This example demonstrates usage 'gflash' shower parameterisation in homogeneous calorimeter. Compare with glash1,2,3 in this example histograms was added. This makes it possible to use this example for fine tuning of GFLASH parameters.

This example allows to compare the shower profiles from fast simulation with full simulation by histograming of longitudinal (slice) and radial profiles with different "binning". Then GFlash fast simulation can be "tuned" via modification of the model parameters file:

in this example.

Physics List

The Physics list factory is used in this example. The default physics list is FTFP_BERT which has EM opt0. Additionally the G4FastSimulationPhysics physics constructor was created to insert the G4FastSimulationManagerProcess that is making the interface between the fast simulation and the tracking.

THe default PHYSICS list may be changed via setting of the PHYSLIST environment variable, e.g:

export PHYSLIST=FTFP_BERT_EMZ # for FTFP_BERT with opt 4 EM physics

Geometry Definition

In this example the calorimeter is a simple cube, which consists of 10 x 10 crystals of PbWO4 (CMS like).

Geometry, sensitive detector and hits are defined respectively in:

Materials can be choosen from Nist Materials: G4_Air G4_WATER ... eg:

/exgflash/det/setMat G4_PbWO4

Hit Scoring

The virtual cylinder sliced longitudinally (slice) and radially (ring) was used. The size of the slices and rings are expressed in radiation length units and can be changed. eg:

/exgflash/det/setLbin 20   1.    ---> 20 slices of 1. radl
/exgflash/det/setRbin  5   0.25  --->  5 rings of 0.25 radl
     (MaxBin = 500 in both directions)

In ExGflashEventAction class the arrays corresponded slices and rings was created and filled with hists information. This arrays was use to fill histograms later.

Visualization

The Visualization Manager is set in the main(). The initialization of the drawing is done via the commands /vis/... in the macro vis.mac. To get visualization:

/control/execute vis.mac

How to start ?

Execute ExGflasha in 'batch' mode from macro files
```
 % ExGflasha   test.mac
```

Execute ExGflasha in 'interactive mode' with visualization

 % ExGflasha
   ....
  Idle> type your commands
  ....
  Idle> exit

The GFLASH activated via:

/GFlash/flag 1

Histograms

ExGflasha produces several histograms: The histograms defined in ExGflashHistoManager class

Content of these histo:

h0 : energy deposit per event
h1 : the number of hits per event
h2 : the energy per hit ( in MeV )
p0 : longitudinal energy profile
p1 : radial energy profile
p2 : cumulated longitudinal energy profile
p3 : cumulated radial energy profile

To define the output file name with histograms, use the UI command :

/analysys/setFileName name

Macros

The macros to run in batch mode:

test.mac - default macro for example testing
run01.mac - show how redefine the histograms
csi1.mac - macro which produce profiles in CsI Material
test0.mac - profile caparison, long run without GFLASH
test1.mac - profile comprising, long run with GFLASH on