Gabriele Cosmo
149 lines
4.2 KiB
Markdown
149 lines
4.2 KiB
Markdown
\page Examplegflasha Example gflasha
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This example demonstrating usage 'gflash' shower parameterisation
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in homogeneous calorimeter. Compare with glash1,2,3 the histograms
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have been added in this example. This makes it possible to use this
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example for fine tuning of GFLASH parameters.
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This example allows to compare the shower profiles from fast simulation
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with full simulation by histograming of longitudinal (slice)
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and radial profiles with different "binning".
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Then GFlash fast simulation can be "tuned" via modification
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of the model parameters file:
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include/ExGflashHomoShowerTuning.hh
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in this example.
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## Physics List
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The Physics list factory is used in this example.
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The default physics list is FTFP_BERT which has EM opt0.
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Additionally, the G4FastSimulationPhysics physics
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constructor was created to insert the G4FastSimulationManagerProcess
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that is making the interface between the fast simulation and the tracking.
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The default PHYSICS list may be changed via setting of the PHYSLIST environment
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variable, e.g.:
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```
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export PHYSLIST=FTFP_BERT_EMZ # for FTFP_BERT with opt 4 EM physics
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```
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## Geometry Definition
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In this example the calorimeter is a simple cube,
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which consists of 10 x 10 crystals of PbWO4 (CMS like).
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Geometry, sensitive detector and hits are defined respectively in:
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- ExGflashDetectorConstruction
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- ExGflashSensitiveDetector
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- ExGflashHit
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The geometry can be redefined in PreInit state via commands:
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```
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/exgflash/det/setNbCrys ncrys
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/exgflash/det/setCrysWidth width [cm]
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/exgflash/det/setCrysLength length [cm]
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```
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Materials can be chosen from Nist Materials: G4_Air G4_WATER ...
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e.g.:
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```
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/exgflash/det/setMat G4_PbWO4
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```
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see also: csi1.mac
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## Hit Scoring
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The virtual cylinder sliced longitudinally (slice) and radially (ring) was used.
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The size of the slices and rings are expressed in radiation
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length units and Moliere radius (Rm) units for rings. The number
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of division and division size in fraction of units and can be changed.
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e.g.:
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```
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/exgflash/det/setLbin 20 1. ---> 20 slices of 1. radl
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/exgflash/det/setRbin 5 0.25 ---> 5 rings of 0.25 Rm
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(MaxBin = 500 in both directions)
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```
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In ExGflashEventAction class the arrays corresponded slices and rings was
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created and filled with hists information. These arrays where use to fill
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histograms later.
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## Visualization
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The Visualization Manager is set in the main().
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The initialization of the drawing is done via the commands /vis/...
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in the macro vis.mac. To get visualization use:
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```
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/control/execute vis.mac
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```
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## How to start ?
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- Execute ExGflasha in 'batch' mode from macro files
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```
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% ./ExGflasha test.mac
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```
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- Execute ExGflasha in 'interactive mode' with visualization
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```
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% ./ExGflasha
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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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The GFLASH activated via:
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```
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/GFlash/flag 1
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```
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## Histograms
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ExGflasha produces several histograms:
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The histograms defined in ExGflashHistoManager class
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Content of these histo:
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- h0 : energy deposit per event
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- h1 : the number of hits per event
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- h2 : the energy per hit ( in MeV )
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- p0 : longitudinal energy profile
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- p1 : radial energy profile
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- p2 : cumulated longitudinal energy profile
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- p3 : cumulated radial energy profile
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To define the output file name with histograms, use the UI command :
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```
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/analysis/setFileName name
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```
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## Macros
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The macros to run in batch mode:
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- test.mac - default macro for example testing, it show how to use different application commands: redefine the histograms and profiles, change the geometry and material, etc
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- csi.mac - like test.mac but produce profiles in CsI Material
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- testLong.mac - make the runs with more statistics using default geometry and histograms setting, the material is G4_PbWO4
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- csiLong.mac - show how to run testLong.mac with different material (CsI)
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Each macro executes two runs with fast simulation flag ON (the output file
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name is set to gflash01.root ) and OFF (the output file name is set to gflash00.root )
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In addition, the ROOT macros cmpL.C, cmpR.C and cmpE.C file are provided,
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which can be used to draw superimposed full and fast histograms for radial
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and lateral profiles and also the normalized total energy deposition
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in calorimeter.
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See also [Category "parameterisations/gflash"](../../html/Examples_gflash.html) documentation.
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