Status and Recent Developments Makoto Asai (SLAC) On Behalf of the Geant4 Collaboration May 26 th, 2007 Third McGill Workshop on Monte Carlo Techniques

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

General introduction General introduction and brief historyand brief history


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.


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


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 – 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 Geant4 CollaborationCollaboration

Collaborators also from non-member institutions, including

Budker Inst. of PhysicsIHEP Protvino

MEPHI Moscow Pittsburg University

Lebedev

TRIUMF

J.W.GoetheUniversität



http://top25.sciencedirect.com/index.php?subject_area_id=21


Beam line and radiation Beam line and radiation protectionprotection


Harald Paganetti

GEANT4 based proton dose calculation in a clinical environment: technical aspects, strategies and challenges


Screen shots of gMocrenScreen shots of gMocren

http://geant4.kek.jp/gMocren/


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)


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



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


LDR 125I source, Amersham 6711

Validation of the model:radial dose function

Prostate brachytherapy - LDRProstate brachytherapy - LDR

J.-F. Carrier, Ph.D. project


Octree geometry compression – DICOM imagesOctree geometry compression – DICOM images

Examples: CT phantom + thorax patient

Voxel number v/s DGT


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

Geant4 licenseGeant4 license

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/


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 [email protected]. 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.


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.


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.


•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/


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)


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.


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.


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;…


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);

}


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.


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.


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


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).


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


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 ?


Result of upgradesResult of upgrades

7.1

8.1


Electron scattering Electron scattering (L.Urban, CERN-OPEN-2006-077, g4 8.2)(L.Urban, CERN-OPEN-2006-077, g4 8.2)


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

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3

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Standard SubCutOff Livermore Penelope Data

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Fraction of a Mean Range(FMR)

Dep

osit

Ene

rgy

(MeV

/g/c

m²)


0

0,5

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Fraction of Mean Range

En

erg

y D

epo

sitio

n (M

eV/g

/cm

²)


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

)


Proton scattering Proton scattering (L.Urban) (L.Urban)

NSS IEEE 2004 Conf.Rec., Vol.3, 1907 CERN-OPEN-2006-077

FWHM of projected angle


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


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


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




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


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)


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

User support processesUser support processes


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 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 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/


HyperNewsHyperNews HyperNews system was set up in April 2001 HyperNews system was set up in April 2001


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/

Documents

Status and Recent Developments Makoto Asai (SLAC) On Behalf of the Geant4 Collaboration May 26 th, 2007 Third McGill Workshop on Monte Carlo Techniques