Geant4 in production: Geant4 in production: status and status and

developmentsdevelopments

John Apostolakis (CERN)John Apostolakis (CERN)

Makoto Asai (SLAC)Makoto Asai (SLAC)

for the Geant4 collaborationfor the Geant4 collaboration

Geant4 in production : status and developments, CHEP 2006 2

1. Geant4’s in HEP, 1. Geant4’s in HEP, productionproduction

►HEP Experiments in large scale HEP Experiments in large scale productionproduction BaBar (2001)BaBar (2001) CMS (2003)CMS (2003) ATLAS (2004) ATLAS (2004) LHCb (2004)LHCb (2004)

►Used in many existing experimentsUsed in many existing experiments KamLAND, KamLAND, Borexino, HARP, …Borexino, HARP, …

►Used to study future experiments Used to study future experiments ILC, NA48/3 (PA326), …ILC, NA48/3 (PA326), …

Geant4 in production : status and developments, CHEP 2006 3

Geant4’s widespread useGeant4’s widespread use

► Imaging, radiotherapy, dosimetryImaging, radiotherapy, dosimetry PET and SPECT imaging (GATE), PET and SPECT imaging (GATE), brachytherapy, hadrontherapy, brachytherapy, hadrontherapy,

►Space: satelites and planetary Space: satelites and planetary missionsmissions XMM, INTEGRAL, Bepe Colombo, LISA, … XMM, INTEGRAL, Bepe Colombo, LISA, …

►Radiation assessment, dosimetryRadiation assessment, dosimetry LHCb, Electronics (TCAD), … LHCb, Electronics (TCAD), …

Geant4 in production : status and developments, CHEP 2006 4

2. Geant4 improvements2. Geant4 improvements

► Improved stability of EM energy deposition, Improved stability of EM energy deposition, resolutionresolution From revision of electron transport (Multiple From revision of electron transport (Multiple

scattering)scattering) Enables better accuracy at higher cuts - with less CPUEnables better accuracy at higher cuts - with less CPU

► Extensions to geometry modelerExtensions to geometry modeler

► Ability to revise many particle propertiesAbility to revise many particle properties

► Refinements, improvements in hadronicsRefinements, improvements in hadronics► Physics ListsPhysics Lists

Geant4 in production : status and developments, CHEP 2006 5

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 Option to only re-optimise parts that change with runrun

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

FLUKA and the Virtual Monte Carlo

Andreas MorschFor the ALICE Offline Group

CERN, Geneva, Switzerland

Computing in High Energy and Nuclear Physics13-17 February 2006, T.I.F.R., Mumbai, India

7

Integration of FLUKA into detector simulation frame-work

Advantages Full detector simulation and radiation studies

using the same detailed geometry Re-use of code for detector response

simulation as already developed for Geant3 Integration has been achieved using the

Virtual Monte Interface3 and The Root geometry modeler TGeo4

3http://root.cern.ch/root/vmc/VirtualMC.html4http://root.cern.ch

8

Virtual MC Concept Transport MC transparent to the user application

Base class TVirtualMC

UserCode

VMC

GEANT4 VMC

ParticlesHitsGEANT4

GEANT3

OutputFLUKA VMC FLUKA

Input

GEANT3 VMC

TGeo

9

Virtual Monte Carlo (VMC)

User Code

VMC

Virtual Geometrical

Modeller

G3 G3 transport

G4 transportG4

FLUKA transportFLUKA

Geometrical Modeller

Reconstruction

Visualisation

10

Validation

Validation of geometry navigation via TGeo Standard benchmark tests provided by FLUKA

authors Technical validation of the VMC

implementation Comparison with G3 results

Physics validation Comparison with test-beam data

11

Electron transport in thin layers

• 1000 electrons at 1 MeV, EM cascades

• Same final random number after simulations with FLUKA native and TFluka

•The same for all 3 tested examples

12

FLUKA/G3 Comparison Good agreement where it is expected:

Photons in electromagnetic shower

log10(step/cm) log10(E/GeV)

FLUKA VMCG3 VMC

13

Comparison with test-beam data ongoing

Silicon Pixel Detector

14

Conclusions

FLUKA VMC implementation completed Testing well advanced

TGeo/FLUKA validation completed Good agreement with G3 and Testbeam

FLUKA VMC will be used in the next ALICE Physics data challenge

Using Linux efficiently !