EXPERT ROOT

void NeuRad_sim(Int_t nEvents = 100){

  //---------------------Files-----------------------------------------------

  TString outFile= "sim.root";

  TString parFile= "par.root";

  // ------------------------------------------------------------------------

  // -----   Timer   --------------------------------------------------------

  TStopwatch timer;

  timer.Start();

  // ------------------------------------------------------------------------

  // -----   Create simulation run   ----------------------------------------

  FairRunSim* run = new FairRunSim();

  /** Select transport engine

  * TGeant3

  * TGeant4

  **/

  run->SetName("TGeant4");              // Transport engine

  run->SetOutputFile(outFile.Data());          // Output file

  // ------------------------------------------------------------------------

  // -----   Runtime database   ---------------------------------------------

  FairRuntimeDb* rtdb = run->GetRuntimeDb();

  // ------------------------------------------------------------------------

  // -----   Create media   -------------------------------------------------

  run->SetMaterials("media.geo");       // Materials

  // ------------------------------------------------------------------------

  //-------- Set MC event header --------------------------------------------

  ERMCEventHeader* header = new ERMCEventHeader();

  run->SetMCEventHeader(header);

  //-------------------------------------------------------------------------

  // -----   Create detectors  ----------------------------------------------        

  FairModule* cave= new ERCave("CAVE");

  cave->SetGeometryFileName("cave.geo");

  run->AddModule(cave);

  ERCollimator* collimator = new ERCollimator();

  collimator->SetGeometryFileName("collimator.geo.root");

  run->AddModule(collimator);

  // ER NeuRad definition

  /* Select verbosity level

   * 1 - only standard logs

   * 2 - Print points after each event

   * 3 - - GEANT Step information

  */

  Int_t verbose = 1;

  ERNeuRad* neuRad= new ERNeuRad("ERNeuRad", kTRUE,verbose);

  neuRad->SetGeometryFileName("NeuRad.v4.geo.root");

  /* Select storing stepss

   * not store steps

   * SetStorePrimarySteps() - store only primary particle step

   * SetStoreAllSteps() - store all steps. WARNING - very slow

  */

  neuRad->SetStorePrimarySteps();

  run->AddModule(neuRad);

  // ------------------------------------------------------------------------

  // -----   Create PrimaryGenerator   --------------------------------------

  FairPrimaryGenerator* primGen = new FairPrimaryGenerator();

  Int_t pdgId = 22; // gamma  beam

  Double32_t theta1 = 0.;  // polar angle distribution

  Double32_t theta2 = 0.001*TMath::RadToDeg();  // degree

  Double32_t kin_energy = .000660; //GeV

  Double_t mass = TDatabasePDG::Instance()->GetParticle(pdgId)->Mass();

  Double32_t momentum = TMath::Sqrt(kin_energy*kin_energy + 2.*kin_energy*mass); //GeV

  FairBoxGenerator* boxGen = new FairBoxGenerator(pdgId, 1);

  boxGen->SetThetaRange(theta1, theta2);

  boxGen->SetPRange(momentum, momentum);

  boxGen->SetPhiRange(0, 360);

  //boxGen->SetXYZ(0.3,0.3,55.);

  boxGen->SetBoxXYZ(0., 0.6,0., 0.6,0.);

  primGen->AddGenerator(boxGen);

  run->SetGenerator(primGen);

  // ------------------------------------------------------------------------

  //-------Set visualisation flag to true------------------------------------

  run->SetStoreTraj(kTRUE);

  //-------Set LOG verbosity  ----------------------------------------------- 

  FairLogger::GetLogger()->SetLogVerbosityLevel("LOW");

  // -----   Initialize simulation run   ------------------------------------

  run->Init();

  Int_t nSteps = -15000;

  //gMC->SetMaxNStep(nSteps);

  // -----   Runtime database   ---------------------------------------------

  Bool_t kParameterMerged = kTRUE;

  FairParRootFileIo* parOut = new FairParRootFileIo(kParameterMerged);

  parOut->open(parFile.Data());

  rtdb->setOutput(parOut);

  rtdb->saveOutput();

  rtdb->print();

  // ---------------------------------------------------------

  // -----   Run simulation  ------------------------------------------------

  run->Run(nEvents);

  // -----   Finish   -------------------------------------------------------

  timer.Stop();

  Double_t rtime = timer.RealTime();

  Double_t ctime = timer.CpuTime();

  cout << endl << endl;

  cout << "Macro finished succesfully." << endl;

  cout << "Output file is sim.root" << endl;

  cout << "Parameter file is par.root" << endl;

  cout << "Real time " << rtime << " s, CPU time " << ctime

                  << "s" << endl << endl;

}