Gabriele Cosmo
171 lines
5.9 KiB
Markdown
171 lines
5.9 KiB
Markdown
\page ExampleOpNovice2 Example OpNovice2
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Investigate optical properties and parameters. Details of optical
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photon boundary interactions on a surface are recorded. Details
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of optical photon generation and transport are recorded. Group velocity
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may be examined.
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## GEOMETRY DEFINITION
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The geometry consists of a cube "box" with a side of 2 m inside
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the world cube of side 20 m. Optical properties of the box, the world,
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and the surface may be set interactively via the commands defined
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in the DetectorMessenger class.
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Material properties may be added using the macro commands:
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- for the box:
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```
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/opnovice2/boxProperty NAME EN1 V1 EN2 V2 [ .. ENn Vn]
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/opnovice2/boxConstProperty NAME VALUE
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```
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- for the world:
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```
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/opnovice2/worldProperty NAME EN1 V1 EN2 V2 [ .. ENn Vn]
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/opnovice2/worldConstProperty NAME VALUE
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```
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- for the surface:
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```
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/opnovice2/surfaceProperty NAME EN1 V1 EN2 V2 [ .. ENn Vn]
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```
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Multiple energy and value pairs may be specified for the energy-dependent
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properties.
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Values are in Geant4 internal units. Energy is in MeV.
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Example:
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```
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/opnovice2/boxProperty RINDEX 0.000002 1.3 0.000005 1.32 0.000008 1.34
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```
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sets the refractive index of the box to 1.3 at 2 eV, 1.32 at 5 eV, and
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1.34 at 8 eV.
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## PHYSICS LIST
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The FTFP_BERT physics list is used, with electromagnetic option
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EMZ (option4) and G4OpticalPhysics for the optical physics.
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## AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single particle. The type of
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the particle, its energy, position, and direction, are set
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in the PrimaryGeneratorAction class, and can be changed via the G4
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build-in commands of G4ParticleGun class (see the macros provided with
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this example).
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## VISUALIZATION
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The Visualization Manager is set in the main().
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The initialisation of the drawing is done via the commands
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/vis/... in the macro vis.mac. To get visualisation:
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```
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> /control/execute vis.mac
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```
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or run the program with no command line arguments:
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```
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$ ./OpNovice2
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```
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## HOW TO START ?
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- Execute OpNovice2 in 'batch' mode from macro files
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```
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% ./OpNovice2 electron.mac
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```
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- Execute OpNovice2 in 'interactive mode' with visualization
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```
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% ./OpNovice2
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....
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Idle> type your commands
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....
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Idle> exit
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```
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## RESULTS
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A table of optical photon events is printed at the end of the run.
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Group velocity is printed with /tracking/verbose 1 or higher.
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## HISTOGRAMS
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OpNovice2 has several predefined 1D histograms :
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- 1 : Cerenkov spectrum
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- 2 : scintillation spectrum
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- 3 : scintillation time (global time)
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- 4 : WLS absorption spectrum
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- 5 : WLS emission spectrum
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- 6 : WLS emission time
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- 7 : WLS2 absorption spectrum
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- 8 : WLS2 emission spectrum
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- 9 : WLS2 emission time
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- 10 : boundary process status
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- 11 : X momentum dir of scattered photons with px < 0
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- 12 : Y momentum dir of scattered photons with px < 0
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- 13 : Z momentum dir of scattered photons with px < 0
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- 14 : X momentum dir of scattered photons with px >= 0
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- 15 : Y momentum dir of scattered photons with px >= 0
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- 16 : Z momentum dir of scattered photons with px >= 0
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- 17 : X momentum dir of Fresnel-refracted photons
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- 18 : Y momentum dir of Fresnel-refracted photons
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- 19 : Z momentum dir of Fresnel-refracted photons
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- 20 : fraction of photons refracted (i.e. Fresnel transmission)
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- 21 : fraction of photons Fresnel-reflected
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- 22 : fraction of photons total internal reflected (TIR)
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- 23 : fraction of photons reflected (Fresnel reflection plus TIR)
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- 24 : fraction of photons absorbed at surface
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- 25 : fraction of photons "transmitted" (i.e. TRANSMITTANCE material property)
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- 26 : fraction of photons spike-reflected
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Histograms 11-26 are recorded for photons scattered from the +X
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surface of the cube. Only the first interaction is recorded.
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The histograms are managed by G4Analysis classes.
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The histos can be individually activated with the command :
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```
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/analysis/h1/set id nbBins valMin valMax
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```
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The unit is hardcoded to be eV for energy and ns for time.
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One can control the name of the histograms file with the command:
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```
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/analysis/setFileName name (default opnovice2)
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```
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It is possible to choose the format of the histogram file : root (default),
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hdf5, xml, csv, by changing the default file type in HistoManager.cc
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It is also possible to print selected histograms on an ascii file:
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```
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/analysis/h1/setAscii id
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```
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All selected histos will be written on a file name.ascii (default opnovice2)
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## MACROS
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Several macros are included.
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- boundary.mac: Set the surface to the various types and configurations of
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model, type, etc., shoot optical photons, and record statistics.
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This macro uses the command
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/opnovice2/stepping/killOnSecondSurface,
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which kills photon tracks incident on a second surface. This can
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be useful for visualizing surface scattering.
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- coated.mac: To show reflection/refraction from thin film coating
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- electron.mac: Shoot electrons and observe Cerenkov and scintillation radiation
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- fresnel.mac: Shoot optical photons of fixed polarization and random direction
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at a surface, and plot reflectance/transmittance vs incident
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angle.
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- complexRindex.mac: Use a dielectric-metal surface with a complex index of
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refraction.
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- OpNovice2.mac: Shoot an optical photon inside a box.
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- scint_by_particle.mac: Configure scintillation to have particle-specific
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yields, yield ratios, and time constants. Shoot different types
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of particles.
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- vis.mac: Configure visualization. The macro command
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/opnovice2/stepping/killOnSecondSurface, which kills photon
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tracks incident on a second surface, may be useful for
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visualizing surface scattering.
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- wls.mac: Configure two wavelength-shifting processes, and shoot optical
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photons.
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