1. General remarks
This Geant 4 application simulate 5x5 PbWO4 crystal setup with dimensions 20x2x2 cm for each crystal. Default generated particle is 1 GeV photon. The energy of photon is hardcoded. To change it PWO25PrimaryGeneratorAction.cc should be modified and application should be recompiled. The gap between crystals is foreseen. The gap can be filled with revetment (Teflon).

2. Compilation
To compile and run application all the Geant4 and ROOT environmental variables should be set.
To compile programm simply type
> make
in programm directory.

Compiled application "PWO25" is located in $G4WORKDIR/bin/Linux-g++/
		
If the Geant4 version from pandaroot external packages is used the following linking error appears.
		
Linking PWO25 ...
/home/dimam/pandarootV2/cbmsoft/transport/geant4/lib/Linux-g++/libG3toG4.so: undefined reference to `gsdvx_'
/home/dimam/pandarootV2/cbmsoft/transport/geant4/lib/Linux-g++/libG3toG4.so: undefined reference to `gsdetv_'
...		
It can be solved by temporary removing or renaming library geant4/lib/Linux-g++/libG3toG4.so

3. Running the programm
To run the go to $G4WORKDIR/bin/Linux-g++/ directory
>./PWO25

run simulation with 1000 events
Idle> /run/beamOn 1000
Idle> exit

by default there is no gap between crystals (gap=-1).

to simulate crystals with gap and/or teflon revetment 
/PWO25/det/setUseRevetment true
/PWO25/det/setGap 3
width of the gap between crystals define also the width of teflon revetment in mm.

apply the following command when parameters are changed
/PWO25/det/update

The output file pwo25.root is produced.

4. Analysis

The macro simanalys.C produces distribution of total energy deposited in setup.
Macro, output file pwo25.root and shared library PWO25SimEvent.so should be in the same folder.