Gabriele Cosmo
41 lines
1.7 KiB
Plaintext
41 lines
1.7 KiB
Plaintext
This is an example of how to use "generic biasing" to get the following
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functionality which is currently not available directly in the Geant4
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hadronic framework.
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We want to use the physics list FTFP_BERT everywhere in our detector,
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except that in one (or more) logical volume(s) we want to use a
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different combination of hadronic models, e.g. FTFP + INCLXX
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(instead of the default FTFP + BERT), for the final-state generation.
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Notice that we use the powerful "generic biasing" machinery available
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in Geant4, but the actual weights of all tracks remain to the usual
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value (1.0) as in the normal (unbiased) case.
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In this example, the detector is very simple:
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- a homogeneous block of silicon, as a proxy of a tracker sub-detector;
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- followed by a crystal, as a proxy of an electromagnetic calorimeter;
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- followed by a homogeneous block of iron, as a proxy of a hadron
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calorimeter.
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We assume that the block of silicon is where we want to replace FTFP+BERT
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with FTFP+INCLXX for the final-state modeling of proton, neutron, pion-
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and pion+-inelastic interactions (of any energy).
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This silicon layer is made artificially thick (20 cm) in order to have
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more hadron inelastic interactions for testing.
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This example has been tested only for G4 10.5.p01 and 10.6, but it should
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work also for previous recent releases (i.e. 10.4 and 10.3).
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The example works in both sequential and multi-threaded modes, and the
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CPU overhead due to "generic biasing" for this application seems to be
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very small (at the per-cent level).
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To build it:
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mkdir Build; cd Build
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cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo \
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-DGeant4_DIR=/path-to-geant4-libraries ../.
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make
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To run it:
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./Hadr08 hadr08.in
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which shoot 100 pion+ of 5 GeV kinetic energy.
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