Gabriele Cosmo
94 lines
3.2 KiB
Plaintext
94 lines
3.2 KiB
Plaintext
=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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Example extensibleFactory
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R. Hatcher
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Fermilab
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(based on Hadr00 by V. Ivantchenko, CERN)
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Examples in the physicslist category show the possible ways how to define
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a physics list from Geant4 physics constructors. This example demonstrates
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the usage of g4alt::G4PhysListFactory to build the concrete physics list.
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Physics List can be defined by its name given by the -p argument of the of the
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run command or by the PHYSLIST environment variable.
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./extensibleFactory -m my.macro [ -p QGSP_BERT ] \
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[ -v | --verbose ] [ -h | --help ]
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By default, FTFP_BERT Physics List will be instantiated if
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-p argument is not set and the PHYSLIST environment variable is not defined.
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This is the system default, but can be overridden using the
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SetDefaultReferencePhysList() method on the factory (see the code).
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The extensible factory allows users to define and register their own physics
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lists. This example shows the addtional a new list "MySpecialPhysList".
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./extensibleFactory -m run.mac -p MySpecialPhysList
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The extensible factory also allows for the extension of lists by adding
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(using "+" as a separator) or replacing (using "_" as a separator)
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specific physics constructors. These can be specified by
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pre-defining a short name (e.g. RADIO for G4RadioactiveDecayPhysics) or
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providing the full class name.
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./extensibleFactory -m run.mac -p FTFP_BERT_EMX+G4OpticalPhysics+RADIO
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uses the FTFP_BERT physics list as a base
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* replaces the list's standard EM portion with
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G4EmStandardPhysics_option2 ( standard EMX extension )
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* adds G4OpticalPhysics
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* adds G4RadioactiveDecayPhysics (RADIO defined in code to map to this)
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The same experimental setup is used for all examples in the physicslist
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category:
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1- Detector description
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-----------------------
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The geometry (defined in the DetectorConstruction class) consists in a box of
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scintillator material (CsI) followed by a thin box of air (screen) which is used
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to simplify scoring.
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2- Primary generator
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--------------------
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The primary generator is defined with usage of G4ParticleGun.
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The default particle is proton which hits the box perpendicular to the input face.
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The type of the particle and its energy are set in the PrimaryGeneratorAction class, and can
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be changed via the G4 built-in commands of the G4ParticleGun class.
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3- Scoring (ntuples)
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--------------------
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The screen volume is associated with a sensitive detector, ScreenSD,
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which accounts the following particle properties:
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- trackID
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- particle PDG encoding
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- particle kinetic energy
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- particle X,Y position
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- particle time
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The scored quantities are filled in the Screen ntuple, which is defined using G4AnalysisManager
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in RunAction class. The ntuple is saved in a Root file, which name is set to be equal to the
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example name in main () function.
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4- How to build
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----------------
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An additional step is needed when building the example with GNUmake
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due to using the extra shared directory:
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% cd path_to_example/example
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% gmake setup
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% gmake
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This will copy the files from shared in the example include and src;
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to remove these files:
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% gmake clean_setup
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