gauss - geant4 based simulation for lhcbgeant4.web.cern.ch/sites/geant4.web.cern.ch/files/... ·...
Post on 04-Jul-2020
3 Views
Preview:
TRANSCRIPT
GAUSS - GEANT4 based simulation for LHCb
GEANT4 Workshop2 October 2002W. Pokorski / CERN
02/10/2002 Gauss Application 2
Contents
Introduction to LHCb software
Overview of Gauss project
GiGa – Gaudi interface to GEANT4
Summary
02/10/2002 Gauss Application 3
GAUDI – LHCb software framework
all of the LHCb event processing software is built within a framework – Gaudi frameworkseparation between data and algorithmsdata store-centred architectural styleseparation between transient and persistent data
transient as a bridge between other representationsisolation of user codes/algorithms from underlying persistency technologies
components interact through their abstract interfacesalgorithms manipulate dataconversion services change data representations
02/10/2002 Gauss Application 4
GAUDI - Object Diagram
Converter
Algorithm
Event DataService
PersistencyService
DataFiles
AlgorithmAlgorithm
Transient Event Store
Detec. DataService
PersistencyService
DataFiles
Transient Detector
Store
MessageService
JobOptionsService
Particle Prop.Service
OtherServices Histogram
ServicePersistency
ServiceDataFiles
TransientHistogram
Store
ApplicationManager
ConverterConverterEventSelector
InteractiveService
02/10/2002 Gauss Application 5
GAUDI - Applications
GaudiGaudi
Gaudi ApplicationsGaudi Applications
GaussGauss SimulationSimulation
BrunelBrunel ReconstructionReconstruction
DaVinci DaVinci AnalysisAnalysis
PanoramixPanoramixVisualizationVisualization
PluggablePluggable ComponentsComponents
Event GenerationEvent Generation
GiGa GiGa Detector SimulationDetector Simulation
DigitizationDigitization
GaussGauss
Detector Simulation Detector Simulation GiGaGiGa
GiGa GiGa
GiGa ConversionGiGa Conversion
GiGaGiGa
Embedded Embedded Geant4Geant4Geant4Geant4 control and control and configuration, Actionsconfiguration, Actions
Conversion of Conversion of transienttransientobjects to/from objects to/from Geant4 Geant4 representationrepresentation
02/10/2002 Gauss Application 6
Gauss application
Geant4
JobOpts JobOpts
Geant4(GiGa)
DigiAlg
JobOpts
DigitMCDigit
Geometry
HepMCMCParticleMCVertex
MCHit
Generator Detector Simulation Digitization
Cnv
Cnv
Cnv
GiGa
Pythiaetc
Int.face
02/10/2002 Gauss Application 7
GiGa overview
GEANT4 Interface for Gaudi Applications orGaudi Interface to GEANT4 Applications
GEANT4 callable and controllable from within GAUDI environment
common detector geometry source used by other applications (reconstruction, visualisation) communication via Transient Stores (Event, Detector Data) as any other service or algorithm in Gaudiuse of common services (ParticlePropertySvc, RandomNumberSvc, MagneticFieldSvc, etc.)
02/10/2002 Gauss Application 8
GiGa structure
Geant4
Algorithm
EventService
PersistencyService
DataFiles
AlgorithmAlgorithm
Transient Event Store
Detec. Service
PersistencyService
DataFiles
Transient Detector
Store
ApplicationManager
GiGaService
G4 Hits
G4 Kine
GiGaKine Conversion
Service
CnvCnvConverter
OtherServices
ActionAction
GiGaHits Conversion
Service
G4 Geom
GiGaGeomConversion
Service
02/10/2002 Gauss Application 9
GiGa features
it’s a Gaudi serviceprovides access to internal G4 event loop via GiGaRunManagerall interactions with Geant4 only through abstract interfaces of GiGa Serviceminimizes the couplings to Geant4allows loading external physics listsinstantiates (using Abstract Factory pattern) different “actions” (makes them to be plugablecomponents)
02/10/2002 Gauss Application 10
GiGa - Geometry Conversion
ConverterConverter ConverterConverter
Geant4Materials
Geant4Geant4MaterialsMaterials Geant4
Volumes
Geant4Geant4VolumesVolumes
VolumesVolumesMaterialsMaterials
Xml description
Xml Cnv
Gaudi transient
store
Geo Conversion Service
02/10/2002 Gauss Application 11
Geometry conversion ex. (RICH 1)
XmlàGiGaàG4àOpenGL
02/10/2002 Gauss Application 12
GiGa - Kinematics Conversion
Geant4Geant4TrajectoriesTrajectories
Geant4Geant4PrimaryPrimaryVerticesVertices
ConverterConverter ConverterConverter
LHCbLHCbParticlesParticles
LHCbLHCbVerticesVertices
HepMC Event
ConverterConverter
Kine Conversion Service
02/10/2002 Gauss Application 13
GiGa – Hits Conversion
Hits Conversion Hits Conversion ServiceService
Geant4Hits
Geant4Geant4HitsHits Geant4
Hits
Geant4Geant4HitsHits Geant4
Hits
Geant4Geant4HitsHits
ConverterConverterConverterConverter
LHCbLHCbEcalEcal HitsHits
LHCb LHCb MuonMuon HitsHits
LHCb LHCb VeloVelo HitsHits
ConverterConverter
02/10/2002 Gauss Application 14
Detector Simulation – “physics lists”
physics lists:crucial part of the whole simulation program – will certainly require several tuning iterationsmost of the stuff already implemented in Geant4some specific processes needed implementation
for RICH: photoelectric process (creation of photoelectrons in HPDs), energy loss: in the silicon of HPDs
new feature recently added to GiGa : modular physics listsallows dynamic loading (via jobOptions) of particular physics “sublists”expected to increase flexibility and to make validation easier
02/10/2002 Gauss Application 15
Sensitive Detectors & Hits
G4TrackerHits
(Geant4)
GiGaSensDetTracker
lvVolume
(XmlDDDB)
GiGaTrackerHitsCnv
MCHits(/Event/MC/OT/Hits)
Geant4 world
Gaudi world
ProcessHit()
<logvol name="lvU_ActiveLayer" …sensdet="GiGaSensDetTracker/myDet">
creates
invoked when particle passed through the sensitive volume
converts to:
02/10/2002 Gauss Application 16
RICH1 with SingleParticleGun
Pion with 7 GeV/c.Cherenkov PhotonsIn Aerogel and C4F10.
RICH1 Event
Rayleigh scatteringSwitched off forIllustration.
S. Easo
02/10/2002 Gauss Application 17
RICH1 Hits
02/10/2002 Gauss Application 18
Panoramix view of MCHits
02/10/2002 Gauss Application 19
Panoramix view of MCHits (2)
02/10/2002 Gauss Application 20
Summary
Current Status:we can run GEANT4 simulation with all the subdetectors includedwe are able to produce MCParticles, MCHits(from LHCb event model) and save them in a ROOT filewe are testing/validating subdetector specific code and physics processeswe have started adding digitization algorithms to Gauss
02/10/2002 Gauss Application 21
Summary (2)
Planning:by end of the year: to have a complete GEANT4 based simulation application
by the summer: to perform some “test productions”
by … : to definitely move from the old GEANT3 based simulation program to the new one, GEANT4 based
top related