Gabriele Cosmo
112 lines
5.6 KiB
Plaintext
112 lines
5.6 KiB
Plaintext
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=========================================================
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Geant4 - ULTRA-based air shower example
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=========================================================
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README
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---------------------
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------------------------------------------------------------------------
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----> Introduction.
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The ULTRA detector is a hybrid 2-component system consisting of:
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1) an UV detection system - the UVscope
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2) an array of scintillator detectors - the ETscope
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The UVscope detects Cherenkov light associated to cosmic ray showers
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when it is diffusively reflected on ground.
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The ETscope detects in coincidence the charged particles of the shower.
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In the current version only the UVscope simulation is included
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------------------------------------------------------------------------
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----> Description
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The UVscope consists of a Fresnel lens and a PMT located in the focal
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plane, enclosed in a cylindrical aluminum housing. The lens is 457 mm
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in diameter and is made of UV transmitting acrylic with 5.6 grooves
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per mm. The description of the geometry of the Fresnel lens makes use
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of object parameterisation/replication capabilities.
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The primary vertex generator describes a plane circular source of UV
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(3eV, about 400 nm) optical photons.
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Depending on the selected detector configuration, the source can be
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positioned such that the photons are fired
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to a reflecting surface or, by default, directly to the UVscope
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(no reflecting surface is present in this case).
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Reflection at the surface can be chosen to be specular or diffuse.
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In both cases the normal to the surface makes an angle of 45 degrees
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with the UVscope axis and the photons are emitted at an angle of
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90 degrees with the UVscope axis.
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If none of these variables is set no reflecting surface is used
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and the photons source is positioned at the UVscope axis.
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The definition of the relevant optical boundaries, parameters and
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processes is made.
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------------------------------------------------------------------------
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----> SET-UP
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A standard Geant4 example GNUmakefile and a CMakeLists.txt file are
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provided, for building with cmake
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The following environment variable can be set in order to get
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additional verbosity during program running:
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1) GNUmakefile
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setenv ULTRA_VERBOSE
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or
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2) cmake -DULTRA_VERBOSE=ON "path to source"
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------------------------------------------------------------------------
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The analysis is performed using the native Geant4 analysis tools
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(g4tools). In the default case, the output histograms are written
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in a ROOT file.
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The output file can be written in other formats (csv, xml, hdf5) by
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changing the G4AnalysisManager default file type in UltraRunAction::BeginOfRunAction().
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-----------------------------------------------------------------------
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----> How to run the example.
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From the directory where the Ultra binary resides :
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./Ultra "macro name" for running in batch mode
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./Ultra for running in interative mode.
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The macro VisDirect.mac is executed.
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Several macros are available for interactive visualisation.
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While in interactive mode type the command
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/control/execute "name_of_macro",
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where "name_of_macro" is one of the following:
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Direct.mac - a beam of photons is shot directly to the telescope.
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Mirror.mac - the beam is directed to a specular reflecing surface
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Ground.mac - the beam is directed to a diffusively reflecting surface
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------------------------------------------------------------------------
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----> Simulation output
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the output is ultra.root
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It contains:
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1)1Dhistogram with the detected photons energy (eV)
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2)1Dhistogram with the number of detected photons per event
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To plot these histograms run the ROOT macro 'do_plots.C' :
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> root do_plots.C
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------------------------------------------------------------------------
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for comments and questions: bernardo@lip.pt
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for more info http://www.ge.infn.it/geant4/examples/
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last modified: B. Tome 08/11/2019
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created by : B. Tome and M.C. Espirito Santo 20/05/2004
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