Gabriele Cosmo
137 lines
4.7 KiB
Plaintext
137 lines
4.7 KiB
Plaintext
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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HADR01
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A.Bagulya, I.Gudowska, V.Ivanchenko, N.Starkov
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CERN, Geneva, Switzerland
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Karolinska Institute & Hospital, Stockholm, Sweden
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Lebedev Physical Institute, Moscow, Russia
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This example application is based on the application IION developed for
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simulation of proton or ion beam interaction with a water target. Different
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aspects of beam target interaction are demonstrating in the example including
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longitudinal profile of energy deposition, spectra of secondary particles,
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spectra of particles leaving the target. The results are presenting in a form
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of average numbers and histograms.
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GEOMETRY
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The Target volume is a cylinder placed inside Check cylindrical volume. The
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Check volume is placed inside the World volume. The radius and the length of
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the Check volume are 1 mm larger than the radius and the length of the Target.
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The material of the Check volume is the same as the World material. The World
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volume has the sizes 10 mm larger than that of the Target volume. Any material
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from the Geant4 database can be defined. The default World material is
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G4Galactic and the default Target material is aluminum. The Target is
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subdivided on number of equal slices. Following UI commands are available to
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modify the geometry:
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/testhadr/TargetMat G4_Pb
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/testhadr/WorldMat G4_AIR
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/testhadr/TargetRadius 10 mm
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/testhadr/TargetLength 20 cm
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/testhadr/NumberDivZ 200
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Beam direction coincides with the target axis and is Z axis in the global
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coordinate system. The beam starts 5 mm in front of the target. G4ParticleGun
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is used as a primary generator. The energy and the type of the beam can be
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defined via standard UI commands
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/gun/energy 15 GeV
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/gun/particle proton
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Default beam position is -(targetHalfLength + 5*mm) and direction along Z axis.
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Beam position and direction can be changed by gun UI commands:
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/gun/position 1 10 3 mm
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/gun/direction 1 0 0
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however, position command is active only if before it the flag is set
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/testhadr/DefaultBeamPosition false
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SCORING
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The scoring is performed with the help of UserStackingAction class and two
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sensitive detector classes: one associated with a target slice, another with
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the Check volume. Each secondary particle is scored by the StackingAction. In
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the StackingAction it is also possible to kill all or one type of secondary
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particles
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/testhadr/Kill neutron
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/testhadr/KillAllSecondaries
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To control running the following options are available:
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/testhadr/PrintModulo 100
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/testhadr/DebugEvent 977
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The last command selects an events, for which "/tracking/verbose 2" level
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of printout is established.
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PHYSICS
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PhysicsList of the application uses reference Phsyics Lists or its components,
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which are distributed with Geant4 in /geant4/physics_lists subdirectory.
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The reference Physics List name may be defined in the 3d argument of the
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run command:
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Hadr01 my.macro QGSP_BERT
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If 3d argument is not set then the PHYSLIST environment variable is checked.
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If both are not defined then reference Phsyics Lists is not instantiated,
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instead the local Physics List is used which is built from components using
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UI interface. The choice of the physics is provided by the UI command:
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/testhadr/Physics QGSP_BIC
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To see the list of available configurations with UI one can use
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/testhadr/ListPhysics
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The cuts for electromagnetic physics can be established via
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/testhadr/CutsAll 1 mm
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/testhadr/CutsGamma 0.1 mm
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/testhadr/CutsEl 0.2 mm
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/testhadr/CutsPos 0.3 mm
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/testhadr/CutsProt 0.6 mm
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Note that testhadr UI commands are not available in the case when PHYSLIST
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environment variable is defined.
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VISUALIZATION
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For interactive mode G4 visualization options and variables should be
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defined, then the example should be recompiled:
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gmake visclean
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gmake
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HISTOGRAMS
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There are built in histograms. The 1st one (idx=0, id="1") scores energy
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deposition along the target. Histograms "22", "23", "24", "25" scores
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energy deposition per particle type.
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All other histograms are provided in decimal logarithmic scale (log10(E/MeV),
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where E is secondary particle energy at production
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It is possible to change scale and output file name using UI commands:
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/testhadr/histo/fileName name
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/testhadr/histo/setHisto idx nbins vmin vmax unit
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Only ROOT histograms are available.
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All histograms are normalized to the number of events.
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