Gabriele Cosmo
167 lines
5.6 KiB
Plaintext
167 lines
5.6 KiB
Plaintext
$Id: README,v 1.5 2006/05/18 08:16:42 grichine 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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TestEm10
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--------
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Test for investigation of ionisation in thin absorbers, transition
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and synchrotron radiations. Default setup for "TestEm10.in" and "TestEm10.large_N.in" is
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the experiment for XTR with NIM A294 (1990) 465-472 (fig. 11) setup
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0- INTRODUCTION
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The parameterisations models can be changed simply with:
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Idle> /XTRdetector/setModel i (i = 1 to 10)
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It is NOT needed (and not recommended) to issue the command
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/XTRdetector/update if just the model is changed.
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See macro file "TestEm10.in" for an example.
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1- GEOMETRY DEFINITION
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The "absorber" is a tube made of a given material.
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Three parameters define the absorber :
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- the material of the absorber,
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- the thickness of an absorber,
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- the transverse size of the absorber (the input face is a square).
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The volume "World" contains the "absorber".
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In this test the parameters of the "World" can be changed , too.
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In addition a transverse uniform magnetic field can be applied.
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The default geometry is constructed in DetectorConstruction class,
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but all the parameters can be changed via
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the commands defined in the DetectorMessenger class.
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2- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle which hits the
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absorber 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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be changed via the G4 build-in commands of ParticleGun class (see
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the macros provided with this example).
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A RUN is a set of events.
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3- DETECTOR RESPONSE
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Here we test G4PAIionisation , G4IonisationByLogicalVolume and
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transition radiation processes
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A HIT is a record, event per event , of all the
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informations needed to simulate and analyse the detector response.
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In this example a CalorHit is defined as a set of 2 informations:
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- the total energy deposit in the absorber,
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- the total tracklength of all charged particles in the absorber,
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Therefore the absorber is declared
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'sensitive detector' (SD), which means they can contribute to the hit.
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At the end of a run, from the histogram(s), one can study
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different physics quantities such as :
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- angle distribution,
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- energy deposit,
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- transmission/backscattering,
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- ...
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The test contains 10 built-in histograms, which can be activated by
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interactive commands (see the macros runxx.mac for details).
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The histogram files can be viewed using PAW e.g with the commands
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paw> h/file 1 geant4.plot01 or g4.p11
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paw> option stat
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paw> h/pl 1
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4- PHYSICS DEMO
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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 PhysicsList class.
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The messenger classes introduce interactive commands . Using these
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commands the geometry of the detector, the data of the primary
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particle, the limits of the histograms , etc. can be changed.
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5- HOW TO START ?
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- compile and link to generate an executable
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% cd TestEm10
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% gmake
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- execute TestEm10 in 'batch' mode from macro files e.g.
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% $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10 run11.mac
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- execute TestEm10 in 'interactive' mode with visualization e.g.
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% $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10
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....
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Idle> type your commands
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....
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List of the built-in histograms
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-------------------------------
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1. number of (tracking) steps/event
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2. energy deposit distribution in the absorber (in MeV)
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3. angle distribution of the primary particle at the exit
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of the absorber (deg)
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4. distribution of the lateral displacement at exit(mm)
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5. kinetic energy of the transmitted primaries (MeV)
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6. angle distribution of the backscattered primaries (deg)
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7. kinetic energy of the backscattered primary particles (MeV)
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8. kinetic energy of the charged secondary particles (MeV)
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9. z distribution of the secondary charged vertices (mm)
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10. kinetic energy of the photons escaping the absorber (MeV)
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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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