Gabriele Cosmo
130 lines
4.5 KiB
Plaintext
130 lines
4.5 KiB
Plaintext
$Id: README,v 1.6 2004/06/23 11:28:55 maire Exp $
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-------------------------------------------------------------------
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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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TestEm9
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-------
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This test is intended to test cut-per-region approach and to demonstrate
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electromagnetic physics in crystal calorimeter
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1- GEOMETRY DEFINITION
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The geometry consists of the vertex detector (VD), the electromagnetic
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calorimeter (EM), and the muon identifier (MU). Detector layout along
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the axis Z.
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VD consisted of 3 layers of Si with pads structured along the axis X.
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Between VD and EM there are 2 active absorbers (scintillators).
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EM is the matrix 5x5 of heavy crystals. MU consist of 2 active absorbers
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(scintillators) and the iron plate between.
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2 additional to the World regions are defined: VertexDetector and
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MuonDetector. For testing purposes first absorber of MU is included in
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the region of VD.
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Material of calorimiter and absorber can be choosen:
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Air Water lAr Al Fe BGO PbWO4 Pb.
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eg: /testem/det/CalMat PbWO4
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/testem/det/AbsMat Al
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The size of the detector can be changed also.
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eg: /testem/det/EcalLength 20 cm
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/testem/det/EcalWidth 5 cm
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/testem/det/update ---> rebuild the geometry
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2- PHYSICS LISTS
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Physics Lists are subdivided on 4 following modules:
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1. "particles" - particle definitions
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2. "general" - decays and transportation
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3. "standard" (alternative) - standard EM physics
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4. "g4v52" (alternative) - standard EM physics Geant4 5.2
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5. "binary" (optional) - binary cascade for protons and neutrons with
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energy below 3 GeV
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6. "elastic" (optional) - elastic scattering of hadrons
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3- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle which hits the
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cylinder perpendicular to the input face. The type of the particle
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and its energy are set in the PrimaryGeneratorAction class, and can
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changed via the G4 build-in commands of ParticleGun class.
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4- OUTPUT
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The batch regime of simulation can be started
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$G4WORKDIR/bin/$G4SYSTEM/TestEm9 TestEm9.in
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where TestEm9.in is the example of macro file for batch job.
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As a result of simulation the number of secondaries produced
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in different regions are averaged. The average energy depositions
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in active absorbers and EM as well as RMS of these values are shown.
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The number of hits in pads of VD is printed out.
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5- VISUALISATION
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To use visualisation the environment variable G4_VIS_USE should be
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defined. An interactive session starts if no macro file is specified
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in the command line:
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$G4WORKDIR/bin/$G4SYSTEM/TestEm9
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To start visualisation one can issur
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>/control/execute vis.mac
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>/run/beamOn 1
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6- ANALYSIS
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To create histograms/ntuple for further analysis one should define
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environment variable G4ANALYSIS_USE and setup local AIDA implementation.
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The example should be recompiled:
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gmake histclean
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gmake
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The macro file csi.mac can be used as exmple of macro for analysis. It
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can be executed in the following way:
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$G4WORKDIR/bin/$G4SYSTEM/TestEm9 csi.mac
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7- Using histograms
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-------------------
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By default the histograms are not activated. To activate histograms
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the environment variable G4ANALYSIS_USE should be defined. For instance
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uncomment the flag G4ANALYSIS_USE in GNUmakefile.
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To use histograms any of implementations of AIDA interfaces should
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be available (see http://aida.freehep.org).
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A package including AIDA and extended interfaces also using Python
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is PI, available from: http://cern.ch/pi .
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Once installed PI or PI-Lite in a specified local area $MYPY, it is
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required to add the installation path to $PATH, i.e. for example,
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for release 1.2.1 of PI:
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setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin
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CERN users can use the PATH to the LCG area on AFS.
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Before compilation of the example it is optimal to clean up old
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files:
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gmake histclean
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gmake
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Before running the example the command should be issued:
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eval `aida-config --runtime csh`
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It is possible to choose the format of the output file with
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histograms using UI command:
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/testem/histo/setFileType type
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The following types are available: hbook, root, xml.
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