IDEA

Geant4 simulation of the IDEA Detector

---

TRACKER - Drift chamber + vertex detector

(DIRECTORY = DriftChamberPlusVertex)

• Enter in simulation/ and edit envG4GMC.sh to change PRJBASE; then move in analyzer/ and edit envGMC.sh to change PRJBASE

• To compile the simulation part:

  cd simulation
  source envG4GMC.sh
  cd g4GMC; make clean_all; make all	
  

• To compile the analyzer:

  cd analyzer
  source envGMC.sh
  cd GMC
  source envMidasDAQ.sh
  make clean
  $ROMESYS/bin/romebuilder.exe -i GMC.xml
  make all
  

• To compile readHits (which converts the hits.root file in a suitable format for GMCAnalyzer):

  cd ../simulation/g4GMC
  make readHits
  

  N.B. The previous compilation of the analyzer part is needed because of some dependencies required.

• If everything works correctly, two executables are created in simulation/g4GMC/bin/Linux-g++: g4GMC and readHits.
  Now, before running the simulation, the IDEA geometry has to be initialized and exported in a gdml format. Edit the geometry configuration file:

  simulation/g4GMC/geom_IDEA.txt	
  

  setting TRUE the boolean variable writeGDML and choosing the gdml file name (e.g. g4-IDEA.gdml).

  After that, create an output directory for your work under in your IDEA directory (at the same level of DriftChamberPLUSVertex, e.g. IdeaTracker_TEST). To run the simulation step and generate events (from g4GMC):

  ./bin/Linux-g++/g4GMC g4mac/runPFix-1.mac geom_IDEA.txt 1 pathTo/IdeaTracker_TEST
  

  where the arguments are: 1) Geant4 card to handle the simulation parameters, 2) geometry configuration, 3) number given to the simulation, 4) output directory.

  Then type the following command to convert the file hits#.root generated by g4GMC in a suitable format for the analyzer (MCData#.root => move it in IdeaTracker_TEST):

  ./bin/Linux-g++/readHits   pathTo/IdeaTracker_TEST/hits#.root
  

N.B. It is also possible to launch the simulation in a parallelized way:

./LaunchSims.sh  $1  $2  g4mac/runPFix-1.mac geom_IDEA.txt  pathTo/IdeaTracker_TEST
./ConvertHits.sh $1  $2  pathTo/IdeaTracker_TEST

where the arguments $1 and $2 correspond to nRuns and firstRun, respectively. Here MCData#.root are automatically moved to IdeaTracker_TEST.

• Finally, modify the generated gdml file to make the simulation faster and set FALSE the boolean variable writeGDML:

  sed -e '/copynumber.*tubeFD_/,+4d' -e '/copynumber.*tubeSD_/,+4d' g4-IDEA.gdml > pathTo/IdeaTracker_TEST/g4-IDEA_reco.gdml
  

  and move geant4MC-IDEA.xml and geant4MC-IDEA-fit.xml in IdeaTracker_TEST from the analyzer/GMC directory.

• At the end, in order to run the analyzer and the reconstruction, launch (from IdeaTracker_TEST):

  ${PRJBASE}/analyzer/GMC/gmcanalyzer.exe -i geant4MC-IDEA.xml -r 1 -e 1-$nEvents
  ${PRJBASE}/analyzer/GMC/gmcanalyzer.exe -i geant4MC-IDEA-fit.xml -r 1 -e 1-$nEvents
  

  or

  ${PRJBASE}/analyzer/GMC/LaunchAnalyzer.sh $1 $2 geant4MC-IDEA.xml hits
  ${PRJBASE}/analyzer/GMC/LaunchAnalyzer.sh $1 $2 geant4MC-IDEA-fit.xml reco
  

  All data information are stored in MCHits#.root and the reconstructed data are stored in RecoData#.root, respectively. RecoData.root contains only the branch related to the reconstructed tracks. (The branches for hits in drift chamber and pixel detector are not active.)