Gabriele Cosmo
106 lines
3.5 KiB
Plaintext
106 lines
3.5 KiB
Plaintext
$Id: README,v 1.3 2001/03/30 12:41:27 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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TestEm1
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-------
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This example has been setup to test individualy the electromagnetic
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processes.
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1- GEOMETRY DEFINITION
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It is a simple box which represente an 'infinite' homogeneous medium.
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Two parameters define the geometry :
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- the material of the box,
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- the (full) size of the box.
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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 of the above parameters can be changed interactively via
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the commands defined in the DetectorMessenger class.
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2- PHYSICS LIST
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The particle list is the one of novice/exampleN03.
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The physics list contains the 'standard' electromagnetic processes,
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and decay.
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Few commands have been added to PhysicsList, in order to set the
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production threshold for secondaries either in range for gamma,
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e-/e+, proton or directly in energy for all charged.
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3- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle starting at the
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middle of the box. The type of the particle and its energy are set
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in the PrimaryGeneratorAction class, and can be changed via the G4
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build-in commands of ParticleGun class (see the macros provided with
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this example).
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A RUN is a set of events.
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4- VISUALIZATION
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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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/vis~/create_view in the macro init.mac. This macro is
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automatically read from the main in case of interactive running mode.
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The detector has a default view which is a longitudinal view of the
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box.
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The tracks are drawn at the end of event, and erased at the end of run.
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Optionaly one can choose to draw all particles, only the charged one,
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or none. This command is defined in EventActionMessenger class.
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5- PHYSICS SURVEY
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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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A set of macros defining various run conditions are provided.
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The processes are actived/inactived together with differents
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cuts, in order to survey the processes one by one.
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The number of produced secondaries are counted, the number of steps,
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and the number of process calls responsible of the step.
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6- HOW TO START ?
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- compile and link to generate an executable
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% cd geant4/examples/extended/electromagnetic/TestEm1
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% gmake
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- execute TestEm1 in 'batch' mode from macro files
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% TestEm1 run10.mac
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- execute TestEm1 in 'interactive mode' with visualization
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% TestEm1
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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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7- HISTOGRAMS
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Testem1 produces several histo which are saved as testem1.paw
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Content of these histo:
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1 : track length of a charged particle
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2 : number of steps per track (charged particle)
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3 : step length (charged particle)
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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 "analysis" module in a near future.
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