CMSEmStandardPhysicsEMH.cc

Go to the documentation of this file.

#include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsEMH.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include <CLHEP/Units/SystemOfUnits.h>
#include "G4ParticleDefinition.hh"
#include "G4EmParameters.hh"
#include "G4EmBuilder.hh"

#include "G4MscStepLimitType.hh"

#include "G4hIonisation.hh"
#include "G4hMultipleScattering.hh"
#include "G4ionIonisation.hh"

#include "G4ParticleTable.hh"
#include "G4Gamma.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4GenericIon.hh"

#include "G4PhysicsListHelper.hh"
#include "G4BuilderType.hh"
#include "G4ProcessManager.hh"

#include "G4HepEmProcess.hh"

#include <string>

CMSEmStandardPhysicsEMH::CMSEmStandardPhysicsEMH(G4int ver, const edm::ParameterSet& p)
    : G4VPhysicsConstructor("CMSEmStandard_emh") {
  SetVerboseLevel(ver);
  G4EmParameters* param = G4EmParameters::Instance();
  param->SetDefaults();
  param->SetVerbose(ver);
  param->SetApplyCuts(true);
  param->SetStepFunction(0.8, 1 * CLHEP::mm);
  param->SetMscRangeFactor(0.2);
  param->SetMscStepLimitType(fUseSafety);
  param->SetFluo(false);
  SetPhysicsType(bElectromagnetic);
  fRangeFactor = p.getParameter<double>("G4MscRangeFactor");
  fGeomFactor = p.getParameter<double>("G4MscGeomFactor");
  fSafetyFactor = p.getParameter<double>("G4MscSafetyFactor");
  fLambdaLimit = p.getParameter<double>("G4MscLambdaLimit") * CLHEP::mm;
  std::string msc = p.getParameter<std::string>("G4MscStepLimit");
  fStepLimitType = fUseSafety;
  if (msc == "UseSafetyPlus") {
    fStepLimitType = fUseSafetyPlus;
  }
  if (msc == "Minimal") {
    fStepLimitType = fMinimal;
  }
  double tcut = p.getParameter<double>("G4TrackingCut") * CLHEP::MeV;
  param->SetLowestElectronEnergy(tcut);
  param->SetLowestMuHadEnergy(tcut);
}

CMSEmStandardPhysicsEMH::~CMSEmStandardPhysicsEMH() {}

void CMSEmStandardPhysicsEMH::ConstructParticle() {
  // minimal set of particles for EM physics
  G4EmBuilder::ConstructMinimalEmSet();
}

void CMSEmStandardPhysicsEMH::ConstructProcess() {
  if (verboseLevel > 0) {
    edm::LogVerbatim("PhysicsList") << "### " << GetPhysicsName() << " Construct EM Processes";
  }

  // This EM builder takes default models of Geant4 10 EMV.
  // Multiple scattering by WentzelVI for all particles except:
  //   a) e+e- below 100 MeV for which the Urban model is used
  //   b) ions for which Urban model is used
  G4EmBuilder::PrepareEMPhysics();

  G4PhysicsListHelper* ph = G4PhysicsListHelper::GetPhysicsListHelper();
  // processes used by several particles
  G4hMultipleScattering* hmsc = new G4hMultipleScattering("ionmsc");
  G4NuclearStopping* pnuc(nullptr);

  G4HepEmProcess* hepEmProcess = new G4HepEmProcess();
  G4Electron::Electron()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);
  G4Positron::Positron()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);
  G4Gamma::Gamma()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);

  // generic ion
  G4ParticleDefinition* particle = G4GenericIon::GenericIon();
  G4ionIonisation* ionIoni = new G4ionIonisation();
  ph->RegisterProcess(hmsc, particle);
  ph->RegisterProcess(ionIoni, particle);

  // muons, hadrons ions
  G4EmBuilder::ConstructCharged(hmsc, pnuc);
}