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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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HADR02
Example and DMJET: V.Ivanchenko, A.Ivanchenko,
UrQMD: Kh Abdel-Waged et al, A. Dotti
CERN, Geneva, Switzerland
Geant4 Associate International
University of Bordeaux, CENBG/IN2P3/CNRS
(ESA contract 22712/09/NL/AT)
This example application is providing simulation of ion beam interaction with different
targets. Hadronic aspects of beam target interaction are demonstrated in the example
including longitudinal profile of energy deposition, spectra of secondary particles,
isotope production spectra. The results are presenting in a form of average numbers
and histograms. All ion/ion models of Geant4 are available.
In addition an interface to the FORTRAN code UrQMD-1.3rc developed by Kh, Abdel-Waged et al
for the KACST/NCMP. UrQMD model by S.A.Bass et al. Prog.Part.Nucl.Phys. 41 (1998) 225
and M.Bleicher et al. J.Phys. G25 (1999) 1859.
UrQMD can be used only for ion-ion physics or for all hadronic inelastic interactions.
INSTALLATION
For simulation with Geant4 native models installation procedure is the same as for
other examples.
HOW TO RUN
To run the example:
Hadr02 <yourmacro> QGSP_BIC
The last parameter is optional. It is the name of Geant4 reference Physics List,
alternatively Physics List can be defined via environment variable
setenv PHYSLIST QGSP_BIC
ACTIVATION OF URQMD INTERFACE
UrQMD 1.3 FORTRAN code is NOT provided with Geant4 code-base.
You can get UrQMD code from UrQMD code website: http://urqmd.org
The Geant4 interface has been developed and tested against urqmd-1.3cr
Once the tarball urqmd-1.3cr.tar.gz has been downloaded copy it in the
urqmd1_3 directory of this example.
To compile support for UrQMD interface in the example define the environment
variable G4_USE_URQMD. i.e. by typing:
setenv G4_USE_URQMD 1
Two possible uses of UrQMD interface are possible: use UrQMD code only for
ion-ion interactions or use the provided UrQMD physics list (all hadron inelastic interactions
use UrQMD).
To run the example with UrQMD only for ion-ion physics:
Hadr02 urqmd.in QGSP_BIC
The last parameter is optional. It is the name of Geant4 reference Physics List on
top of which a new ion physics is added. Alternatively Physics List can be defined via
environment variable
setenv PHYSLIST QGSP_BIC
To run the example with the full UrQMD physics:
Hadr02 default.in UrQMD
or:
setenv PHYSLIST UrQMD
Hadr02 default.in
UrQMD physics list can be used in any application, releavant headers and source files (*UrQDM*)
should be copied in your application source tree, together with the urqmd1_3 sub-directory.
Your application makefile should also be modified following the example of the makefile for this
example.
GEOMETRY
The Target volume is a cylinder placed inside Check cylindrical volume. The
Check volume is placed inside the World volume. The radius and the length of
the Check volume are 1 mm larger than the radius and the length of the Target.
The material of the Check volume is the same as the World material. The World
volume has the sizes 10 mm larger than that of the Target volume. Any material
from the Geant4 database can be defined. The default World material is
G4Galactic and the default Target material is aluminum. The Target is
subdivided on number of equal slices. Following UI commands are available to
modify the geometry:
/testhadr/TargetMat G4_Pb
/testhadr/WorldMat G4_AIR
/testhadr/TargetRadius 10 mm
/testhadr/TargetLength 20 cm
/testhadr/NumberDivZ 200
Beam direction coincides with the target axis and is Z axis in the global
coordinate system. G4ParticleGun is used as a primary generator. The energy
and the type of the beam can be defined via standard UI commands
/gun/energy 150 GeV
/gun/particle ion
/gun/ion 6 12
Default beam position is -(targetHalfLength + 5*mm) and direction along Z axis.
Beam position and direction can be changed by gun UI commands:
/gun/position 1 10 3 mm
/gun/direction 1 0 0
however, position command is active only if before it the flag is set
/testhadr/DefaultBeamPosition false
SCORING
The scoring is performed with the help of UserStackingAction class and a
sensitive detector class associated with a target slice.
Each secondary particle is scored by the StackingAction. In
the StackingAction it is also possible to kill all or only EM (e+, e-, gamma)
secondary particles
/testhadr/killAll
/testhadr/KillEM
To control running the following options are available:
/run/printProgress 10
PHYSICS
PhysicsList of the application uses components, which are distributed with
Geant4 in /geant4/physics_lists subdirectory.
Reference Physics Lists are used and the environment variable PHYSLIST should
be defined.
Additionally it is possible to add ion-ion interactions using UI command
/testhadr/ionPhysics HIJING
/testhadr/ionPhysics QrQMD
VISUALIZATION
For interactive mode G4 visualization options and variables should be
defined, then the example should be recompiled:
gmake visclean
gmake
The vis.mac file can be used an example of visualization. The following command can
be used:
/testhadr/DrawTracks charged
/testhadr/DrawTracks charged+n
/testhadr/DrawTracks neutral
/testhadr/DrawTracks all
HISTOGRAMS
All histograms are normalized to the number of events.
Gabriele Cosmo