Geant4 Release 8.0 Highlights J. Apostolakis for G4.

Geant4 Release 8.0 Geant4 Release 8.0 HighlightsHighlights

J. Apostolakis for G4J. Apostolakis for G4

Feb 7th, 2006 12th Geant4 Technical Forum 2

OutlineOutline

► Improvements in electron transportImprovements in electron transport Multiple scatteringMultiple scattering

►Developments in kernelDevelopments in kernel Geometry, particlesGeometry, particles

►Refinements, improvements in hadronicsRefinements, improvements in hadronics

► Complete list of scheduled features Complete list of scheduled features http://geant4.web.cern.ch/geant4/source/planned_features.hthttp://geant4.web.cern.ch/geant4/source/planned_features.ht

mlml► Apologies for missing items and missing attributionsApologies for missing items and missing attributions


Review on Multiple Review on Multiple ScatteringScattering

► Simulating energy deposition for thin layers Simulating energy deposition for thin layers precisely has required using very small cuts precisely has required using very small cuts (slow)(slow) medical applications, shielding, fine granular medical applications, shielding, fine granular

calorimeters…calorimeters…

► Users reported results that depended Users reported results that depended significantly on step limits and cut valuesignificantly on step limits and cut value

► An extensive An extensive investigationinvestigation of cut/step limit of cut/step limit effects was carried out, and concluded that: effects was carried out, and concluded that:

Multiple Scattering process is very importantMultiple Scattering process is very importantM. Maire, L. UrbanM. Maire, L. Urban


Upgrade of Multiple Scattering Upgrade of Multiple Scattering between 7.1 and 8.0between 7.1 and 8.0

► Multiple Scattering process Multiple Scattering process (MSC) performs these (MSC) performs these functions:functions: samplessamples scattering angle scattering angle

after stepafter step SamplesSamples laterallateral

displacement displacement t <-> z transformationst <-> z transformations

► Physical <-> geometrical Physical <-> geometrical stepstep

Step limitationStep limitation► G4MscModel G4MscModel ImprovementsImprovements::

Introduced Introduced correlationcorrelation between scattering angle between scattering angle and radial displacementand radial displacement

More precise calculation of More precise calculation of geometry ‘geometry ‘safetysafety’ before ’ before sampling the sampling the displacementdisplacement

► G4MultipleScattering updates:G4MultipleScattering updates: step restriction not only after step restriction not only after

boundary with parameter boundary with parameter facrange but also from facrange but also from the start of the track and from the start of the track and from geometry (facgeom)geometry (facgeom)

► Default values:Default values: facrange = 0.02 facrange = 0.02 facgeom = 4facgeom = 4

► Defaults guarantees, at leastDefaults guarantees, at least 2 steps 2 steps in the start volumein the start volume 4 steps 4 steps in other volumes it in other volumes it

crosses, crosses, ► New method overrides changsNew method overrides changs

► Restores values/results of 7.1Restores values/results of 7.1► SetMscStepLimitation(false) SetMscStepLimitation(false)

In G4VMultipleScatteringIn G4VMultipleScatteringFor further information please see M. Maire’s For further information please see M. Maire’s

talk talk http://agenda.cern.ch/fullAgenda.php?http://agenda.cern.ch/fullAgenda.php?ida=a057572ida=a057572

M. Maire, L. M. Maire, L. UrbanUrban

512th Geant4 Technical ForumFeb 7th, 2006

Motivation/First results of Motivation/First results of UpgradesUpgrades

ZZ

M. Maire, L. UrbanM. Maire, L. Urban


Atlas HEC : CuAtlas HEC : Cu(25mm)(25mm)-lAr-lAr(8.5mm)(8.5mm)

Energy Deposited (GeV)Energy Deposited (GeV) RMS/ (E * sqrt(ERMS/ (E * sqrt(E00/GeV) (%)/GeV) (%)


LHCb : PbLHCb : Pb(2mm)(2mm)-Sc-Sc(4mm)(4mm)


Geometry: Geometry: solids and dynamical solids and dynamical geometriesgeometries

► Additional solidsAdditional solids Generic twisted trapezoid shape with different endcaps - (Generic twisted trapezoid shape with different endcaps - (O. LinkO. Link) ) New ellipsoid (New ellipsoid (G.Guerrieri, INFN/GenovaG.Guerrieri, INFN/Genova) and elliptical cone () and elliptical cone (D. Anninos, D. Anninos,

CERN/CornellCERN/Cornell)) Tetrahedron Tetrahedron (M. Mendelhall, Vanderbilt Univ.)(M. Mendelhall, Vanderbilt Univ.)

► Testing and Improvements Testing and Improvements (O. Link, CERN)(O. Link, CERN) Solid accuracy tests identified problems in torus, sphere (theta)Solid accuracy tests identified problems in torus, sphere (theta) Fix in sphere and improvement of torus (new polynomial solver) Fix in sphere and improvement of torus (new polynomial solver)

► Localized re-optimization for dynamic geometriesLocalized re-optimization for dynamic geometries Change and re-optimize only part of a large geometry (G. Cosmo)Change and re-optimize only part of a large geometry (G. Cosmo)

► Enables lightweight initialisation for changes in dynamic geometriesEnables lightweight initialisation for changes in dynamic geometries


Other new features in Other new features in geometrygeometry

► Overlap detection at construction time Overlap detection at construction time

When a When a volumevolume is placed it is checked optionally for ‘ is placed it is checked optionally for ‘overlapsoverlaps’’

► If it overlaps sister volumes or protrudes from its motherIf it overlaps sister volumes or protrudes from its mother

► Points on its surface are sampled Points on its surface are sampled

► An exception is generated if a point is outside the mother or inside a sister An exception is generated if a point is outside the mother or inside a sister

volumevolume

Applicable for placement and parameterised volumes Applicable for placement and parameterised volumes

► Extended use of Extended use of G4RegionG4Region: :

Was used for G4ProductionCuts and Was used for G4ProductionCuts and

G4VUserRegionInformation, G4VUserRegionInformation,

Can now create Can now create User LimitsUser Limits for Regions (7.1) for Regions (7.1)

Now enabled its use with parameterisation / Fast Simulation Now enabled its use with parameterisation / Fast Simulation

► All these data members are optionalAll these data members are optional


Nested parameterizationNested parameterization► In the past G4VPVParameterization::ComputeMaterial() method used to In the past G4VPVParameterization::ComputeMaterial() method used to

take only the copy number of the immediate physical volumetake only the copy number of the immediate physical volume

There was no way to get a copy number of its (grand)mother volumeThere was no way to get a copy number of its (grand)mother volume

► To implement boxes in 3-Dimensional alignment with varying material To implement boxes in 3-Dimensional alignment with varying material

(e.g. DICOM), one parameterization has to take care of three dimensions.(e.g. DICOM), one parameterization has to take care of three dimensions.

One big mother volume filled by one tiny cell with 3-dimensional One big mother volume filled by one tiny cell with 3-dimensional

parameterizationparameterization

► With newly introducing nested parameterization, a touchable instead of With newly introducing nested parameterization, a touchable instead of

naïve copy number is provided to ComputeMaterial() method.naïve copy number is provided to ComputeMaterial() method.

Material of a box can be indexed not only with the copy number of Material of a box can be indexed not only with the copy number of

the immediate volume but also with copy numbers of its the immediate volume but also with copy numbers of its

(grand)mother volumes(grand)mother volumes

The big mother box can be replicated twice in first and second axes, The big mother box can be replicated twice in first and second axes,

and then parameterized only along the third axis.and then parameterized only along the third axis.

Performance improvement in both voxelization and Performance improvement in both voxelization and

navigation/trackingnavigation/tracking


Non-static particle definitionNon-static particle definition► In Geant4 8.0, all particle definition class objects are instantiated In Geant4 8.0, all particle definition class objects are instantiated

when GenerateParticle() method of physics list is invokedwhen GenerateParticle() method of physics list is invoked Until now, most particle definition objects were static and the Until now, most particle definition objects were static and the

GenerateParticle() method ensured they were linked in the GenerateParticle() method ensured they were linked in the executableexecutable

► A side effect is foreseen if your physics list has physics A side effect is foreseen if your physics list has physics processes/models as data members of your physics lists.processes/models as data members of your physics lists. such processes or models may not been instantiated properly.such processes or models may not been instantiated properly.

► Released revised physics lists to address thisReleased revised physics lists to address this► What to doWhat to do

In case processes/models are defined as data members, they are In case processes/models are defined as data members, they are actually instantiated at the moment your physics list itself is actually instantiated at the moment your physics list itself is instantiated, i.e. before GenerateParticle() method is invoked.instantiated, i.e. before GenerateParticle() method is invoked.

If you use your own copy/customized physics list you will need to If you use your own copy/customized physics list you will need to migratemigrate► For example if you derived from one of the “educated guess” physics For example if you derived from one of the “educated guess” physics

list,list,► How to do thisHow to do this

define pointers for such processes/models as the data members, and make define pointers for such processes/models as the data members, and make sure all processes/models are actually instantiated in your sure all processes/models are actually instantiated in your GenerateProcess() method.GenerateProcess() method.


Concrete sensitivity Concrete sensitivity classesclasses

► Till now Geant4 provided only an Till now Geant4 provided only an abstract classabstract class (G4VSensitiveDetector) (G4VSensitiveDetector)

for the user to define his/her detector sensitivity.for the user to define his/her detector sensitivity.

Various example detector classes are provided.Various example detector classes are provided.

► Good to store Good to store hitshits in their detectors (HEP experiments). in their detectors (HEP experiments).

But is not convenient for radiation applications (Space/medical/HEP)But is not convenient for radiation applications (Space/medical/HEP)

► Where the main interest is Where the main interest is scoring dose/fluxdose/flux..

► G4 8.0 introduces G4MultiFunctionalDetector (a G4VSensitiveDetector). G4 8.0 introduces G4MultiFunctionalDetector (a G4VSensitiveDetector).

In it you can register concrete ‘scorers’ of G4VPrimitiveSensitivity to In it you can register concrete ‘scorers’ of G4VPrimitiveSensitivity to

build a scoring detector as you need.build a scoring detector as you need.

G4PSEnergyDepositionScorer, G4PSSurfaceFluxScorer, G4PSEnergyDepositionScorer, G4PSSurfaceFluxScorer,

G4PSDoseScorer, G4PSTrackLengthScorer, etc. (class names are G4PSDoseScorer, G4PSTrackLengthScorer, etc. (class names are

preliminary) will be provided.preliminary) will be provided.► We will continue working for additional primitive sensitivity concrete We will continue working for additional primitive sensitivity concrete

classes.classes.

M. Asai for Run-Event WGM. Asai for Run-Event WG


Bertini CascadeBertini Cascade► Isotope productionIsotope production

Proton and neutron induced Proton and neutron induced ►Elastic scattering interface for release Elastic scattering interface for release

7.27.2 G4CascadeElasticInterface (for < 1 GeV)G4CascadeElasticInterface (for < 1 GeV)

►Kaon extensionsKaon extensions►ValidationValidation►Optimization for speed, model tuningOptimization for speed, model tuning

A. Heikkinen, D. WrightA. Heikkinen, D. Wright


New Developments in CHIPSNew Developments in CHIPS

►G4QCaptureAtRest for nuclear capture of G4QCaptureAtRest for nuclear capture of negative hadrons, muons, and low energy negative hadrons, muons, and low energy neutrons/antineutrons.neutrons/antineutrons.

► Process level tests for comparison of simulated Process level tests for comparison of simulated parameters with experimental dataparameters with experimental data Validation tests for at rest and in-flight Validation tests for at rest and in-flight

(test19/test29).(test19/test29).►G4QCollision for photo- and lepto-nuclear G4QCollision for photo- and lepto-nuclear

reactionsreactions with DIS simulation of neutrino-nuclear reactions.with DIS simulation of neutrino-nuclear reactions.

► New fixed version of CHIPS for QGSC and FTFC.New fixed version of CHIPS for QGSC and FTFC.

M. KosovM. Kosov


Neutrino-nuclear interactions for Neutrino-nuclear interactions for CNGSCNGS


Physics ListsPhysics Lists

► Revised to work with Geant4 8.0Revised to work with Geant4 8.0 Co-work with particles revisionCo-work with particles revision

► Utilise EM(std) physics buildersUtilise EM(std) physics builders Tested by EM(std) WG on HEP calorimeter setupsTested by EM(std) WG on HEP calorimeter setups

► Now Now -A interactions is default in all PLs-A interactions is default in all PLs QGSP_GN is now QGSP, includesQGSP_GN is now QGSP, includesnuclearnuclear A few ‘engines’ suppressed A few ‘engines’ suppressed

►LHEP_GN, ..LHEP_GN, ..

► New variant with ‘old’ EM physicsNew variant with ‘old’ EM physics QGSP_EMV uses multiple scattering with 7.1 QGSP_EMV uses multiple scattering with 7.1

parametersparameters


MigrationsMigrations

►Migrations:Migrations: Use of <sstream> instead of <strstream>Use of <sstream> instead of <strstream> Support for CLHEP-2.0.X (compatible with 1.9.X Support for CLHEP-2.0.X (compatible with 1.9.X

series)series)► Changes required in User CodeChanges required in User Code

Fast parameterisationFast parameterisation►Region replaces ‘envelope’. Region replaces ‘envelope’.

Creating and instantiating physics lists : Creating and instantiating physics lists : impact of the revised, "non-static", particle impact of the revised, "non-static", particle definitionsdefinitions

G4VProcess base classG4VProcess base class►StartTracking() now has argument const G4Track* StartTracking() now has argument const G4Track*


SummarySummary► Improvements in Improvements in multiple scatteringmultiple scattering process process

Addressing issues with ‘electron transport’Addressing issues with ‘electron transport’► Speedups for initialisation/navigationSpeedups for initialisation/navigation

Option to only re-optimise parts that change with runOption to only re-optimise parts that change with run New voxelisation options being studied for New voxelisation options being studied for regularregular

geometriesgeometries► Overlap checks at geometry constructionOverlap checks at geometry construction► Revised implementation of particlesRevised implementation of particles

Impacting advanced users, customizingImpacting advanced users, customizing ► Refinements in hadronic physicsRefinements in hadronic physics► Improvements in visualisation, user interfaces, …Improvements in visualisation, user interfaces, …► Migrations:Migrations:

Use of <sstream> instead of <strstream>Use of <sstream> instead of <strstream> Support for CLHEP-2.0.X (compatible with 1.9.X series)Support for CLHEP-2.0.X (compatible with 1.9.X series)

Older slidesOlder slides


Multiple Scattering model Multiple Scattering model upgradeupgrade



V. Ivantchenko, M. Maire, L. V. Ivantchenko, M. Maire, L. UrbanUrban



(Preliminary Plots!)(Preliminary Plots!)


Under developmentUnder development

►Optimized navigation for voxel phantom Optimized navigation for voxel phantom geometriesgeometries ‘‘Dancing replicas’ or Nearest neighbour Dancing replicas’ or Nearest neighbour

navigation for regular parameterised volumes.navigation for regular parameterised volumes.► Investigating approaches used by usersInvestigating approaches used by users►Parallel discussion here (later report)Parallel discussion here (later report)

► Prototype of a parallel navigatorPrototype of a parallel navigator To enable improved use of parallel geometriesTo enable improved use of parallel geometries

►Mass/physics geometry, biasing geom, tallying, fast Mass/physics geometry, biasing geom, tallying, fast simul. simul.

► Feasibility study and prototype for tunable Feasibility study and prototype for tunable tolerancestolerances

Geant4 Release 8.0 Highlights J. Apostolakis for G4.

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