Post on 15-Dec-2015
Status and Recent Status and Recent DevelopmentsDevelopments
Makoto Asai (SLAC)Makoto Asai (SLAC)
On Behalf of On Behalf of the Geant4 Collaborationthe Geant4 Collaboration
May 26May 26thth, 2007, 2007
Third McGill Workshop on Monte Carlo Third McGill Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Techniques in Radiotherapy Delivery and
VerificationVerification
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 22
ContentsContents General introduction General introduction
and brief historyand brief history
Geant4 licenseGeant4 license
Highlights of recent Highlights of recent
developmentsdevelopments
KernelKernel
EM physicsEM physics
Hadronic physicsHadronic physics
User support User support
processesprocesses
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 44
What is Geant4?What is Geant4? Geant4 is the successor of GEANT3, the world-standard toolkit for HEP Geant4 is the successor of GEANT3, the world-standard toolkit for HEP
detector simulation.detector simulation.
Geant4 is one of the first successful attempt to re-design a major Geant4 is one of the first successful attempt to re-design a major
package of HEP software for the next generation of experiments using package of HEP software for the next generation of experiments using
an Object-Oriented environment. an Object-Oriented environment.
A variety of requirements have also taken into account from heavy ion A variety of requirements have also taken into account from heavy ion
physics, CP violation physics, cosmic ray physics, astrophysics, space physics, CP violation physics, cosmic ray physics, astrophysics, space
science and medical applications. science and medical applications.
In order to meet such requirements, a large degree of functionality In order to meet such requirements, a large degree of functionality
and flexibility are provided.and flexibility are provided.
G4 is not only for HEP but goes well beyond that.G4 is not only for HEP but goes well beyond that.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 55
Flexibility of Geant4Flexibility of Geant4 In order to meet wide variety of requirements from various application In order to meet wide variety of requirements from various application
fields, a large degree of functionality and flexibility are provided. fields, a large degree of functionality and flexibility are provided.
Geant4 has many types of geometrical descriptions to describe most Geant4 has many types of geometrical descriptions to describe most
complicated and realistic geometries complicated and realistic geometries
CSG, BREP and Boolean solidsCSG, BREP and Boolean solids
Placement, replica, divided, parameterized, reflected and groupedPlacement, replica, divided, parameterized, reflected and grouped
XML interfaceXML interface
Everything is open to the user Everything is open to the user
Choice of physics processes/modelsChoice of physics processes/models
Choice of GUI/Visualization/persistency/histogramming Choice of GUI/Visualization/persistency/histogramming
technologiestechnologies
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 66
Physics in Geant4Physics in Geant4 Geant4 offers Geant4 offers
EM processes, EM processes,
Hadronic processes, Hadronic processes,
Photon/lepton-hadron processes, Photon/lepton-hadron processes,
Optical photon processes, Optical photon processes,
Decay processes, Decay processes,
Shower parameterization, Shower parameterization,
Event biasing techniques, and Event biasing techniques, and
you can plug-in moreyou can plug-in more. .
Geant4 provides sets of alternative physics models so that the user can freely Geant4 provides sets of alternative physics models so that the user can freely
choose appropriate models according to the type of his/her application.choose appropriate models according to the type of his/her application.
In other words, it is the user’s responsibility to choose reasonable set of In other words, it is the user’s responsibility to choose reasonable set of
physics processes/models that fits to his/her needs.physics processes/models that fits to his/her needs.
For example, some models are more accurate than others at a sacrifice of For example, some models are more accurate than others at a sacrifice of
speed.speed.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 77
Geant4 – Its historyGeant4 – Its history Dec ’94 - Project startDec ’94 - Project start
Apr ’97 - First alpha release Apr ’97 - First alpha release
Jul ’98 - First beta release Jul ’98 - First beta release
Dec ’98 - First Geant4 public release - version 1.0Dec ’98 - First Geant4 public release - version 1.0
……
June 30June 30thth, ’06 - Geant4 version 8.1 release, ’06 - Geant4 version 8.1 release
July 27July 27thth, ’06 - Geant4 8.1-patch01 release, ’06 - Geant4 8.1-patch01 release
Dec 15Dec 15thth, ’06 - Geant4 version 8.2 release, ’06 - Geant4 version 8.2 release
Feb 23Feb 23rdrd, ’07 - Geant4 8.2-patch01 release, ’07 - Geant4 8.2-patch01 release
May 11May 11thth, ’07 - Geant4 version 8.3 release, ’07 - Geant4 version 8.3 release
June 29June 29thth, ’07 - Geant4 version 9.0 release (planned), ’07 - Geant4 version 9.0 release (planned)
We currently provide two to three public releases every year.We currently provide two to three public releases every year.
Bimonthly beta releases are available to the registered beta-testers.Bimonthly beta releases are available to the registered beta-testers.
Current version
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 88
Geant4 Geant4 CollaborationCollaboration
Collaborators also from non-member institutions, including
Budker Inst. of PhysicsIHEP Protvino
MEPHI Moscow Pittsburg University
Lebedev
TRIUMF
J.W.GoetheUniversität
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 99
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1010
http://top25.sciencedirect.com/index.php?subject_area_id=21
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1111
Beam line and radiation Beam line and radiation protectionprotection
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1212
Harald Paganetti
GEANT4 based proton dose calculation in a clinical environment: technical aspects, strategies and challenges
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1313
Screen shots of gMocrenScreen shots of gMocren
http://geant4.kek.jp/gMocren/
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1414
Modeling of encapsulated Modeling of encapsulated 192192Ir sourceIr source(Courtesy of McGill University)(Courtesy of McGill University)
3.5 mm
5 mm
1.1 mm
2 m
0.6 mm
MicroSelectron Classic HDR source (part no. 080950)
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1515
Hampton UniversityHampton University(Collaboration: Proxima Therapeutics, dePaul)(Collaboration: Proxima Therapeutics, dePaul)
Active Mammosite
→ Absolute real-time position measurement (within ±1 mm)
→ Absolute real-time dose measurement
→ Modelization of the dose distribution using CT scan data
& 4D phantom
Jacquelyn Winston, M.Sc.: Detector
Rachel Black, Ph.D. : Detector, Geant4 & VTK
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1616
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1717
Radial dose and anisotropy functions of Radial dose and anisotropy functions of encapsulated sourceencapsulated source
(Courtesy of McGill University)(Courtesy of McGill University)
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
1.05
0 3 6 9 12 15radial distance (cm)
rad
ial d
os
e f
un
cti
on
g(r
)
GEANT4
Williamson and Li
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
1.05
0 50 100 150angle (degree)
F (
r, t
het
a)
r = 0.25 cm r = 0.5 cm
r = 1 cm r = 2 cm
r = 3 cm r = 5 cm
Radial dose functionGEANT4:~0.4% higher than Williamson and Li (Med. Phys. 22, 809-819, 1995)
Anisotropy functionGEANT4: ±1% agreement with Williamson and Li
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1818
LDR 125I source, Amersham 6711
Validation of the model:radial dose function
Prostate brachytherapy - LDRProstate brachytherapy - LDR
J.-F. Carrier, Ph.D. project
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 1919
Octree geometry compression – DICOM imagesOctree geometry compression – DICOM images
Examples: CT phantom + thorax patient
Voxel number v/s DGT
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 2020
CT-simulation with a Rando phantomExperimental data obtained with TLD LiF dosimeter
CT images used to define the geometry:
a thorax slice from a Rando
anthropomorphic phantom
Comparison with commercial treatment Comparison with commercial treatment planning systemsplanning systems
M. C. Lopes 1, L. Peralta 2, P. Rodrigues 2, A. Trindade 2
1 IPOFG-CROC Coimbra Oncological Regional Center - 2 LIP - Lisbon
Agreement better than 2% between GEANT4 and TLD dosimeters
The New Geant4 License
•Makes clear the user’s Makes clear the user’s wide-ranging freedom to wide-ranging freedom to use, extend or redistribute use, extend or redistribute Geant4, even as part of Geant4, even as part of some for-profit venture.some for-profit venture.
•The license was released The license was released along with the Geant4 along with the Geant4 release 8.1 in June 2006.release 8.1 in June 2006.
•Simple enough that you Simple enough that you can read and understand can read and understand it.it.
In response to user requests for clarification of Geant4’s In response to user requests for clarification of Geant4’s distribution policy, the collaboration recently announced a new distribution policy, the collaboration recently announced a new license.license.
•http://cern.ch/geant4/license/http://cern.ch/geant4/license/
The New Geant4 License
Installation, use, reproduction, display, modification and redistribution of this software, with or without modification, in source and binary forms, are permitted on a non- exclusive basis. Any exercise of rights by you under this license is subject to the following conditions: 1. Redistributions of this software, in whole or in part, with or without modification, must reproduce the above copyright notice and these license conditions in this software, the user documentation and any other materials provided with the redistributed software. 2. The user documentation, if any, included with a redistribution, must include the following notice:"This product includes software developed by Members of the Geant4 Collaboration ( http://cern.ch/geant4 )." If that is where third-party acknowledgments normally appear, this acknowledgment must be reproduced in the modified version of this software itself. 3. The names "Geant4” and “The Geant4 toolkit” may not be used to endorse or promote software, or products derived therefrom, except with prior written permission by license@geant4.org. If this software is redistributed in modified form, the name and reference of the modified version must be clearly distinguishable from that of this software.
License has 8 points. The points are written clearly and simply.License has 8 points. The points are written clearly and simply.
1,2 and 3) tell the world who the software came from, and don’t claim 1,2 and 3) tell the world who the software came from, and don’t claim you are us.you are us.
The New Geant4 License
4. You are under no obligation to provide anyone with any modifications of this software that you may develop, including but not limited to bug fixes, patches, upgrades or other enhancements or derivatives of the features, functionality or performance of this software. However, if you publish or distribute your modifications without contemporaneously requiring users to enter into a separate written license agreement, then you are deemed to have granted all Members and all Copyright Holders of the Geant4 Collaboration a license to your modifications, including modifications protected by any patent owned by you, under the conditions of this license. 5. You may not include this software in whole or in part in any patent or patent application in respect of any modification of this software developed by you.
4) If you choose to give it away free to everyone, we can have it for 4) If you choose to give it away free to everyone, we can have it for free too.free too.
5) You can’t patent the parts we did.5) You can’t patent the parts we did.
The New Geant4 License
6. DISCLAIMERTHIS SOFTWARE IS PROVIDED BY THE MEMBERS AND COPYRIGHT HOLDERS OF THE GEANT4 COLLABORATION AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY, OF SATISFACTORY QUALITY, AND FITNESS FOR A PARTICULAR PURPOSE OR USE ARE DISCLAIMED. THE MEMBERS OF THE GEANT4 COLLABORATION AND CONTRIBUTORS MAKE NO REPRESENTATION THAT THE SOFTWARE AND MODIFICATIONS THEREOF, WILL NOT INFRINGE ANY PATENT, COPYRIGHT, TRADE SECRET OR OTHER PROPRIETARY RIGHT. 7. LIMITATION OF LIABILITYTHE MEMBERS AND COPYRIGHT HOLDERS OF THE GEANT4 COLLABORATION AND CONTRIBUTORS SHALL HAVE NO LIABILITY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES OF ANY CHARACTER INCLUDING, WITHOUT LIMITATION, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF USE, DATA OR PROFITS, OR BUSINESS INTERRUPTION, HOWEVER CAUSED AND ON ANY THEORY OF CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCT LIABILITY OR OTHERWISE, ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 8. This license shall terminate with immediate effect and without notice if you fail to comply with any of the terms of this license, or if you institute litigation against any Member or Copyright Holder of the Geant4 Collaboration with regard to this software.
We don’t claim that it works, and we’re not responsible if it doesn’t.We don’t claim that it works, and we’re not responsible if it doesn’t.
The New Geant4 License
•Through the generous Through the generous support of many support of many governments and governments and institutions, you, the institutions, you, the community, have already community, have already paid for Geant4.paid for Geant4.
•We, the Geant4 We, the Geant4 collaboration, want you to collaboration, want you to enjoy the software and enjoy the software and use it where ever you can.use it where ever you can.
That’s it.That’s it.
•http://cern.ch/geant4/license/http://cern.ch/geant4/license/
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 2727
Highlights of recent Highlights of recent developmentsdevelopments
- kernel - - kernel -
Scorer and filter classesScorer and filter classes Nested parameterizationNested parameterization Parallel navigationParallel navigation Event biasing (variance Event biasing (variance
reduction)reduction)
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 2828
Sensitive detector vs. primitive Sensitive detector vs. primitive scorerscorer
Sensitive detectorSensitive detector You have to implement your You have to implement your
own detector and hit classes.own detector and hit classes. One hit class can contain many One hit class can contain many
quantities. A hit can be made quantities. A hit can be made for each individual step, or for each individual step, or accumulate quantities.accumulate quantities.
Basically one hits collection is Basically one hits collection is made per one detector.made per one detector.
Hits collection is relatively Hits collection is relatively compact. compact.
Primitive scorerPrimitive scorer Many scorers are provided by Many scorers are provided by
Geant4. You can add your own.Geant4. You can add your own. Each scorer accumulates one Each scorer accumulates one
quantity for an event. quantity for an event.
G4MultiFunctionalDetector G4MultiFunctionalDetector creates many collections creates many collections (maps), i.e. one collection per (maps), i.e. one collection per one scorer.one scorer.
Keys of maps are redundant for Keys of maps are redundant for scorers of same volume.scorers of same volume.
I would suggest to :I would suggest to : Use primitive scorers Use primitive scorers
if you are if you are notnot interested in recording each individual step interested in recording each individual step butbut accumulating some physics quantities for an event or a run, andaccumulating some physics quantities for an event or a run, and
if you do if you do notnot have to have too many scorers. have to have too many scorers. Otherwise, consider implementing your own sensitive detector.Otherwise, consider implementing your own sensitive detector.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 2929
List of provided primitive scorersList of provided primitive scorers Concrete Primitive Scorers ( See Application Developers Guide 4.4.6 )Concrete Primitive Scorers ( See Application Developers Guide 4.4.6 )
Track lengthTrack length G4PSTrackLength, G4PSPassageTrackLengthG4PSTrackLength, G4PSPassageTrackLength
Deposited energyDeposited energy G4PSEnergyDepsit, G4PSDoseDeposit, G4PSChargeDepositG4PSEnergyDepsit, G4PSDoseDeposit, G4PSChargeDeposit
Current/FluxCurrent/Flux G4PSFlatSurfaceCurrent, G4PSFlatSurfaceCurrent,
G4PSSphereSurfaceCurrent,G4PSPassageCurrent, G4PSFlatSurfaceFlux, G4PSSphereSurfaceCurrent,G4PSPassageCurrent, G4PSFlatSurfaceFlux, G4PSCellFlux, G4PSPassageCellFluxG4PSCellFlux, G4PSPassageCellFlux
OthersOthers G4PSMinKinEAtGeneration, G4PSNofSecondary, G4PSNofStepG4PSMinKinEAtGeneration, G4PSNofSecondary, G4PSNofStep
angle
V : Volume
L : Total step length in the cell.
SurfaceCurrentSurfaceCurrent ::
Count Count number of number of injecting injecting particles particles at defined at defined surface.surface.
SurfaceFluxSurfaceFlux : :Sum up Sum up 1/cos(angle) of 1/cos(angle) of injecting injecting particlesparticlesat defined at defined surfacesurface
CellFluxCellFlux : :Sum of L / V of Sum of L / V of injecting particles injecting particles in the geometrical in the geometrical cell.cell.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3030
List of provided filter classesList of provided filter classes G4SDChargedFilter, G4SDNeutralFilterG4SDChargedFilter, G4SDNeutralFilter
Accept only charged/neutral tracks, respectivelyAccept only charged/neutral tracks, respectively G4SDKineticEnergyFilterG4SDKineticEnergyFilter
Accepts tracks within the defined range of kinetic energyAccepts tracks within the defined range of kinetic energy G4SDParticleFilterG4SDParticleFilter
Accepts tracks of registered particle typesAccepts tracks of registered particle types G4SDParticleWithEnergyFilterG4SDParticleWithEnergyFilter
Accepts tracks of registered particle types within the defined range Accepts tracks of registered particle types within the defined range of kinetic energyof kinetic energy
G4VSDFilterG4VSDFilter Abstract base class which you can use to make your own filterAbstract base class which you can use to make your own filterclass G4VSDFilter { public: G4VSDFilter(G4String name); virtual ~G4VSDFilter(); public: virtual G4bool Accept(const G4Step*) const = 0;…
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3131
For example…For example…MyDetectorConstruction::Construct()
{ … G4LogicalVolume* myCellLog = new G4LogicalVolume(…);
G4VPhysicalVolume* myCellPhys = new G4PVParametrised(…);
G4MultiFunctionalDetector* myScorer = new G4MultiFunctionalDetector(“myCellScorer”);
G4SDManager::GetSDMpointer()->AddNewDetector(myScorer);
myCellLog->SetSensitiveDetector(myScorer);
G4VPrimitiveSensitivity* totalSurfFlux = new G4PSFlatSurfaceFlux(“TotalSurfFlux”);
myScorer->Register(totalSurfFlux);
G4VPrimitiveSensitivity* protonSufFlux = new G4PSFlatSurfaceFlux(“ProtonSurfFlux”);
G4VSDFilter* protonFilter = new G4SDParticleFilter(“protonFilter”);
protonFilter->Add(“proton”);
protonSurfFlux->SetFilter(protonFilter);
myScorer->Register(protonSurfFlux);
}
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3232
Nested parameterizationNested parameterization Suppose your geometry has three-dimensional regular reputation of
same shape and size of volumes without gap between volumes. And material of such volumes are changing according to the position.
E.g. voxels made by CT Scan data (DICOM) Instead of direct three-dimensional parameterized volume,
use replicas for the first and second axes sequentially, and then use one-dimensional parameterization along the third axis.
It requires much less memory for geometry optimization and gives much faster navigation for ultra-large number of voxels.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3333
Parallel navigationParallel navigation Occasionally, it is not straightforward to define sensitivity, importance Occasionally, it is not straightforward to define sensitivity, importance
or envelope to be assigned to volumes in the mass geometry.or envelope to be assigned to volumes in the mass geometry. Typically a geometry built machinery by CAD, GDML, DICOM, etc. Typically a geometry built machinery by CAD, GDML, DICOM, etc.
has this difficulty.has this difficulty. New parallel navigation functionality allows the user to define more New parallel navigation functionality allows the user to define more
than one worlds simultaneously.than one worlds simultaneously. New G4Transportation process sees all worlds simultaneously.New G4Transportation process sees all worlds simultaneously. A step is limited not only by the boundary of the mass geometry A step is limited not only by the boundary of the mass geometry
but also by the boundaries of parallel geometries. but also by the boundaries of parallel geometries. Materials, production thresholds and EM field are used only from Materials, production thresholds and EM field are used only from
the mass geometry.the mass geometry. In a parallel world, the user can define volumes in arbitrary In a parallel world, the user can define volumes in arbitrary
manner with sensitivity, regions with shower parameterization, manner with sensitivity, regions with shower parameterization,
and/or importance field for biasing. and/or importance field for biasing. Volumes in different worlds may overlap.Volumes in different worlds may overlap.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3434
New exampleN07New exampleN07 Mass geometryMass geometry
sandwich of sandwich of rectangular rectangular absorbers and absorbers and scintilatorsscintilators
Parallel scoring Parallel scoring geometrygeometry Cylindrical layersCylindrical layers
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3535
Moving objectsMoving objects In some applications, it is essential to simulate the movement of In some applications, it is essential to simulate the movement of
some volumes.some volumes.
E.g. particle therapy simulationE.g. particle therapy simulation
Geant4 can deal with moving volumeGeant4 can deal with moving volume
In case speed of the moving volume is slow enough compared to In case speed of the moving volume is slow enough compared to
speed of elementary particles, so that you can assume the speed of elementary particles, so that you can assume the
position of moving volume is still within one event.position of moving volume is still within one event.
Two tips to simulate moving objects :Two tips to simulate moving objects :
1.1. Use parameterized volume to represent the moving volume.Use parameterized volume to represent the moving volume.
2.2. Do not optimize (voxelize) the mother volume of the moving Do not optimize (voxelize) the mother volume of the moving
volume(s).volume(s).
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3636
Highlights of recent Highlights of recent developmentsdevelopments- EM physics - - EM physics -
Revised multiple scattering algorithmRevised multiple scattering algorithmand a new single scattering processand a new single scattering process
Refinements in energy loss processRefinements in energy loss process Compton scattering - extended energy Compton scattering - extended energy
rangerange PolarizationPolarization Very low energy extensionVery low energy extension
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3737
New multiple scatteringNew multiple scattering Step limit defined at first step and reevaluated after a boundaryStep limit defined at first step and reevaluated after a boundary
applied only if range > safetyapplied only if range > safety step =step = fr fr . max (range, . max (range, ))
new default fr = new default fr = 0.020.02 (instead of 0.2) (instead of 0.2) strong constraint only for low energy particlesstrong constraint only for low energy particles
ensure that a track always ensure that a track always goes few steps in any volumegoes few steps in any volume (at least 3) (at least 3) step limit min becomes material dependant, via step limit min becomes material dependant, via λλ : :
step limit min = max (0.04 step limit min = max (0.04 λλ, 5 nm) , 5 nm) Re-evaluate safety radius before to perform lateral displacement Re-evaluate safety radius before to perform lateral displacement
d < safety (d < safety (safety is often underestimatedsafety is often underestimated)) Correlate final direction with lateral displacementCorrelate final direction with lateral displacement
uu∙∙d = f (d = f () taken from Lewis theory) taken from Lewis theory Angular distribution : both central part and tail slightly modifiedAngular distribution : both central part and tail slightly modified Single Coulomb scattering at boundariesSingle Coulomb scattering at boundaries
1 very small step (~ 1 very small step (~ elastic) before boundary crossing elastic) before boundary crossing apply approximate single Coulomb scattering in this stepapply approximate single Coulomb scattering in this step
reduce artifact step size dependence ?reduce artifact step size dependence ?
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3838
Result of upgradesResult of upgrades
7.1
8.1
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 3939
Electron scattering Electron scattering (L.Urban, CERN-OPEN-2006-077, g4 8.2)(L.Urban, CERN-OPEN-2006-077, g4 8.2)
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4040
Electron energy deposition in semi-infinite Electron energy deposition in semi-infinite media (Sandia data, g4 8.1)media (Sandia data, g4 8.1)
(O.Kadri, 11(O.Kadri, 11thth Geant4 workshop, Lisbon, 2006) Geant4 workshop, Lisbon, 2006)
0.521 MeV e- in Al
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
0 0,2 0,4 0,6 0,8 1 1,2
Fraction of a Mean Range(FMR)
En
erg
y D
epo
sit
(MeV
/g/c
m²)
Standard SubCutOff Livermore Penelope Data 0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
0 0,1 0,2 0,3 0,4 0,5 0,6
Standard SubCutOff Livermore Penelope Data
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
Fraction of a Mean Range(FMR)
Dep
osit
Ene
rgy
(MeV
/g/c
m²)
Standard SubCutOff Livermore Penelope Data
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8
Fraction of Mean Range
En
erg
y D
epo
sitio
n (M
eV/g
/cm
²)
Standard SubCutOff Livermore Penelope Data
Al Au Al
0.521 MeV e- in Al 0.5 MeV e- in Ta
Ta
Al
4 configurations of EM physics, standard cuts and step limits
Max diff15%
Energy deposition precision better 3%; deviation in peak less than 10%
R/R0
Dose
(M
eV
/mm
)
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4141
Proton scattering Proton scattering (L.Urban) (L.Urban)
NSS IEEE 2004 Conf.Rec., Vol.3, 1907 CERN-OPEN-2006-077
FWHM of projected angle
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4242
Proton and ion stopping in waterProton and ion stopping in water(QBBC Physics List)(QBBC Physics List)
A.Bagulya et al., 11th Geant4 workshop, Lisbon, 2006
Dose deposition normalized to peak
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4343
Stopping powers of protons in Standard Stopping powers of protons in Standard EM package in comparison with EM package in comparison with
evaluated dataevaluated data (A.Ivantchenko, V.Ivanchenko, 11th Geant4 workshop, Lisbon, 2006)(A.Ivantchenko, V.Ivanchenko, 11th Geant4 workshop, Lisbon, 2006)
NIST – 8.1ICRU – 7.1
Precision of evaluated data about 2% above 1 MeV and less below
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4444
Comments on stopping powers Comments on stopping powers SRIM-2006 claims the systematic uncertainty better 5 %SRIM-2006 claims the systematic uncertainty better 5 % NIST claims the systematic uncertainty:NIST claims the systematic uncertainty:
2 % at high energies2 % at high energies 5 % at 1 MeV5 % at 1 MeV 10 % at 10 – 100 keV10 % at 10 – 100 keV 20 % below 10 keV20 % below 10 keV
Geant4 stopping power is material dependent:Geant4 stopping power is material dependent: NIST materialsNIST materials allows to use the precise parameterization of allows to use the precise parameterization of
stopping powers, which agrees both with NIST and SRIM’06stopping powers, which agrees both with NIST and SRIM’06 Hand-typed materialsHand-typed materials – ICRU parameterization – ICRU parameterization
Different level of agreement between NIST/ICRU/SRIM for 8.1Different level of agreement between NIST/ICRU/SRIM for 8.1 E > 10 MeV - 2%E > 10 MeV - 2% 0.5 MeV < E < 10 MeV – 5%0.5 MeV < E < 10 MeV – 5% E < 0.5 MeV – 20% for some materials much betterE < 0.5 MeV – 20% for some materials much better Better agreement for pure materialsBetter agreement for pure materials
All parameterizations are within uncertaintyAll parameterizations are within uncertainty
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4545
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4646
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4747
Highlights of recent Highlights of recent developmentsdevelopments
- Hadronic physics - - Hadronic physics -
Isotope dependencyIsotope dependency High precision neutron High precision neutron
processprocess New elastic scatteringNew elastic scattering
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4848
Isotope Dependence and Neutron Isotope Dependence and Neutron HPHP
Isotope dependenceIsotope dependence
Users have always been able to build “custom” elements by Users have always been able to build “custom” elements by
choosing a specific combination of isotopeschoosing a specific combination of isotopes
the electromagnetic code respected this choicethe electromagnetic code respected this choice
the hadronic code ignored it, using instead natural abundances the hadronic code ignored it, using instead natural abundances
In Geant4 8.3 the hadronic code now properly calculates cross In Geant4 8.3 the hadronic code now properly calculates cross
sections based on the user-defined isotope choice sections based on the user-defined isotope choice
High precision neutronHigh precision neutron
High precision neutron code models capture, fission, elastic and High precision neutron code models capture, fission, elastic and
inelastic neutron interactions for 20 MeV down to thermal energiesinelastic neutron interactions for 20 MeV down to thermal energies
depends on G4NDL database of cross sections and final state depends on G4NDL database of cross sections and final state
informationinformation
this list is rather large, but still not complete (some isotopic this list is rather large, but still not complete (some isotopic
data is missing)data is missing)
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 4949
Elastic ScatteringElastic Scattering Continuous improvement of elastic scattering models since Geant4 7.1Continuous improvement of elastic scattering models since Geant4 7.1
The old GHEISHA-style model G4LElastic used non-relativistic scattering The old GHEISHA-style model G4LElastic used non-relativistic scattering and parameterized the interactions based on thatand parameterized the interactions based on that
New relativistically correct model now available but should not be used New relativistically correct model now available but should not be used with the LHEP-based physics lists (upsets the parameterization)with the LHEP-based physics lists (upsets the parameterization)
A new unified elastic process, model and cross section data set are now A new unified elastic process, model and cross section data set are now available for physics lists other than LHEP-based (QGSP, etc.)available for physics lists other than LHEP-based (QGSP, etc.)
G4UHadronElasticProcessG4UHadronElasticProcess the new elastic scattering process which uses CHIPS the new elastic scattering process which uses CHIPS
parameterized cross sections (see below) for p, n incident on H parameterized cross sections (see below) for p, n incident on H and Heand He
all other particles use original GHEISHA cross sectionsall other particles use original GHEISHA cross sections good for all long-lived hadrons, deuterons, tritons, alphasgood for all long-lived hadrons, deuterons, tritons, alphas
G4HadronElasticG4HadronElastic a new elastic scattering model which uses coherent elastic a new elastic scattering model which uses coherent elastic
scattering at high energies (> 1 GeV)scattering at high energies (> 1 GeV) G4QElasticCrossSectionG4QElasticCrossSection
new hadron elastic cross section data set based on the CHIPS new hadron elastic cross section data set based on the CHIPS (chiral invariant phase space) parameterization of cross section (chiral invariant phase space) parameterization of cross section datadata
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 5151
User SupportUser Support Geant4 Collaboration offers extensive user supports. Geant4 Collaboration offers extensive user supports.
Users workshopsUsers workshops
Tutorial coursesTutorial courses
HyperNews and mailing listHyperNews and mailing list
Bug reporting system Bug reporting system
Requirements tracking systemRequirements tracking system
Daily “private” communicationsDaily “private” communications
Technical ForumTechnical Forum
http://cern.ch/geant4/http://cern.ch/geant4/
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 5252
Geant4 users workshopGeant4 users workshop Users workshops were held or are going to be held hosted by several Users workshops were held or are going to be held hosted by several
institutes for various user communities.institutes for various user communities.
KEK - Dec.2000, Jul.2001, Mar.2002, Jul.2002, Mar.2003, Jul.2003, KEK - Dec.2000, Jul.2001, Mar.2002, Jul.2002, Mar.2003, Jul.2003,
Jul.2004, Jan.2005, Jan.2006Jul.2004, Jan.2005, Jan.2006
SLAC - Feb.2002SLAC - Feb.2002
Spain (supported by INFN) - Jul.2002Spain (supported by INFN) - Jul.2002
CERN - Nov.2002CERN - Nov.2002
NASA/ESA/Vanderbilt - Jan.2003, May.2004, Mar.2005, Oct.2005, NASA/ESA/Vanderbilt - Jan.2003, May.2004, Mar.2005, Oct.2005,
Nov.2006Nov.2006
Helsinki - Oct.2003, Jun.2005Helsinki - Oct.2003, Jun.2005
Bordeaux - Nov.2005Bordeaux - Nov.2005
Hebden Bridge (U.K.) - Sep.2007Hebden Bridge (U.K.) - Sep.2007
Local workshops of one or two days were held or are planned at Local workshops of one or two days were held or are planned at
several places. Refer to our web site.several places. Refer to our web site.
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 5353
Geant4 tutorials / lecturesGeant4 tutorials / lectures In addition to the users workshops, many tutorial courses and In addition to the users workshops, many tutorial courses and
lectures with some discussion time slots were held for various user lectures with some discussion time slots were held for various user communities.communities. CERN School of ComputingCERN School of Computing Italian National School for HEP/Nuclear PhysicistsItalian National School for HEP/Nuclear Physicists MC2000MC2000 MCNEG workshopMCNEG workshop IEEE NSS/MIC IEEE NSS/MIC KEK, SLAC, DESY, FNAL, INFN, Frascati, Karolinska, GranSasso, KEK, SLAC, DESY, FNAL, INFN, Frascati, Karolinska, GranSasso,
etc.etc. ATLAS, CMS, LHCbATLAS, CMS, LHCb Tutorials/lectures at universitiesTutorials/lectures at universities
Italy - Genoa, Bologna, Udine, Roma, Trieste, …Italy - Genoa, Bologna, Udine, Roma, Trieste, … U.K. - ImperialU.K. - Imperial U.S./Canada – Vanderbilt, McGillU.S./Canada – Vanderbilt, McGill
Geant4 collaboration is happy to offer tutorial courses if requested.Geant4 collaboration is happy to offer tutorial courses if requested. SLAC Geant4 team is offering tutorial courses regularly.SLAC Geant4 team is offering tutorial courses regularly.
http://geant4.slac.stanford.edu/http://geant4.slac.stanford.edu/
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 5454
HyperNewsHyperNews HyperNews system was set up in April 2001 HyperNews system was set up in April 2001
Geant4 - Status and Recent Developments M.Asai (SLAC)Geant4 - Status and Recent Developments M.Asai (SLAC) 5555
HyperNewsHyperNews 24 categories 24 categories Not only “user-developer”, Not only “user-developer”,
but also “user-user” but also “user-user”
information exchanges are information exchanges are
quite intensive.quite intensive.
Geant4 North American Medical Users Organization - G4NAMU
•Bring this community Bring this community together to share issues together to share issues and advice, to develop and advice, to develop regional collaboration and regional collaboration and to communicate as a to communicate as a group to the Geant4 group to the Geant4 developers.developers.
•Current membership Current membership includes 79 members from includes 79 members from 37 institutions throughout 37 institutions throughout Canada and the United Canada and the United StatesStates
Launched in May of 2005 to provide a meeting place for the rapidly Launched in May of 2005 to provide a meeting place for the rapidly growing Geant4 medical user community of North Americagrowing Geant4 medical user community of North America
•http://geant4.slac.stanford.edu/g4namu/http://geant4.slac.stanford.edu/g4namu/