Gabriele Cosmo
97 lines
2.7 KiB
Plaintext
97 lines
2.7 KiB
Plaintext
$Id$
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///\file "optical/wls/.README"
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///\brief Example wls README page
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/*! \page Examplewls Example wls
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This application simulates the propagation of photons inside a Wave Length
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Shifting (WLS) fiber.
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\section Examplewls_s1 Geometry Definition
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The default geometry is as follow:
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- A perfect, bare, PMMA fiber: 0.5mm radius, 2m length at center(0,0,0)
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of the World.
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- A circular MPPC with 0.5mm radius at the +z end of the fiber
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- World and coupling materials are G4_AIR
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- Photons will always refracted out to coupling material before
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reaching MPPC
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- There are many flexible parameters that the user could specify.
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They are under the /WLS directory of help.
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\section Examplewls_s2 Material Choices
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There are several materials that the user can use for the fiber core,
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world and coupling.
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They are:
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- Vacuum (G4_Galactic)
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- Air (G4_AIR)
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- PMMA, n = 1.60
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- Pethylene, n = 1.49
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- FPethylene, n = 1.42
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- Polystyrene, n = 1.60
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- Silicone, n = 1.46
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\section Examplewls_s3 Photon Source
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This program uses the General Particle Source (G4GeneralParticleSource)
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provided by GEANT4 for
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generating photons. The energy of the photon must be within 2.00 eV
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to 3.47 eV. For detail instruction on how to use the General Particle
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Source, please visit their home page at:
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http://reat.space.qinetiq.com/gps/
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\section Examplewls_s4 Hit
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A hit is registered when the photon is absorbed on the MPPC surface.
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Information stored in hit includes the local coordinate of the location
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the photon is absorbed on the MPPC, the global coordinate where the
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photon left the fiber and the transit time of the photon.
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\section Examplewls_s5 Stepping Action
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The stepping action keeps track of the number of bounces a photon has
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gone through. In order to prevent infinite loop and extremely skewed
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rays taking up computing time, there is a limit of the number of
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bounces that a photon can go through before it is artificially killed.
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The default limit is 100,000. The user can set his/her own limit using
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the /stepping/setBounceLimit command. A value of 0 will turn off the
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limit. All photons artificially killed will have murderee flag turned
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on in their UserTrackInformation.
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\section Examplewls_s6 Visualization
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To visualize a photon's trajectory, simply use vis.mac macro in
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interactive mode or in your own macro.
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\section Examplewls_s7 main ()
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- Execute wls in 'batch' mode from macro files; \n
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you can enter an optional integer seed for batch mode
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\verbatim
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% wls wls.in (optional: enter an integer seed here)
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\endverbatim
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- wls in 'interactive mode' with visualization
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\verbatim
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% wls
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....
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Idle> /control/execute vis.mac
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Idle> /run/beamOn 1
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....
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Idle> exit
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\endverbatim
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*/
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