Gabriele Cosmo
134 lines
4.6 KiB
Plaintext
134 lines
4.6 KiB
Plaintext
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=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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lArCal
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--------
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This example is intended to simulate the Liquid Argon Calorimeter
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of the ATLAS Detector at LHC.
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1. GEOMETRY DEFINITION
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------------------------
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The liquid Argon calorimeter consists of two modules; an electromagnetic
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and a hadronic one whose geometry parameters are defined in
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FCALEMModuleParameters.input and FCALHadModuleParameters.input files.
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It contains a FCALTestbemSetup class whose geometry is given by
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FCALTestbeamSetupParameters.input. See these files for details concerning to
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radius, lenght and angles of the different components.
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2. AN EVENT : THE PRIMARY GENERATOR
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------------------------------------
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The primary kinematic consists of a single particle which hits the
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geometry perpendicular to the input face. The FCALPrimaryGeneratorAction
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class gives the particle and its energy (by default it is an electron of
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80 GeV). Theses parameters can be changed in commands of ParticleGun class
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inside the macros given in this example.
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The subdirectory data-tracks contains the kinematic files
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of the particles for different energies (20 GeV, 40 GeV, 60 GeV, 80 GeV,
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120 GeV and 200 GeV).
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The information given inside these files are the X, Y, Z and cosX,
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cosY, cosZ variables for each event.
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A RUN is a set of events.
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3. VISUALIZATION
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------------------
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The Visualization Manager is set in the main().
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The initialisation of the drawing is done via the command
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> /control/execute vis.mac
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The detector has a default view which is a transversal view of the geometry.
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The tracks are drawn at the end of event, and erased at the end of run.
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Optionally the way of drawing the particles can be changed in the
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TBEVentActionMessenger class.
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4. PHYSICS DEMO
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-----------------
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The particle's type and the physic processes which will be available
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in this example are set in FCALPhysicsList class.
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In addition a build-in interactive command (/process/inactivate proname)
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allows to activate/inactivate the processes one by one.
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The threshold for producing secondaries can be changed.
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eg: /run/particle/setCut 100 micrometer
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/run/initialize
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5. HOW TO START ?
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-----------------
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- compile and link to generate an executable
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% cd geant4/examples/advanced/lAr_calorimeter/lArcal
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% gmake
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- execute the program in 'batch' mode from macro files
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% lArcal prerunlAr.mac
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- execute Test in 'interactive mode' with visualization
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% lArcal
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....
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Idle> type your commands
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....
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Idle> exit
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6. HISTOGRAMS
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--------------
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lArcal produces 4 histograms (saved as fcal.paw) which illustrate
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the final state of the most important variables of the example:
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Histo1 --> Number of tracks out of World
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Histo2 --> Number of secondary particles
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Histo3 --> Electromagnetic Energy deposit in the EMModule
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Histo4 --> Hadronic Energy deposit in the HadModule
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The example generates 3 ntuples too which contains the same information
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than the histograms.
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See their definitions in FCALRunAction.cc
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Note that histograms are disabled via the flag G4ANALYSIS_USE in GNUmakefile.
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7. Using the Anaphe implementation of the AIDA 3.0 histograms:
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---------------------------------------------------------------
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In order to use the new Anaphe implementation of the AIDA 3.0 interfaces,
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prepare some environment variables by source-ing one of the following
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startup scripts.
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# This example has been developed and tested with the gcc-2.95.2 compiler:
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----------
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o Set up the environment variable: G4ANALYSIS_USE
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o setenv PATH ${PATH}:/afs/cern.ch/sw/lhcxx/specific/redhat72/gcc-2.95.2/5.0.2/bin
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(Hier your system must be specified;
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if it is redhat61 or redhat73... this
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link has to be changed to the
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corresponding system.)
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o source /afs/cern.ch/sw/lhcxx/share/LHCXX/5.0.2/install/sharedstart.csh or .sh
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o ln -s /afs/cern.ch/sw/lhcxx/share/LHCXX/5.0.2/scripts/* ~/bin/.
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(This has to be made only one)
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After this, you will have access to the 'aida-config' command which
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is used in the GNUmakefile.
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