},{beta}) and GEANT4 is shifted by about 0.5 cm towards a shallower depth and is 25%-30% lower in amplitude. Dose distribution from the gadolinium neutron capture reaction is then simulated by MCNP and compared with measured data. The simulations made by MCNP agree well with experimental results. As long as thermal neutron scattering from chemically bound atoms are not included in GEANT4 it is not suitable for NCT applications.

  15. Software engineering and Ada in design

    NASA Technical Reports Server (NTRS)

    Oneill, Don

    1986-01-01

    Modern software engineering promises significant reductions in software costs and improvements in software quality. The Ada language is the focus for these software methodology and tool improvements. The IBM FSD approach, including the software engineering practices that guide the systematic design and development of software products and the management of the software process are examined. The revised Ada design language adaptation is revealed. This four level design methodology is detailed including the purpose of each level, the management strategy that integrates the software design activity with the program milestones, and the technical strategy that maps the Ada constructs to each level of design. A complete description of each design level is provided along with specific design language recording guidelines for each level. Finally, some testimony is offered on education, tools, architecture, and metrics resulting from project use of the four level Ada design language adaptation.

  16. A GEANT4 Monte Carlo simulation to describe the time response of a coupled SiPM and LYSO detection system

    NASA Astrophysics Data System (ADS)

    Leming, E.; De Santo, A.; Salvatore, F.; Camanzi, B.; Lohstroh, A.

    2014-06-01

    In recent years the silicon photomultiplier has been investigated as an alternative to the traditional photomultiplier tube in a range of applications, including Time-of-flight Positron Emission Tomography (TOF-PET). In this paper we discuss a GEANT4 simulation framework, which has been developed to drive the design of a scalable TOF-PET apparatus to be built at the Rutherford Appleton Laboratory, UK. First results presented in this paper simulate the response of an Hamamatsu Multi-Pixel Photon Counter (S10362-33-050c) coupled to LYSO scintillating crystals, with focus on the timing response of coincidence signals.

  17. Validation of recent Geant4 physics models for application in carbon ion therapy

    NASA Astrophysics Data System (ADS)

    Lechner, A.; Ivanchenko, V. N.; Knobloch, J.

    2010-07-01

    Cancer treatment with energetic carbon ions has distinct advantages over proton or photon irradiation. In this paper we present a simulation model integrated into the Geant4 Monte Carlo toolkit (version 9.3) which enables the use of ICRU 73 stopping powers for ion transport calculations. For a few materials, revised ICRU 73 stopping power tables recently published by ICRU (P. Sigmund, A. Schinner, H. Paul, Errata and Addenda: ICRU Report 73 (Stopping of Ions Heavier than Helium), International Commission on Radiation Units and Measurements, 2009) were incorporated into Geant4, also covering media like water which are of importance in radiotherapeutical applications. We examine, with particular attention paid to the recent developments, the accuracy of current Geant4 models for simulating Bragg peak profiles of 12C ions incident on water and polyethylene targets. Simulated dose distributions are validated against experimental data available in the literature, where the focus is on beam energies relevant to ion therapy applications (90-400 MeV/u). A quantitative analysis is performed which addresses the precision of the Bragg peak position and proportional features of the dose distribution. It is shown that experimental peak positions can be reproduced within 0.2% of the particle range in the case of water, and within 0.9% in the case of polyethylene. The comparisons also demonstrate that the simulations accurately render the full width at half maximum (FWHM) of the measured Bragg peaks in water. For polyethylene slight deviations from experimental peak widths are partly attributed to systematic effects due to a simplified geometry model adopted in the simulation setup.

  18. Validation of the GEANT4 simulation of bremsstrahlung from thick targets below 3 MeV

    NASA Astrophysics Data System (ADS)

    Pandola, L.; Andenna, C.; Caccia, B.

    2015-05-01

    The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the GEANT4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. The energy spectra for the different configurations of emission angles, energies and targets are considered. Simulations are performed by using the three alternative sets of electromagnetic models that are available in GEANT4 to describe bremsstrahlung. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, GEANT4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10-30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models over-estimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically under-estimate the total photon yield, providing agreement between 10% and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.

  19. Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN

    PubMed Central

    Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

    2015-01-01

    After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists. PMID:26170558

  20. Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

    PubMed

    Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

    2015-01-01

    After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists. PMID:26170558

  1. GEANT4 simulation of the effects of Doppler energy broadening in Compton imaging.

    PubMed

    Uche, C Z; Cree, M J; Round, W H

    2011-09-01

    A Monte Carlo approach was used to study the effects of Doppler energy broadening on Compton camera performance. The GEANT4 simulation toolkit was used to model the radiation transport and interactions with matter in a simulated Compton camera. The low energy electromagnetic physics model of GEANT4 incorporating Doppler broadening developed by Longo et al. was used in the simulations. The camera had a 9 × 9 cm scatterer and a 10 × 10 cm absorber with a scatterer to-absorber separation of 5 cm. Modelling was done such that only the effects of Doppler broadening were taken into consideration and effects of scatterer and absorber thickness and pixelation were not taken into account, thus a 'perfect' Compton camera was assumed. Scatterer materials were either silicon or germanium and the absorber material was cadmium zinc telluride. Simulations were done for point sources 10 cm in front of the scatterer. The results of the simulations validated the use of the low energy model of GEANT4. As expected, Doppler broadening was found to degrade the Compton camera imaging resolution. For a 140.5 keV source the resulting full-width-at-half-maximum (FWHM) of the point source image without accounting for Doppler broadening and using a silicon scatterer was 0.58 mm. This degraded to 7.1 mm when Doppler broadening was introduced and degraded further to 12.3 mm when a germanium scatterer was used instead of silicon. But for a 511 keV source, the FWHM was better than for a 140 keV source. The FWHM improved to 2.4 mm for a silicon scatterer and 4.6 mm for a germanium scatterer. Our result for silicon at 140.5 keV is in very good agreement with that published by An et al. PMID:21556971

  2. Simulation of the 6 MV Elekta Synergy Platform linac photon beam using Geant4 Application for Tomographic Emission

    PubMed Central

    Didi, Samir; Moussa, Abdelilah; Yahya, Tayalati; Mustafa, Zerfaoui

    2015-01-01

    The present work validates the Geant4 Application for Tomographic Emission Monte Carlo software for the simulation of a 6 MV photon beam given by Elekta Synergy Platform medical linear accelerator treatment head. The simulation includes the major components of the linear accelerator (LINAC) with multi-leaf collimator and a homogeneous water phantom. Calculations were performed for the photon beam with several treatment field sizes ranging from 5 cm × 5 cm to 30 cm × 30 cm at 100 cm distance from the source. The simulation was successfully validated by comparison with experimental distributions. Good agreement between simulations and measurements was observed, with dose differences of about 0.02% and 2.5% for depth doses and lateral dose profiles, respectively. This agreement was also emphasized by the Kolmogorov–Smirnov goodness-of-fit test and by the gamma-index comparisons where more than 99% of the points for all simulations fulfill the quality assurance criteria of 2 mm/2%. PMID:26500399

  3. Space radiation analysis: Radiation effects and particle interaction outside the Earth's magnetosphere using GRAS and GEANT4

    NASA Astrophysics Data System (ADS)

    Martinez, Lisandro M.; Kingston, Jennifer

    2012-03-01

    In order to explore the Moon and Mars it is necessary to investigate the hazards due to the space environment and especially ionizing radiation. According to previous papers, much information has been presented in radiation analysis inside the Earth's magnetosphere, but much of this work was not directly relevant to the interplanetary medium. This work intends to explore the effect of radiation on humans inside structures such as the ISS and provide a detailed analysis of galactic cosmic rays (GCRs) and solar proton events (SPEs) using SPENVIS (Space Environment Effects and Information System) and CREME96 data files for particle flux outside the Earth's magnetosphere. The simulation was conducted using GRAS, a European Space Agency (ESA) software based on GEANT4. Dose and equivalent dose have been calculated as well as secondary particle effects and GCR energy spectrum. The calculated total dose effects and equivalent dose indicate the risk and effects that space radiation could have on the crew, these values are calculated using two different types of structures, the ISS and the TransHab modules. Final results indicate the amounts of radiation expected to be absorbed by the astronauts during long duration interplanetary flights; this denotes importance of radiation shielding and the use of proper materials to reduce the effects.

  4. Simulation of the 6 MV Elekta Synergy Platform linac photon beam using Geant4 Application for Tomographic Emission.

    PubMed

    Didi, Samir; Moussa, Abdelilah; Yahya, Tayalati; Mustafa, Zerfaoui

    2015-01-01

    The present work validates the Geant4 Application for Tomographic Emission Monte Carlo software for the simulation of a 6 MV photon beam given by Elekta Synergy Platform medical linear accelerator treatment head. The simulation includes the major components of the linear accelerator (LINAC) with multi-leaf collimator and a homogeneous water phantom. Calculations were performed for the photon beam with several treatment field sizes ranging from 5 cm × 5 cm to 30 cm × 30 cm at 100 cm distance from the source. The simulation was successfully validated by comparison with experimental distributions. Good agreement between simulations and measurements was observed, with dose differences of about 0.02% and 2.5% for depth doses and lateral dose profiles, respectively. This agreement was also emphasized by the Kolmogorov-Smirnov goodness-of-fit test and by the gamma-index comparisons where more than 99% of the points for all simulations fulfill the quality assurance criteria of 2 mm/2%. PMID:26500399

  5. GEANT4 simulation of cyclotron radioisotope production in a solid target.

    PubMed

    Poignant, F; Penfold, S; Asp, J; Takhar, P; Jackson, P

    2016-05-01

    The use of radioisotopes in nuclear medicine is essential for diagnosing and treating cancer. The optimization of their production is a key factor in maximizing the production yield and minimizing the associated costs. An efficient approach to this problem is the use of Monte Carlo simulations prior to experimentation. By predicting isotopes yields, one can study the isotope of interest expected activity for different energy ranges. One can also study the target contamination with other radioisotopes, especially undesired radioisotopes of the wanted chemical element which are difficult to separate from the irradiated target and might result in increasing the dose when delivering the radiopharmaceutical product to the patient. The aim of this work is to build and validate a Monte Carlo simulation platform using the GEANT4 toolkit to model the solid target system of the South Australian Health and Medical Research Institute (SAHMRI) GE Healthcare PETtrace cyclotron. It includes a GEANT4 Graphical User Interface (GUI) where the user can modify simulation parameters such as the energy, shape and current of the proton beam, the target geometry and material, the foil geometry and material and the time of irradiation. The paper describes the simulation and presents a comparison of simulated and experimental/theoretical yields for various nuclear reactions on an enriched nickel 64 target using the GEANT4 physics model QGSP_BIC_AllHP, a model recently developed to evaluate with high precision the interaction of protons with energies below 200MeV available in Geant4 version 10.1. The simulation yield of the (64)Ni(p,n)(64)Cu reaction was found to be 7.67±0.074 mCi·μA(-1) for a target energy range of 9-12MeV. Szelecsenyi et al. (1993) gives a theoretical yield of 6.71mCi·μA(-1) and an experimental yield of 6.38mCi·μA(-1). The (64)Ni(p,n)(64)Cu cross section obtained with the simulation was also verified against the yield predicted from the nuclear database TENDL and

  6. Nuclear fragmentation reactions in extended media studied with Geant4 toolkit

    NASA Astrophysics Data System (ADS)

    Pshenichnov, Igor; Botvina, Alexander; Mishustin, Igor; Greiner, Walter

    2010-03-01

    It is well-known from numerous experiments that nuclear multifragmentation is a dominating mechanism for production of intermediate mass fragments in nucleus-nucleus collisions at energies above 100A MeV. In this paper we investigate the validity and performance of the Fermi break-up model and the statistical multifragmentation model implemented as parts of the Geant4 toolkit. We study the impact of violent nuclear disintegration reactions on the depth-dose profiles and yields of secondary fragments for beams of light and medium-weight nuclei propagating in extended media. Implications for ion-beam cancer therapy and shielding from cosmic radiation are discussed.

  7. Geant4 simulations on Compton scattering of laser photons on relativistic electrons

    SciTech Connect

    Filipescu, D.; Utsunomiya, H.; Gheorghe, I.; Glodariu, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Using Geant4, a complex simulation code of the interaction between laser photons and relativistic electrons was developed. We implemented physically constrained electron beam emittance and spacial distribution parameters and we also considered a Gaussian laser beam. The code was tested against experimental data produced at the γ-ray beam line GACKO (Gamma Collaboration Hutch of Konan University) of the synchrotron radiation facility NewSUBARU. Here we will discuss the implications of transverse missallignments of the collimation system relative to the electron beam axis.

  8. Integration of the low-energy particle track simulation code in Geant4

    NASA Astrophysics Data System (ADS)

    Arce, Pedro; Muñoz, Antonio; Moraleda, Montserrat; Gomez Ros, José María; Blanco, Fernando; Perez, José Manuel; García, Gustavo

    2015-08-01

    The Low-Energy Particle Track Simulation code (LEPTS) is a Monte Carlo code developed to simulate the damage caused by radiation at molecular level. The code is based on experimental data of scattering cross sections, both differential and integral, and energy loss data, complemented with theoretical calculations. It covers the interactions of electrons and positrons from energies of 10 keV down to 0.1 eV in different biologically relevant materials. In this article we briefly mention the main characteristics of this code and we present its integration within the Geant4 Monte Carlo toolkit.

  9. Application of Geant4 simulation for analysis of soil carbon inelastic neutron scattering measurements.

    PubMed

    Yakubova, Galina; Kavetskiy, Aleksandr; Prior, Stephen A; Torbert, H Allen

    2016-07-01

    Inelastic neutron scattering (INS) was applied to determine soil carbon content. Due to non-uniform soil carbon depth distribution, the correlation between INS signals with some soil carbon content parameter is not obvious; however, a proportionality between INS signals and average carbon weight percent in ~10cm layer for any carbon depth profile is demonstrated using Monte-Carlo simulation (Geant4). Comparison of INS and dry combustion measurements confirms this conclusion. Thus, INS measurements give the value of this soil carbon parameter. PMID:27124122

  10. FLOWTRAN-TF software design

    SciTech Connect

    Aleman, S.E.; Flach, G.P.; Hamm, L.L.; Lee, S.Y.; Smith, F.G. III.

    1993-02-01

    FLOWTRAN-TF was created to analyze an individual Mk22 fuel assembly during a large break Loss Of Coolant Accident (LOCA) scenario involving the Savannah River Site K-reactor after the initial few seconds of the transient. During the initial few seconds reactor cooling is limited by the static or Ledinegg flow instability phenomenon. The predecessor FLOWTRAN code was developed to analyze this portion of a LOCA. In the several seconds following the break, a significant fraction of the reactor coolant inventory leaks out the break, Emergency Cooling System (ECS) flow is initiated, and air enters the primary coolant circulation loops. Reactor fuel assemblies are cooled by a low flowrate air-water downflow. Existing commercial nuclear industry thermal-hydraulic codes were judged inadequate for detailed modeling of a Mk22 fuel assembly because the application involves a ribbed annular geometry, low pressure, downflow and an air-water mixture. FLOWTRAN-TF is a two-phase thermal-hydraulics code of similar technology to existing commercial codes such as RELAP and TRAC but customized for Savannah River Site applications. The main features and capabilities of FLOWTRAN-TF are detailed Mk22 fuel assembly ribbed annular geometry; conjugate heat transfer; detailed neutronic power distribution; three-dimensional heat conduction in Mk22 fuel and target tubes; two-dimensional coolant flow in channels (axial, azimuthal); single-phase and/or two-phase fluid (gas, liquid and/or gas-liquid); two-component (air, water); constitutive models applicable to low pressure air-water downflow in ribbed annular channels. The design of FLOWTRAN-TF is described in detail in this report which serves as the Software Design Report in accordance with Quality Assurance Procedure IV-4, Rev. 0 Software Design and Implementation'' in the 1Q34 manual.

  11. FLOWTRAN-TF software design

    SciTech Connect

    Aleman, S.E.; Flach, G.P.; Hamm, L.L.; Lee, S.Y.; Smith, F.G. III

    1993-02-01

    FLOWTRAN-TF was created to analyze an individual Mk22 fuel assembly during a large break Loss Of Coolant Accident (LOCA) scenario involving the Savannah River Site K-reactor after the initial few seconds of the transient. During the initial few seconds reactor cooling is limited by the static or Ledinegg flow instability phenomenon. The predecessor FLOWTRAN code was developed to analyze this portion of a LOCA. In the several seconds following the break, a significant fraction of the reactor coolant inventory leaks out the break, Emergency Cooling System (ECS) flow is initiated, and air enters the primary coolant circulation loops. Reactor fuel assemblies are cooled by a low flowrate air-water downflow. Existing commercial nuclear industry thermal-hydraulic codes were judged inadequate for detailed modeling of a Mk22 fuel assembly because the application involves a ribbed annular geometry, low pressure, downflow and an air-water mixture. FLOWTRAN-TF is a two-phase thermal-hydraulics code of similar technology to existing commercial codes such as RELAP and TRAC but customized for Savannah River Site applications. The main features and capabilities of FLOWTRAN-TF are detailed Mk22 fuel assembly ribbed annular geometry; conjugate heat transfer; detailed neutronic power distribution; three-dimensional heat conduction in Mk22 fuel and target tubes; two-dimensional coolant flow in channels (axial, azimuthal); single-phase and/or two-phase fluid (gas, liquid and/or gas-liquid); two-component (air, water); constitutive models applicable to low pressure air-water downflow in ribbed annular channels. The design of FLOWTRAN-TF is described in detail in this report which serves as the Software Design Report in accordance with Quality Assurance Procedure IV-4, Rev. 0 ``Software Design and Implementation`` in the 1Q34 manual.

  12. User interactive electric propulsion software design

    NASA Technical Reports Server (NTRS)

    Aston, Martha B.; Aston, Graeme; Brophy, John R.

    1989-01-01

    As electric propulsion technology matures from laboratory development to flight application, mission planners and spacecraft designers are increasingly required to determine the benefits and integration issues of using this propulsion capability. A computer software tool for supporting these analyses is presented. This tool combines detailed analytical models describing electric propulsion engine performance and subsystem design, and a software structure that is highly user interactive and adaptable. The software design methodology used to develop this software tool is presented in this paper.

  13. Software Design Improvements. Part 1; Software Benefits and Limitations

    NASA Technical Reports Server (NTRS)

    Lalli, Vincent R.; Packard, Michael H.; Ziemianski, Tom

    1997-01-01

    Computer hardware and associated software have been used for many years to process accounting information, to analyze test data and to perform engineering analysis. Now computers and software also control everything from automobiles to washing machines and the number and type of applications are growing at an exponential rate. The size of individual program has shown similar growth. Furthermore, software and hardware are used to monitor and/or control potentially dangerous products and safety-critical systems. These uses include everything from airplanes and braking systems to medical devices and nuclear plants. The question is: how can this hardware and software be made more reliable? Also, how can software quality be improved? What methodology needs to be provided on large and small software products to improve the design and how can software be verified?

  14. Evaluation of proton inelastic reaction models in Geant4 for prompt gamma production during proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Jeyasugiththan, Jeyasingam; Peterson, Stephen W.

    2015-10-01

    During proton beam radiotherapy, discrete secondary prompt gamma rays are induced by inelastic nuclear reactions between protons and nuclei in the human body. In recent years, the Geant4 Monte Carlo toolkit has played an important role in the development of a device for real time dose range verification purposes using prompt gamma radiation. Unfortunately the default physics models in Geant4 do not reliably replicate the measured prompt gamma emission. Determining a suitable physics model for low energy proton inelastic interactions will boost the accuracy of prompt gamma simulations. Among the built-in physics models, we found that the precompound model with a modified initial exciton state of 2 (1 particle, 1 hole) produced more accurate discrete gamma lines from the most important elements found within the body such as 16O, 12C and 14N when comparing them with the available gamma production cross section data. Using the modified physics model, we investigated the prompt gamma spectra produced in a water phantom by a 200 MeV pencil beam of protons. The spectra were attained using a LaBr3 detector with a time-of-flight (TOF) window and BGO active shield to reduce the secondary neutron and gamma background. The simulations show that a 2 ns TOF window could reduce 99% of the secondary neutron flux hitting the detector. The results show that using both timing and active shielding can remove up to 85% of the background radiation which includes a 33% reduction by BGO subtraction.

  15. Geant4 studies of the CNAO facility system for hadrontherapy treatment of uveal melanomas

    NASA Astrophysics Data System (ADS)

    Rimoldi, A.; Piersimoni, P.; Pirola, M.; Riccardi, C.

    2014-06-01

    The Italian National Centre of Hadrontherapy for Cancer Treatment (CNAO -Centro Nazionale di Adroterapia Oncologica) in Pavia, Italy, has started the treatment of selected cancers with the first patients in late 2011. In the coming months at CNAO plans are to activate a new dedicated treatment line for irradiation of uveal melanomas using the available active beam scan. The beam characteristics and the experimental setup should be tuned in order to reach the necessary precision required for such treatments. Collaboration between CNAO foundation, University of Pavia and INFN has started in 2011 to study the feasibility of these specialised treatments by implementing a MC simulation of the transport beam line and comparing the obtained simulation results with measurements at CNAO. The goal is to optimise an eye-dedicated transport beam line and to find the best conditions for ocular melanoma irradiations. This paper describes the Geant4 toolkit simulation of the CNAO setup as well as a modelised human eye with a tumour inside. The Geant4 application could be also used to test possible treatment planning systems. Simulation results illustrate the possibility to adapt the CNAO standard transport beam line by optimising the position of the isocentre and the addition of some passive elements to better shape the beam for this dedicated study.

  16. A Compton camera application for the GAMOS GEANT4-based framework

    NASA Astrophysics Data System (ADS)

    Harkness, L. J.; Arce, P.; Judson, D. S.; Boston, A. J.; Boston, H. C.; Cresswell, J. R.; Dormand, J.; Jones, M.; Nolan, P. J.; Sampson, J. A.; Scraggs, D. P.; Sweeney, A.; Lazarus, I.; Simpson, J.

    2012-04-01

    Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

  17. Multi-scale hybrid models for radiopharmaceutical dosimetry with Geant4.

    PubMed

    Marcatili, S; Villoing, D; Garcia, M P; Bardiès, M

    2014-12-21

    The accuracy of radiopharmaceutical absorbed dose distributions computed through Monte Carlo (MC) simulations is mostly limited by the low spatial resolution of 3D imaging techniques used to define the simulation geometry. This issue also persists with the implementation of realistic hybrid models built using polygonal mesh and/or NURBS as they require to be simulated in their voxel form in order to reduce computation times. The existing trade-off between voxel size and simulation speed leads on one side, in an overestimation of the size of small radiosensitive structures such as the skin or hollow organs walls and, on the other, to unnecessarily detailed voxelization of large, homogeneous structures.We developed a set of computational tools based on VTK and Geant4 in order to build multi-resolution organ models. Our aim is to use different voxel sizes to represent anatomical regions of different clinical relevance: the MC implementation of these models is expected to improve spatial resolution in specific anatomical structures without significantly affecting simulation speed. Here we present the tools developed through a proof of principle example. Our approach is validated against the standard Geant4 technique for the simulation of voxel geometries. PMID:25415621

  18. Enhancement and validation of Geant4 Brachytherapy application on clinical HDR 192Ir source

    NASA Astrophysics Data System (ADS)

    Ababneh, Eshraq; Dababneh, Saed; Qatarneh, Sharif; Wadi-Ramahi, Shada

    2014-10-01

    The Geant4 Monte Carlo MC associated Brachytherapy example was adapted, enhanced and several analysis techniques have been developed. The simulation studies the isodose distribution of the total, primary and scattered doses around a Nucletron microSelectron 192Ir source. Different phantom materials were used (water, tissue and bone) and the calculation was conducted at various depths and planes. The work provides an early estimate of the required number of primary events to ultimately achieve a given uncertainty at a given distance, in the otherwise CPU and time consuming clinical MC calculation. The adaptation of the Geant4 toolkit and the enhancements introduced to the code are all validated including the comprehensive decay of the 192Ir source, the materials used to build the geometry, the geometry itself and the calculated scatter to primary dose ratio. The simulation quantitatively illustrates that the scattered dose in the bone medium is larger than its value in water and tissue. As the distance away from the source increases, scatter contribution to dose becomes more significant as the primary dose decreases. The developed code could be viewed as a platform that contains detailed dose calculation model for clinical application of HDR 192Ir in Brachytherapy.

  19. Evaluation of proton inelastic reaction models in Geant4 for prompt gamma production during proton radiotherapy.

    PubMed

    Jeyasugiththan, Jeyasingam; Peterson, Stephen W

    2015-10-01

    During proton beam radiotherapy, discrete secondary prompt gamma rays are induced by inelastic nuclear reactions between protons and nuclei in the human body. In recent years, the Geant4 Monte Carlo toolkit has played an important role in the development of a device for real time dose range verification purposes using prompt gamma radiation. Unfortunately the default physics models in Geant4 do not reliably replicate the measured prompt gamma emission. Determining a suitable physics model for low energy proton inelastic interactions will boost the accuracy of prompt gamma simulations. Among the built-in physics models, we found that the precompound model with a modified initial exciton state of 2 (1 particle, 1 hole) produced more accurate discrete gamma lines from the most important elements found within the body such as 16O, 12C and 14N when comparing them with the available gamma production cross section data. Using the modified physics model, we investigated the prompt gamma spectra produced in a water phantom by a 200 MeV pencil beam of protons. The spectra were attained using a LaBr3 detector with a time-of-flight (TOF) window and BGO active shield to reduce the secondary neutron and gamma background. The simulations show that a 2 ns TOF window could reduce 99% of the secondary neutron flux hitting the detector. The results show that using both timing and active shielding can remove up to 85% of the background radiation which includes a 33% reduction by BGO subtraction. PMID:26389549

  20. Application of dynamic Monte Carlo technique in proton beam radiotherapy using Geant4 simulation toolkit

    NASA Astrophysics Data System (ADS)

    Guan, Fada

    Monte Carlo method has been successfully applied in simulating the particles transport problems. Most of the Monte Carlo simulation tools are static and they can only be used to perform the static simulations for the problems with fixed physics and geometry settings. Proton therapy is a dynamic treatment technique in the clinical application. In this research, we developed a method to perform the dynamic Monte Carlo simulation of proton therapy using Geant4 simulation toolkit. A passive-scattering treatment nozzle equipped with a rotating range modulation wheel was modeled in this research. One important application of the Monte Carlo simulation is to predict the spatial dose distribution in the target geometry. For simplification, a mathematical model of a human body is usually used as the target, but only the average dose over the whole organ or tissue can be obtained rather than the accurate spatial dose distribution. In this research, we developed a method using MATLAB to convert the medical images of a patient from CT scanning into the patient voxel geometry. Hence, if the patient voxel geometry is used as the target in the Monte Carlo simulation, the accurate spatial dose distribution in the target can be obtained. A data analysis tool---root was used to score the simulation results during a Geant4 simulation and to analyze the data and plot results after simulation. Finally, we successfully obtained the accurate spatial dose distribution in part of a human body after treating a patient with prostate cancer using proton therapy.

  1. Multi-scale hybrid models for radiopharmaceutical dosimetry with Geant4

    NASA Astrophysics Data System (ADS)

    Marcatili, S.; Villoing, D.; Garcia, M. P.; Bardiès, M.

    2014-12-01

    The accuracy of radiopharmaceutical absorbed dose distributions computed through Monte Carlo (MC) simulations is mostly limited by the low spatial resolution of 3D imaging techniques used to define the simulation geometry. This issue also persists with the implementation of realistic hybrid models built using polygonal mesh and/or NURBS as they require to be simulated in their voxel form in order to reduce computation times. The existing trade-off between voxel size and simulation speed leads on one side, in an overestimation of the size of small radiosensitive structures such as the skin or hollow organs walls and, on the other, to unnecessarily detailed voxelization of large, homogeneous structures. We developed a set of computational tools based on VTK and Geant4 in order to build multi-resolution organ models. Our aim is to use different voxel sizes to represent anatomical regions of different clinical relevance: the MC implementation of these models is expected to improve spatial resolution in specific anatomical structures without significantly affecting simulation speed. Here we present the tools developed through a proof of principle example. Our approach is validated against the standard Geant4 technique for the simulation of voxel geometries.

  2. Benchmarking nuclear models of FLUKA and GEANT4 for carbon ion therapy.

    PubMed

    Böhlen, T T; Cerutti, F; Dosanjh, M; Ferrari, A; Gudowska, I; Mairani, A; Quesada, J M

    2010-10-01

    As carbon ions, at therapeutic energies, penetrate tissue, they undergo inelastic nuclear reactions and give rise to significant yields of secondary fragment fluences. Therefore, an accurate prediction of these fluences resulting from the primary carbon interactions is necessary in the patient's body in order to precisely simulate the spatial dose distribution and the resulting biological effect. In this paper, the performance of nuclear fragmentation models of the Monte Carlo transport codes, FLUKA and GEANT4, in tissue-like media and for an energy regime relevant for therapeutic carbon ions is investigated. The ability of these Monte Carlo codes to reproduce experimental data of charge-changing cross sections and integral and differential yields of secondary charged fragments is evaluated. For the fragment yields, the main focus is on the consideration of experimental approximations and uncertainties such as the energy measurement by time-of-flight. For GEANT4, the hadronic models G4BinaryLightIonReaction and G4QMD are benchmarked together with some recently enhanced de-excitation models. For non-differential quantities, discrepancies of some tens of percent are found for both codes. For differential quantities, even larger deviations are found. Implications of these findings for the therapeutic use of carbon ions are discussed. PMID:20844337

  3. Simulation of positron backscattering and implantation profiles using Geant4 code

    NASA Astrophysics Data System (ADS)

    Huang, Shi-Juan; Pan, Zi-Wen; Liu, Jian-Dang; Han, Rong-Dian; Ye, Bang-Jiao

    2015-10-01

    For the proper interpretation of the experimental data produced in slow positron beam technique, the positron implantation properties are studied carefully using the latest Geant4 code. The simulated backscattering coefficients, the implantation profiles, and the median implantation depths for mono-energetic positrons with energy range from 1 keV to 50 keV normally incident on different crystals are reported. Compared with the previous experimental results, our simulation backscattering coefficients are in reasonable agreement, and we think that the accuracy may be related to the structures of the host materials in the Geant4 code. Based on the reasonable simulated backscattering coefficients, the adjustable parameters of the implantation profiles which are dependent on materials and implantation energies are obtained. The most important point is that we calculate the positron backscattering coefficients and median implantation depths in amorphous polymers for the first time and our simulations are in fairly good agreement with the previous experimental results. Project supported by the National Natural Science Foundation of China (Grant Nos. 11175171 and 11105139).

  4. Working Notes from the 1992 AAAI Workshop on Automating Software Design. Theme: Domain Specific Software Design

    NASA Technical Reports Server (NTRS)

    Keller, Richard M. (Editor); Barstow, David; Lowry, Michael R.; Tong, Christopher H.

    1992-01-01

    The goal of this workshop is to identify different architectural approaches to building domain-specific software design systems and to explore issues unique to domain-specific (vs. general-purpose) software design. Some general issues that cut across the particular software design domain include: (1) knowledge representation, acquisition, and maintenance; (2) specialized software design techniques; and (3) user interaction and user interface.

  5. Software Prototyping: Designing Systems for Users.

    ERIC Educational Resources Information Center

    Spies, Phyllis Bova

    1983-01-01

    Reports on major change in computer software development process--the prototype model, i.e., implementation of skeletal system that is enhanced during interaction with users. Expensive and unreliable software, software design errors, traditional development approach, resources required for prototyping, success stories, and systems designer's role…

  6. Flight Software Design Choices Based on Criticality

    NASA Technical Reports Server (NTRS)

    Lee, Earl

    1999-01-01

    This slide presentation reviews the rationale behind flight software design as a function of criticality. The requirements of human rated systems implies a high criticality for the flight support software. Human life is dependent on correct operation of the software. Flexibility should be permitted when the consequences of software failure are not life threatening. This is also relevant for selecting Commercial Off the Shelf (COTS) software.

  7. The impact of new Geant4-DNA cross section models on electron track structure simulations in liquid water

    NASA Astrophysics Data System (ADS)

    Kyriakou, I.; Šefl, M.; Nourry, V.; Incerti, S.

    2016-05-01

    The most recent release of the open source and general purpose Geant4 Monte Carlo simulation toolkit (Geant4 10.2 release) contains a new set of physics models in the Geant4-DNA extension for improving the modelling of low-energy electron transport in liquid water (<10 keV). This includes updated electron cross sections for excitation, ionization, and elastic scattering. In the present work, the impact of these developments to track-structure calculations is examined for providing the first comprehensive comparison against the default physics models of Geant4-DNA. Significant differences with the default models are found for the average path length and penetration distance, as well as for dose-point-kernels for electron energies below a few hundred eV. On the other hand, self-irradiation absorbed fractions for tissue-like volumes and low-energy electron sources (including some Auger emitters) reveal rather small differences (up to 15%) between these new and default Geant4-DNA models. The above findings indicate that the impact of the new developments will mainly affect those applications where the spatial pattern of interactions and energy deposition of very-low energy electrons play an important role such as, for example, the modelling of the chemical and biophysical stage of radiation damage to cells.

  8. Purchasing Computer-Aided Design Software.

    ERIC Educational Resources Information Center

    Smith, Roger A.

    1992-01-01

    Presents a model for the purchase of computer-aided design (CAD) software: collect general information, observe CAD in use, arrange onsite demonstrations, select CAD software and hardware, and choose a vendor. (JOW)

  9. Calculation of extrapolation curves in the 4π(LS)β-γ coincidence technique with the Monte Carlo code Geant4.

    PubMed

    Bobin, C; Thiam, C; Bouchard, J

    2016-03-01

    At LNE-LNHB, a liquid scintillation (LS) detection setup designed for Triple to Double Coincidence Ratio (TDCR) measurements is also used in the β-channel of a 4π(LS)β-γ coincidence system. This LS counter based on 3 photomultipliers was first modeled using the Monte Carlo code Geant4 to enable the simulation of optical photons produced by scintillation and Cerenkov effects. This stochastic modeling was especially designed for the calculation of double and triple coincidences between photomultipliers in TDCR measurements. In the present paper, this TDCR-Geant4 model is extended to 4π(LS)β-γ coincidence counting to enable the simulation of the efficiency-extrapolation technique by the addition of a γ-channel. This simulation tool aims at the prediction of systematic biases in activity determination due to eventual non-linearity of efficiency-extrapolation curves. First results are described in the case of the standardization (59)Fe. The variation of the γ-efficiency in the β-channel due to the Cerenkov emission is investigated in the case of the activity measurements of (54)Mn. The problem of the non-linearity between β-efficiencies is featured in the case of the efficiency tracing technique for the activity measurements of (14)C using (60)Co as a tracer. PMID:26699674

  10. Comparative studies on shielding properties of some steel alloys using Geant4, MCNP, WinXCOM and experimental results

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Medhat, M. E.; Shirmardi, S. P.

    2015-01-01

    The mass attenuation coefficients, μ/ρ and effective atomic numbers, Zeff of some carbon steel and stainless steel alloys have been calculated by using Geant4, MCNP simulation codes for different gamma ray energies, 279.1 keV, 661.6 keV, 662 keV, 1115.5 keV, 1173 keV and 1332 keV. The simulation results of Zeff using Geant4 and MCNP codes have been compared with possible available experimental results and theoretical WinXcom, and good agreement has been observed. The simulated μ/ρ and Zeff values using Geant4 and MCNP code signifies that both the simulation process can be followed to determine the gamma ray interaction properties of the alloys for energies wherever analogous experimental results may not be available. This kind of studies can be used for various applications such as for radiation dosimetry, medical and radiation shielding.

  11. 3D polymer gel dosimetry and Geant4 Monte Carlo characterization of novel needle based X-ray source

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Sozontov, E.; Safronov, V.; Gutman, G.; Strumban, E.; Jiang, Q.; Li, S.

    2010-11-01

    In the recent years, there have been a few attempts to develop a low energy x-ray radiation sources alternative to conventional radioisotopes used in brachytherapy. So far, all efforts have been centered around the intent to design an interstitial miniaturized x-ray tube. Though direct irradiation of tumors looks very promising, the known insertable miniature x-ray tubes have many limitations: (a) difficulties with focusing and steering the electron beam to the target; (b)necessity to cool the target to increase x-ray production efficiency; (c)impracticability to reduce the diameter of the miniaturized x-ray tube below 4mm (the requirement to decrease the diameter of the x-ray tube and the need to have a cooling system for the target have are mutually exclusive); (c) significant limitations in changing shape and energy of the emitted radiation. The specific aim of this study is to demonstrate the feasibility of a new concept for an insertable low-energy needle x-ray device based on simulation with Geant4 Monte Carlo code and to measure the dose rate distribution for low energy (17.5 keV) x-ray radiation with the 3D polymer gel dosimetry.

  12. Galactic Cosmic Rays and Lunar Secondary Particles from Solar Minimum to Maximum: CRaTER Observations and Geant4 Modeling

    NASA Astrophysics Data System (ADS)

    Looper, M. D.; Mazur, J. E.; Blake, J. B.; Spence, H. E.; Schwadron, N.; Golightly, M. J.; Case, A. W.; Kasper, J. C.; Townsend, L. W.; Wilson, J. K.

    2014-12-01

    The Lunar Reconnaissance Orbiter mission was launched in 2009 during the recent deep and extended solar minimum, with the highest galactic cosmic ray (GCR) fluxes observed since the beginning of the space era. Its Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument was designed to measure the spectra of energy deposits in silicon detectors shielded behind pieces of tissue equivalent plastic, simulating the self-shielding provided by an astronaut's body around radiation-sensitive organs. The CRaTER data set now covers the evolution of the GCR environment near the moon during the first five years of development of the present solar cycle. We will present these observations, along with Geant4 modeling to illustrate the varying particle contributions to the energy-deposit spectra. CRaTER has also measured protons traveling up from the lunar surface after their creation during GCR interactions with surface material, and we will report observations and modeling of the energy and angular distributions of these "albedo" protons.

  13. Efficient voxel navigation for proton therapy dose calculation in TOPAS and Geant4

    NASA Astrophysics Data System (ADS)

    Schümann, J.; Paganetti, H.; Shin, J.; Faddegon, B.; Perl, J.

    2012-06-01

    A key task within all Monte Carlo particle transport codes is ‘navigation’, the calculation to determine at each particle step what volume the particle may be leaving and what volume the particle may be entering. Navigation should be optimized to the specific geometry at hand. For patient dose calculation, this geometry generally involves voxelized computed tomography (CT) data. We investigated the efficiency of navigation algorithms on currently available voxel geometry parameterizations in the Monte Carlo simulation package Geant4: G4VPVParameterisation, G4VNestedParameterisation and G4PhantomParameterisation, the last with and without boundary skipping, a method where neighboring voxels with the same Hounsfield unit are combined into one larger voxel. A fourth parameterization approach (MGHParameterization), developed in-house before the latter two parameterizations became available in Geant4, was also included in this study. All simulations were performed using TOPAS, a tool for particle simulations layered on top of Geant4. Runtime comparisons were made on three distinct patient CT data sets: a head and neck, a liver and a prostate patient. We included an additional version of these three patients where all voxels, including the air voxels outside of the patient, were uniformly set to water in the runtime study. The G4VPVParameterisation offers two optimization options. One option has a 60-150 times slower simulation speed. The other is compatible in speed but requires 15-19 times more memory compared to the other parameterizations. We found the average CPU time used for the simulation relative to G4VNestedParameterisation to be 1.014 for G4PhantomParameterisation without boundary skipping and 1.015 for MGHParameterization. The average runtime ratio for G4PhantomParameterisation with and without boundary skipping for our heterogeneous data was equal to 0.97: 1. The calculated dose distributions agreed with the reference distribution for all but the G4

  14. Efficient voxel navigation for proton therapy dose calculation in TOPAS and Geant4.

    PubMed

    Schümann, J; Paganetti, H; Shin, J; Faddegon, B; Perl, J

    2012-06-01

    A key task within all Monte Carlo particle transport codes is 'navigation', the calculation to determine at each particle step what volume the particle may be leaving and what volume the particle may be entering. Navigation should be optimized to the specific geometry at hand. For patient dose calculation, this geometry generally involves voxelized computed tomography (CT) data. We investigated the efficiency of navigation algorithms on currently available voxel geometry parameterizations in the Monte Carlo simulation package Geant4: G4VPVParameterisation, G4VNestedParameterisation and G4PhantomParameterisation, the last with and without boundary skipping, a method where neighboring voxels with the same Hounsfield unit are combined into one larger voxel. A fourth parameterization approach (MGHParameterization), developed in-house before the latter two parameterizations became available in Geant4, was also included in this study. All simulations were performed using TOPAS, a tool for particle simulations layered on top of Geant4. Runtime comparisons were made on three distinct patient CT data sets: a head and neck, a liver and a prostate patient. We included an additional version of these three patients where all voxels, including the air voxels outside of the patient, were uniformly set to water in the runtime study. The G4VPVParameterisation offers two optimization options. One option has a 60-150 times slower simulation speed. The other is compatible in speed but requires 15-19 times more memory compared to the other parameterizations. We found the average CPU time used for the simulation relative to G4VNestedParameterisation to be 1.014 for G4PhantomParameterisation without boundary skipping and 1.015 for MGHParameterization. The average runtime ratio for G4PhantomParameterisation with and without boundary skipping for our heterogeneous data was equal to 0.97: 1. The calculated dose distributions agreed with the reference distribution for all but the G4Phantom

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

    NASA Astrophysics Data System (ADS)

    Incerti, S.; Suerfu, B.; Xu, J.; Ivantchenko, V.; Mantero, A.; Brown, J. M. C.; Bernal, M. A.; Francis, Z.; Karamitros, M.; Tran, H. N.

    2016-04-01

    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.

  16. Molecular scale track structure simulations in liquid water using the Geant4-DNA Monte-Carlo processes.

    PubMed

    Francis, Z; Incerti, S; Capra, R; Mascialino, B; Montarou, G; Stepan, V; Villagrasa, C

    2011-01-01

    This paper presents a study of energy deposits induced by ionising particles in liquid water at the molecular scale. Particles track structures were generated using the Geant4-DNA processes of the Geant4 Monte-Carlo toolkit. These processes cover electrons (0.025 eV-1 MeV), protons (1 keV-100 MeV), hydrogen atoms (1 keV-100 MeV) and alpha particles (10 keV-40 MeV) including their different charge states. Electron ranges and lineal energies for protons were calculated in nanometric and micrometric volumes. PMID:20810287

  17. Using Software Design Methods in CALL

    ERIC Educational Resources Information Center

    Ward, Monica

    2006-01-01

    The phrase "software design" is not one that arouses the interest of many CALL practitioners, particularly those from a humanities background. However, software design essentials are simply logical ways of going about designing a system. The fundamentals include modularity, anticipation of change, generality and an incremental approach. While CALL…

  18. Language and Program for Documenting Software Design

    NASA Technical Reports Server (NTRS)

    Kleine, H.; Zepko, T. M.

    1986-01-01

    Software Design and Documentation Language (SDDL) provides effective communication medium to support design and documentation of complex software applications. SDDL supports communication among all members of software design team and provides for production of informative documentation on design effort. Use of SDDL-generated document to analyze design makes it possible to eliminate many errors not detected until coding and testing attempted. SDDL processor program translates designer's creative thinking into effective document for communication. Processor performs as many automatic functions as possible, freeing designer's energy for creative effort. SDDL processor program written in PASCAL.

  19. Knowledge modeling for software design

    NASA Technical Reports Server (NTRS)

    Shaw, Mildred L. G.; Gaines, Brian R.

    1992-01-01

    This paper develops a modeling framework for systems engineering that encompasses systems modeling, task modeling, and knowledge modeling, and allows knowledge engineering and software engineering to be seen as part of a unified developmental process. This framework is used to evaluate what novel contributions the 'knowledge engineering' paradigm has made and how these impact software engineering.

  20. Radiation quality of cosmic ray nuclei studied with Geant4-based simulations

    NASA Astrophysics Data System (ADS)

    Burigo, Lucas N.; Pshenichnov, Igor A.; Mishustin, Igor N.; Bleicher, Marcus

    2014-04-01

    In future missions in deep space a space craft will be exposed to a non-negligible flux of high charge and energy (HZE) particles present in the galactic cosmic rays (GCR). One of the major concerns of manned missions is the impact on humans of complex radiation fields which result from the interactions of HZE particles with the spacecraft materials. The radiation quality of several ions representing GCR is investigated by calculating microdosimetry spectra. A Geant4-based Monte Carlo model for Heavy Ion Therapy (MCHIT) is used to simulate microdosimetry data for HZE particles in extended media where fragmentation reactions play a certain role. Our model is able to reproduce measured microdosimetry spectra for H, He, Li, C and Si in the energy range of 150-490 MeV/u. The effect of nuclear fragmentation on the relative biological effectiveness (RBE) of He, Li and C is estimated and found to be below 10%.

  1. Nuclear reaction measurements on tissue-equivalent materials and GEANT4 Monte Carlo simulations for hadrontherapy

    NASA Astrophysics Data System (ADS)

    De Napoli, M.; Romano, F.; D'Urso, D.; Licciardello, T.; Agodi, C.; Candiano, G.; Cappuzzello, F.; Cirrone, G. A. P.; Cuttone, G.; Musumarra, A.; Pandola, L.; Scuderi, V.

    2014-12-01

    When a carbon beam interacts with human tissues, many secondary fragments are produced into the tumor region and the surrounding healthy tissues. Therefore, in hadrontherapy precise dose calculations require Monte Carlo tools equipped with complex nuclear reaction models. To get realistic predictions, however, simulation codes must be validated against experimental results; the wider the dataset is, the more the models are finely tuned. Since no fragmentation data for tissue-equivalent materials at Fermi energies are available in literature, we measured secondary fragments produced by the interaction of a 55.6 MeV u-1 12C beam with thick muscle and cortical bone targets. Three reaction models used by the Geant4 Monte Carlo code, the Binary Light Ions Cascade, the Quantum Molecular Dynamic and the Liege Intranuclear Cascade, have been benchmarked against the collected data. In this work we present the experimental results and we discuss the predictive power of the above mentioned models.

  2. G4SiPM: A novel silicon photomultiplier simulation package for Geant4

    NASA Astrophysics Data System (ADS)

    Niggemann, Tim; Dietz-Laursonn, Erik; Hebbeker, Thomas; Künsken, Andreas; Lauscher, Markus; Merschmeyer, Markus

    2015-07-01

    The signal of silicon photomultipliers (SiPMs) depends not only on the number of incoming photons but also on thermal and correlated noise of which the latter is difficult to handle. Additionally, the properties of SiPMs vary with the supplied bias voltage and the ambient temperature. The purpose of the G4SiPM simulation package is the integration of a detailed SiPM simulation into Geant4 which is widely used in particle physics. The prediction of the G4SiPM simulation code is validated with a laboratory measurement of the dynamic range of a 3×3 mm2 SiPM with 3600 cells manufactured by Hamamatsu.

  3. Geant4 simulation of the n_TOF-EAR2 neutron beam: Characteristics and prospects

    NASA Astrophysics Data System (ADS)

    Lerendegui-Marco, J.; Lo Meo, S.; Guerrero, C.; Cortés-Giraldo, M. A.; Massimi, C.; Quesada, J. M.; Barbagallo, M.; Colonna, N.; Mancusi, D.; Mingrone, F.; Sabaté-Gilarte, M.; Vannini, G.; Vlachoudis, V.

    2016-04-01

    The characteristics of the neutron beam at the new n_TOF-EAR2 facility have been simulated with the Geant4 code with the aim of providing useful data for both the analysis and planning of the upcoming measurements. The spatial and energy distributions of the neutrons, the resolution function and the in-beam γ-ray background have been studied in detail and their implications in the forthcoming experiments have been discussed. The results confirm that, with this new short (18.5m flight path) beam line, reaching an instantaneous neutron flux beyond 105n/μs/pulse in the keV region, n_TOF is one of the few facilities where challenging measurements can be performed, involving in particular short-lived radioisotopes.

  4. Geant4 Predictions of Energy Spectra in Typical Space Radiation Environment

    NASA Technical Reports Server (NTRS)

    Sabra, M. S.; Barghouty, A. F.

    2014-01-01

    Accurate knowledge of energy spectra inside spacecraft is important for protecting astronauts as well as sensitive electronics from the harmful effects of space radiation. Such knowledge allows one to confidently map the radiation environment inside the vehicle. The purpose of this talk is to present preliminary calculations for energy spectra inside a spherical shell shielding and behind a slab in typical space radiation environment using the 3D Monte-Carlo transport code Geant4. We have simulated proton and iron isotropic sources and beams impinging on Aluminum and Gallium arsenide (GaAs) targets at energies of 0.2, 0.6, 1, and 10 GeV/u. If time permits, other radiation sources and beams (_, C, O) and targets (C, Si, Ge, water) will be presented. The results are compared to ground-based measurements where available.

  5. Geant4.10 simulation of geometric model for metaphase chromosome

    NASA Astrophysics Data System (ADS)

    Rafat-Motavalli, L.; Miri-Hakimabad, H.; Bakhtiyari, E.

    2016-04-01

    In this paper, a geometric model of metaphase chromosome is explained. The model is constructed according to the packing ratio and dimension of the structure from nucleosome up to chromosome. A B-DNA base pair is used to construct 200 base pairs of nucleosomes. Each chromatin fiber loop, which is the unit of repeat, has 49,200 bp. This geometry is entered in Geant4.10 Monte Carlo simulation toolkit and can be extended to the whole metaphase chromosomes and any application in which a DNA geometrical model is needed. The chromosome base pairs, chromosome length, and relative length of chromosomes are calculated. The calculated relative length is compared to the relative length of human chromosomes.

  6. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy.

    PubMed

    Afsharpour, H; Landry, G; D'Amours, M; Enger, S; Reniers, B; Poon, E; Carrier, J-F; Verhaegen, F; Beaulieu, L

    2012-06-01

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy. PMID:22572100

  7. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy

    NASA Astrophysics Data System (ADS)

    Afsharpour, H.; Landry, G.; D'Amours, M.; Enger, S.; Reniers, B.; Poon, E.; Carrier, J.-F.; Verhaegen, F.; Beaulieu, L.

    2012-06-01

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  8. Development and validation of a GEANT4 radiation transport code for CT dosimetry

    PubMed Central

    Carver, DE; Kost, SD; Fernald, MJ; Lewis, KG; Fraser, ND; Pickens, DR; Price, RR; Stabin, MG

    2014-01-01

    We have created a radiation transport code using the GEANT4 Monte Carlo toolkit to simulate pediatric patients undergoing CT examinations. The focus of this paper is to validate our simulation with real-world physical dosimetry measurements using two independent techniques. Exposure measurements were made with a standard 100-mm CT pencil ionization chamber, and absorbed doses were also measured using optically stimulated luminescent (OSL) dosimeters. Measurements were made in air, a standard 16-cm acrylic head phantom, and a standard 32-cm acrylic body phantom. Physical dose measurements determined from the ionization chamber in air for 100 and 120 kVp beam energies were used to derive photon-fluence calibration factors. Both ion chamber and OSL measurement results provide useful comparisons in the validation of our Monte Carlo simulations. We found that simulated and measured CTDI values were within an overall average of 6% of each other. PMID:25706135

  9. Geant4 calculations for space radiation shielding material Al2O3

    NASA Astrophysics Data System (ADS)

    Capali, Veli; Acar Yesil, Tolga; Kaya, Gokhan; Kaplan, Abdullah; Yavuz, Mustafa; Tilki, Tahir

    2015-07-01

    Aluminium Oxide, Al2O3 is the most widely used material in the engineering applications. It is significant aluminium metal, because of its hardness and as a refractory material owing to its high melting point. This material has several engineering applications in diverse fields such as, ballistic armour systems, wear components, electrical and electronic substrates, automotive parts, components for electric industry and aero-engine. As well, it is used as a dosimeter for radiation protection and therapy applications for its optically stimulated luminescence properties. In this study, stopping powers and penetrating distances have been calculated for the alpha, proton, electron and gamma particles in space radiation shielding material Al2O3 for incident energies 1 keV - 1 GeV using GEANT4 calculation code.

  10. Comparison of MCNPX and Geant4 proton energy deposition predictions for clinical use

    PubMed Central

    Titt, U.; Bednarz, B.; Paganetti, H.

    2012-01-01

    Several different Monte Carlo codes are currently being used at proton therapy centers to improve upon dose predictions over standard methods using analytical or semi-empirical dose algorithms. There is a need to better ascertain the differences between proton dose predictions from different available Monte Carlo codes. In this investigation Geant4 and MCNPX, the two most-utilized Monte Carlo codes for proton therapy applications, were used to predict energy deposition distributions in a variety of geometries, comprising simple water phantoms, water phantoms with complex inserts and in a voxelized geometry based on clinical CT data. The gamma analysis was used to evaluate the differences of the predictions between the codes. The results show that in the all cases the agreement was better than clinical acceptance criteria. PMID:22996039

  11. Signal pulse emulation for scintillation detectors using Geant4 Monte Carlo with light tracking simulation

    NASA Astrophysics Data System (ADS)

    Ogawara, R.; Ishikawa, M.

    2016-07-01

    The anode pulse of a photomultiplier tube (PMT) coupled with a scintillator is used for pulse shape discrimination (PSD) analysis. We have developed a novel emulation technique for the PMT anode pulse based on optical photon transport and a PMT response function. The photon transport was calculated using Geant4 Monte Carlo code and the response function with a BC408 organic scintillator. The obtained percentage RMS value of the difference between the measured and simulated pulse with suitable scintillation properties using GSO:Ce (0.4, 1.0, 1.5 mol%), LaBr3:Ce and BGO scintillators were 2.41%, 2.58%, 2.16%, 2.01%, and 3.32%, respectively. The proposed technique demonstrates high reproducibility of the measured pulse and can be applied to simulation studies of various radiation measurements.

  12. GEANT4 Application for the Simulation of the Head of a Siemens Primus Linac

    SciTech Connect

    Cortes-Giraldo, M. A.; Quesada, J. M.; Gallardo, M. I.

    2010-04-26

    The Monte Carlo simulation of the head of a Siemens Primus Linac used at Virgen Macarena Hospital (Sevilla, Spain) has been performed using the code GEANT4, version 9.2. In this work, the main features of the application built by our group are presented. They are mainly focused in the optimization of the performance of the simulation. The geometry, including the water phantom, has been entirely wrapped by a shielding volume which discards all the particles escaping far away through its walls. With this, a factor of four in the time spent by the simulation can be saved. An interface to read and write phase-space files in IAEA format has been also developed to save CPU time in our simulations. Finally, some calculations of the dose absorption in the water phantom have been done and compared with the results given by EGSnrc and with experimental data obtained for the calibration of the machine.

  13. Geant4 Simulations of SuperCDMS iZip Detector Charge Carrier Propagation

    NASA Astrophysics Data System (ADS)

    Agnese, Robert; Brandt, Daniel; Redl, Peter; Asai, Makoto; Faiez, Dana; Kelsey, Mike; Bagli, Enrico; Anderson, Adam; Schlupf, Chandler

    2014-03-01

    The SuperCDMS experiment uses germanium crystal detectors instrumented with ionization and phonon readout circuits to search for dark matter. In order to simulate the response of the detectors to particle interactions the SuperCDMS Detector Monte Carlo (DMC) group has been implementing the processes governing electrons and phonons at low temperatures in Geant4. The charge portion of the DMC simulates oblique propagation of the electrons through the L-valleys, propagation of holes through the Γ-valleys, inter-valley scattering, and emission of Neganov-Luke phonons in a complex applied electric field. The field is calculated by applying a directed walk search on a tetrahedral mesh of known potentials and then interpolating the value. This talk will present an overview of the DMC status and a comparison of the charge portion of the DMC to experimental data of electron-hole pair propagation in germanium.

  14. Comparing Geant4 hadronic models for the WENDI-II rem meter response function.

    PubMed

    Vanaudenhove, T; Dubus, A; Pauly, N

    2013-01-01

    The WENDI-II rem meter is one of the most popular neutron dosemeters used to assess a useful quantity of radiation protection, namely the ambient dose equivalent. This is due to its high sensitivity and its energy response that approximately follows the conversion function between neutron fluence and ambient dose equivalent in the range of thermal to 5 GeV. The simulation of the WENDI-II response function with the Geant4 toolkit is then perfectly suited to compare low- and high-energy hadronic models provided by this Monte Carlo code. The results showed that the thermal treatment of hydrogen in polyethylene for neutron <4 eV has a great influence over the whole detector range. Above 19 MeV, both Bertini Cascade and Binary Cascade models show a good correlation with the results found in the literature, while low-energy parameterised models are not suitable for this application. PMID:22972796

  15. Modeling spallation reactions in tungsten and uranium targets with the Geant4 toolkit

    NASA Astrophysics Data System (ADS)

    Malyshkin, Yury; Pshenichnov, Igor; Mishustin, Igor; Greiner, Walter

    2012-02-01

    We study primary and secondary reactions induced by 600 MeV proton beams in monolithic cylindrical targets made of natural tungsten and uranium by using Monte Carlo simulations with the Geant4 toolkit [1-3]. Bertini intranuclear cascade model, Binary cascade model and IntraNuclear Cascade Liège (INCL) with ABLA model [4] were used as calculational options to describe nuclear reactions. Fission cross sections, neutron multiplicity and mass distributions of fragments for 238U fission induced by 25.6 and 62.9 MeV protons are calculated and compared to recent experimental data [5]. Time distributions of neutron leakage from the targets and heat depositions are calculated. This project is supported by Siemens Corporate Technology.

  16. Evaluation using GEANT4 of the transit dose in the Tunisian gamma irradiator for insect sterilization.

    PubMed

    Mannai, K; Askri, B; Loussaief, A; Trabelsi, A

    2007-06-01

    A simulation study of the Tunisian Gamma Irradiation Facility for sterile insects release programs has been realized using the GEANT4 Monte Carlo code of CERN. The dose was calculated and measured for high and low dose values inside the irradiation cell. The calculated high dose was in good agreement with measurements. However, a discrepancy between calculated and measured values occurs at dose levels commonly used for sterilization of insects. We argue that this discrepancy is due to the transit dose absorbed during displacement of targets from their initial position towards their irradiation position and displacement of radiation source pencils from storage towards their irradiation position. The discrepancy is corrected by taking into account the transit dose. PMID:17395474

  17. Performance of the Nab segmented silicon detectors: GEANT4 and data

    NASA Astrophysics Data System (ADS)

    Frlez, Emil; Nab Collaboration

    2015-10-01

    The Nab Collaboration has proposed to measure neutron β-decay correlation parameters a and b at the Oak Ridge National Laboratory using a custom superconducting spectrometer and novel Si detectors. Two large area 2-mm thick silicon detectors, each segmented into 127 hexagonal pixels, will be used to detect the proton and electron from cold neutron decay. We present GEANT4 Monte Carlo simulations of the Si detector energy and timing responses to electrons below 1 MeV and to 30 keV protons with realistic simulated amplified anode waveforms. Both the data acquired with a prototype detector at Los Alamos National Laboratory with radioactive sources and the synthetic waveforms are analyzed by the same code. Energy and timing responses of the Si detectors are discussed, with the MC waveforms calibrated to the decay constants, baselines, noise, gains, and timing offsets extracted from measured data, pixel by pixel. Work supported by NSF Grants PHY-1126683, 1205833, 1307328, 1506320, and others.

  18. GEANT4 calibration of gamma spectrometry efficiency for measurements of airborne radioactivity on filter paper.

    PubMed

    Alrefae, Tareq

    2014-11-01

    A simple method of efficiency calibration for gamma spectrometry was performed. This method, which focused on measuring airborne radioactivity collected on filter paper, was based on Monte Carlo simulations using the toolkit GEANT4. Experimentally, the efficiency values of an HPGe detector were calculated for a multi-gamma disk source. These efficiency values were compared to their counterparts produced by a computer code that simulated experimental conditions. Such comparison revealed biases of 24, 10, 1, 3, 7, and 3% for the radionuclides (photon energies in keV) of Ce (166), Sn (392), Cs (662), Co (1,173), Co (1,333), and Y (1,836), respectively. The output of the simulation code was in acceptable agreement with the experimental findings, thus validating the proposed method. PMID:25271933

  19. Development and validation of a GEANT4 radiation transport code for CT dosimetry.

    PubMed

    Carver, D E; Kost, S D; Fernald, M J; Lewis, K G; Fraser, N D; Pickens, D R; Price, R R; Stabin, M G

    2015-04-01

    The authors have created a radiation transport code using the GEANT4 Monte Carlo toolkit to simulate pediatric patients undergoing CT examinations. The focus of this paper is to validate their simulation with real-world physical dosimetry measurements using two independent techniques. Exposure measurements were made with a standard 100-mm CT pencil ionization chamber, and absorbed doses were also measured using optically stimulated luminescent (OSL) dosimeters. Measurements were made in air with a standard 16-cm acrylic head phantom and with a standard 32-cm acrylic body phantom. Physical dose measurements determined from the ionization chamber in air for 100 and 120 kVp beam energies were used to derive photon-fluence calibration factors. Both ion chamber and OSL measurement results provide useful comparisons in the validation of the Monte Carlo simulations. It was found that simulated and measured CTDI values were within an overall average of 6% of each other. PMID:25706135

  20. Geant4 predictions of energy spectra in typical space radiation environment

    NASA Astrophysics Data System (ADS)

    Sabra, M. S.; Barghouty, A. F.

    2014-03-01

    Accurate knowledge of energy spectra inside spacecraft is important for protecting astronauts as well as sensitive electronics from the harmful effects of space radiation. Such knowledge allows one to confidently map the radiation environment inside the vehicle. The purpose of this talk is to present preliminary calculations for energy spectra inside a spherical shell shielding and behind a slab in typical space radiation environment using the 3D Monte-Carlo transport code Geant4. We have simulated proton and iron isotropic sources and beams impinging on Aluminum and Gallium arsenide (GaAs) targets at energies of 0.2, 0.6, 1, and 10 GeV/u. If time permits, other radiation sources and beams (α, C, O) and targets (C, Si, Ge, water) will be presented. The results are compared to ground-based measurements where available.

  1. ROSI and GEANT4 - A comparison in the context of high energy X-ray physics

    NASA Astrophysics Data System (ADS)

    Kiunke, Markus; Stritt, Carina; Schielein, Richard; Sukowski, Frank; Hölzing, Astrid; Zabler, Simon; Hofmann, Jürgen; Flisch, Alexander; Kasperl, Stefan; Sennhauser, Urs; Hanke, Randolf

    2016-06-01

    This work compares two popular MC simulation frameworks ROSI (Roentgen Simulation) and GEANT4 (Geometry and Tracking in its fourth version) in the context of X-ray physics. The comparison will be performed with the help of a parameter study considering energy, material and length variations. While the total deposited energy as well as the contribution of Compton scattering show a good accordance between all simulated configurations, all other physical effects exhibit large deviations in a comparison of data-sets. These discrepancies between simulations are shown to originate from the different cross sectional databases used in the frameworks, whereas the overall simulation mechanics seem to not have an influence on the agreement of the simulations. A scan over energy, length and material shows that the two parameters energy and material have a significant influence on the agreement of the simulation results, while the length parameter shows no noticeable influence on the deviations between the data-sets.

  2. Application of Design Patterns in Refactoring Software Design

    NASA Technical Reports Server (NTRS)

    Baggs. Rjpda; Shaykhian, Gholam Ali

    2007-01-01

    Refactoring software design is a method of changing software design while explicitly preserving its unique design functionalities. Presented approach is to utilize design patterns as the basis for refactoring software design. Comparison of a design solution will be made through C++ programming language examples to exploit this approach. Developing reusable component will be discussed, the paper presents that the construction of such components can diminish the added burden of both refactoring and the use of design patterns.

  3. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications.

    PubMed

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled (125)I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10(-6) simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications. PMID:26061230

  4. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

    PubMed

    Chagren, S; Ben Tekaya, M; Reguigui, N; Gharbi, F

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. PMID:26623928

  5. GGEMS-Brachy: GPU GEant4-based Monte Carlo simulation for brachytherapy applications

    NASA Astrophysics Data System (ADS)

    Lemaréchal, Yannick; Bert, Julien; Falconnet, Claire; Després, Philippe; Valeri, Antoine; Schick, Ulrike; Pradier, Olivier; Garcia, Marie-Paule; Boussion, Nicolas; Visvikis, Dimitris

    2015-07-01

    In brachytherapy, plans are routinely calculated using the AAPM TG43 formalism which considers the patient as a simple water object. An accurate modeling of the physical processes considering patient heterogeneity using Monte Carlo simulation (MCS) methods is currently too time-consuming and computationally demanding to be routinely used. In this work we implemented and evaluated an accurate and fast MCS on Graphics Processing Units (GPU) for brachytherapy low dose rate (LDR) applications. A previously proposed Geant4 based MCS framework implemented on GPU (GGEMS) was extended to include a hybrid GPU navigator, allowing navigation within voxelized patient specific images and analytically modeled 125I seeds used in LDR brachytherapy. In addition, dose scoring based on track length estimator including uncertainty calculations was incorporated. The implemented GGEMS-brachy platform was validated using a comparison with Geant4 simulations and reference datasets. Finally, a comparative dosimetry study based on the current clinical standard (TG43) and the proposed platform was performed on twelve prostate cancer patients undergoing LDR brachytherapy. Considering patient 3D CT volumes of 400  × 250  × 65 voxels and an average of 58 implanted seeds, the mean patient dosimetry study run time for a 2% dose uncertainty was 9.35 s (≈500 ms 10-6 simulated particles) and 2.5 s when using one and four GPUs, respectively. The performance of the proposed GGEMS-brachy platform allows envisaging the use of Monte Carlo simulation based dosimetry studies in brachytherapy compatible with clinical practice. Although the proposed platform was evaluated for prostate cancer, it is equally applicable to other LDR brachytherapy clinical applications. Future extensions will allow its application in high dose rate brachytherapy applications.

  6. The effects of mapping CT images to Monte Carlo materials on GEANT4 proton simulation accuracy

    SciTech Connect

    Barnes, Samuel; McAuley, Grant; Slater, James; Wroe, Andrew

    2013-04-15

    Purpose: Monte Carlo simulations of radiation therapy require conversion from Hounsfield units (HU) in CT images to an exact tissue composition and density. The number of discrete densities (or density bins) used in this mapping affects the simulation accuracy, execution time, and memory usage in GEANT4 and other Monte Carlo code. The relationship between the number of density bins and CT noise was examined in general for all simulations that use HU conversion to density. Additionally, the effect of this on simulation accuracy was examined for proton radiation. Methods: Relative uncertainty from CT noise was compared with uncertainty from density binning to determine an upper limit on the number of density bins required in the presence of CT noise. Error propagation analysis was also performed on continuously slowing down approximation range calculations to determine the proton range uncertainty caused by density binning. These results were verified with Monte Carlo simulations. Results: In the presence of even modest CT noise (5 HU or 0.5%) 450 density bins were found to only cause a 5% increase in the density uncertainty (i.e., 95% of density uncertainty from CT noise, 5% from binning). Larger numbers of density bins are not required as CT noise will prevent increased density accuracy; this applies across all types of Monte Carlo simulations. Examining uncertainty in proton range, only 127 density bins are required for a proton range error of <0.1 mm in most tissue and <0.5 mm in low density tissue (e.g., lung). Conclusions: By considering CT noise and actual range uncertainty, the number of required density bins can be restricted to a very modest 127 depending on the application. Reducing the number of density bins provides large memory and execution time savings in GEANT4 and other Monte Carlo packages.

  7. Geant4-DNA simulations using complex DNA geometries generated by the DnaFabric tool

    NASA Astrophysics Data System (ADS)

    Meylan, S.; Vimont, U.; Incerti, S.; Clairand, I.; Villagrasa, C.

    2016-07-01

    Several DNA representations are used to study radio-induced complex DNA damages depending on the approach and the required level of granularity. Among all approaches, the mechanistic one requires the most resolved DNA models that can go down to atomistic DNA descriptions. The complexity of such DNA models make them hard to modify and adapt in order to take into account different biological conditions. The DnaFabric project was started to provide a tool to generate, visualise and modify such complex DNA models. In the current version of DnaFabric, the models can be exported to the Geant4 code to be used as targets in the Monte Carlo simulation. In this work, the project was used to generate two DNA fibre models corresponding to two DNA compaction levels representing the hetero and the euchromatin. The fibres were imported in a Geant4 application where computations were performed to estimate the influence of the DNA compaction on the amount of calculated DNA damage. The relative difference of the DNA damage computed in the two fibres for the same number of projectiles was found to be constant and equal to 1.3 for the considered primary particles (protons from 300 keV to 50 MeV). However, if only the tracks hitting the DNA target are taken into account, then the relative difference is more important for low energies and decreases to reach zero around 10 MeV. The computations were performed with models that contain up to 18,000 DNA nucleotide pairs. Nevertheless, DnaFabric will be extended to manipulate multi-scale models that go from the molecular to the cellular levels.

  8. Software design studies emphasizing Project LOGOS

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of a research project on the development of computer software are presented. Research funds of $200,000 were expended over a three year period for software design and projects in connection with Project LOGOS (computer-aided design and certification of computing systems). Abstracts of theses prepared during the project are provided.

  9. Dosimetry characterization of 32P intravascular brachytherapy source wires using Monte Carlo codes PENELOPE and GEANT4.

    PubMed

    Torres, Javier; Buades, Manuel J; Almansa, Julio F; Guerrero, Rafael; Lallena, Antonio M

    2004-02-01

    Monte Carlo calculations using the codes PENELOPE and GEANT4 have been performed to characterize the dosimetric parameters of the new 20 mm long catheter-based 32P beta source manufactured by the Guidant Corporation. The dose distribution along the transverse axis and the two-dimensional dose rate table have been calculated. Also, the dose rate at the reference point, the radial dose function, and the anisotropy function were evaluated according to the adapted TG-60 formalism for cylindrical sources. PENELOPE and GEANT4 codes were first verified against previous results corresponding to the old 27 mm Guidant 32P beta source. The dose rate at the reference point for the unsheathed 27 mm source in water was calculated to be 0.215 +/- 0.001 cGy s(-1) mCi(-1), for PENELOPE, and 0.2312 +/- 0.0008 cGy s(-1) mCi(-1), for GEANT4. For the unsheathed 20 mm source, these values were 0.2908 +/- 0.0009 cGy s(-1) mCi(-1) and 0.311 0.001 cGy s(-1) mCi(-1), respectively. Also, a comparison with the limited data available on this new source is shown. We found non-negligible differences between the results obtained with PENELOPE and GEANT4. PMID:15000615

  10. A Geant4 simulation of the depth dose percentage in brain tumors treatments using protons and carbon ions

    NASA Astrophysics Data System (ADS)

    José A. Diaz, M.; Torres, D. A.

    2016-07-01

    The deposited energy and dose distribution of beams of protons and carbon over a head are simulated using the free tool package Geant4 and the data analysis package ROOT-C++. The present work shows a methodology to understand the microscopical process occurring in a session of hadron-therapy using advance simulation tools.