Gabriele Cosmo
122 lines
4.4 KiB
Plaintext
122 lines
4.4 KiB
Plaintext
$Id: README,v 1.3 2001/11/27 17:06:05 gcosmo 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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TestEm8
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-------
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Test for investigation of ionisation in thin absorbers, transition
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and synchrotron radiations.
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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 TestEm8
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% gmake
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- execute TestEm5 in 'batch' mode from macro files e.g.
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% $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm8 run11.mac
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- execute TestEm5 in 'interactive' mode with visualization e.g.
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% $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm8
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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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Note that, histograms are disabled via the flag G4NOHIST in the GNUmakefile.
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Currently, histograms in this example are implemented through the obsolete
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CLHEP/Hist package, which is no longer supported. The implementation will
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be replaced by direct call to the AIDA abstract interfaces in a near future.
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