G4MuNeutrinoNucleusProcess.cc

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//
// Geant4 Hadron Elastic Scattering Process 
// 
// Created  from G4HadronElasticProcess
//  
// Modified:
//
// 2.2.19 V.Grichine - PostStepDoIt implementation
// 24.04.19 V. Grichine - G4Region name and optionally total cross section biased in the region only.
 
#include <iostream>
#include <typeinfo>
 
#include "G4MuNeutrinoNucleusProcess.hh"
#include "G4SystemOfUnits.hh"
#include "G4Nucleus.hh"
#include "G4HadronicException.hh"
#include "G4ProcessManager.hh"
#include "G4CrossSectionDataStore.hh"
#include "G4ProductionCutsTable.hh"
#include "G4HadronicInteraction.hh"
#include "G4VCrossSectionRatio.hh"
#include "G4VDiscreteProcess.hh"
 
#include "G4MuNeutrinoNucleusTotXsc.hh"
 
#include "G4RotationMatrix.hh"
#include "G4ThreeVector.hh"
#include "G4AffineTransform.hh"
#include "G4DynamicParticle.hh"
#include "G4StepPoint.hh"
#include "G4VSolid.hh"
#include "G4LogicalVolume.hh"
#include "G4SafetyHelper.hh"
#include "G4TransportationManager.hh"
 
///////////////////////////////////////////////////////////////////////////////
 
 
G4MuNeutrinoNucleusProcess::G4MuNeutrinoNucleusProcess(const G4String& anEnvelopeName, const G4String& pName)
  : G4HadronicProcess( pName, fNuNucleus )
{
  lowestEnergy = 1.*keV;
  fEnvelopeName = anEnvelopeName;
  fTotXsc = new G4MuNeutrinoNucleusTotXsc();
   safetyHelper = G4TransportationManager::GetTransportationManager()->GetSafetyHelper();
  safetyHelper->InitialiseHelper();
}
 
///////////////////////////////////////////////////////
 
void G4MuNeutrinoNucleusProcess::SetBiasingFactor(G4double bf)
{
  fNuNuclTotXscBias = bf;
}
 
///////////////////////////////////////////////////////
 
void G4MuNeutrinoNucleusProcess::SetBiasingFactors(G4double bfCc, G4double bfNc)
{
  fNuNuclCcBias = bfCc;
  fNuNuclNcBias = bfNc;
  fNuNuclTotXscBias = std::max(fNuNuclCcBias, fNuNuclNcBias);
}
 
///////////////////////////////////////////////
 
G4double G4MuNeutrinoNucleusProcess::PostStepGetPhysicalInteractionLength( const G4Track& track,
                                      G4double previousStepSize,
                                      G4ForceCondition* condition )
{
  return G4VDiscreteProcess::PostStepGetPhysicalInteractionLength(  track,
                                       previousStepSize,  condition );
}
 
//////////////////////////////////////////////////
 
G4double G4MuNeutrinoNucleusProcess::
GetMeanFreePath(const G4Track &aTrack, G4double, G4ForceCondition *)
{
  //G4cout << "GetMeanFreePath " << aTrack.GetDefinition()->GetParticleName()
  //     << " Ekin= " << aTrack.GetKineticEnergy() << G4endl;
  G4String rName = aTrack.GetStep()->GetPreStepPoint()->GetPhysicalVolume()->GetLogicalVolume()->GetRegion()->GetName();
  G4double totxsc = GetCrossSectionDataStore()->ComputeCrossSection(aTrack.GetDynamicParticle(),
                            aTrack.GetMaterial());
 
  if( rName == fEnvelopeName && fNuNuclTotXscBias > 1.)
  {
    totxsc *= fNuNuclTotXscBias;
  }
  G4double res = (totxsc>0.0) ? 1.0/totxsc : DBL_MAX;
  //G4cout << "         xsection= " << totxsc << G4endl;
  return res;
}
 
///////////////////////////////////////////////////
 
void G4MuNeutrinoNucleusProcess::ProcessDescription(std::ostream& outFile) const
{
  outFile << "G4MuNeutrinoNucleusProcess handles the scattering of \n"
      << "neutrino on electrons by invoking the following  model(s) and \n"
      << "cross section(s).\n";
}
 
///////////////////////////////////////////////////////////////////////
 
G4VParticleChange* 
G4MuNeutrinoNucleusProcess::PostStepDoIt(const G4Track& track, const G4Step& step)
{
  G4String rName = track.GetStep()->GetPreStepPoint()->GetPhysicalVolume()->GetLogicalVolume()->GetRegion()->GetName();
 
  if( rName != fEnvelopeName ) 
  {
    if( verboseLevel > 0 )
    {
      G4cout<<"Go out from G4MuNeutrinoNucleusProcess::PostStepDoIt: wrong volume "<<G4endl;
    }
    return G4VDiscreteProcess::PostStepDoIt( track,  step );
  }
  theTotalResult->Clear();
  theTotalResult->Initialize(track);
  G4double weight = track.GetWeight();
  theTotalResult->ProposeWeight(weight);
 
  if( track.GetTrackStatus() != fAlive ) 
  { 
    return theTotalResult; 
  }
  // Next check for illegal track status
  //
  if (track.GetTrackStatus() != fAlive && 
      track.GetTrackStatus() != fSuspend) 
  {
    if (track.GetTrackStatus() == fStopAndKill ||
        track.GetTrackStatus() == fKillTrackAndSecondaries ||
        track.GetTrackStatus() == fPostponeToNextEvent) 
    {
      G4ExceptionDescription ed;
      ed << "G4HadronicProcess: track in unusable state - "
     << track.GetTrackStatus() << G4endl;
      ed << "G4HadronicProcess: returning unchanged track " << G4endl;
      DumpState(track,"PostStepDoIt",ed);
      G4Exception("G4HadronicProcess::PostStepDoIt", "had004", JustWarning, ed);
    }
    // No warning for fStopButAlive which is a legal status here
    return theTotalResult;
  }
    
  // For elastic scattering, _any_ result is considered an interaction
  ClearNumberOfInteractionLengthLeft();
 
  G4double kineticEnergy = track.GetKineticEnergy();
  const G4DynamicParticle* dynParticle = track.GetDynamicParticle();
  const G4ParticleDefinition* part = dynParticle->GetDefinition();
  const G4String pName = part->GetParticleName();
 
  // NOTE:  Very low energy scatters were causing numerical (FPE) errors
  //        in earlier releases; these limits have not been changed since.
 
  if ( kineticEnergy <= lowestEnergy ) return theTotalResult;
 
  const G4Material* material = track.GetMaterial();
  G4Nucleus* targNucleus = GetTargetNucleusPointer();
 
  ///// uniform random spread of the neutrino interaction point ////////////
 
  const G4StepPoint* pPostStepPoint  = step.GetPostStepPoint();
  const G4DynamicParticle* aParticle = track.GetDynamicParticle();
  G4ThreeVector      position  = pPostStepPoint->GetPosition(), newPosition=position;
  G4ParticleMomentum direction = aParticle->GetMomentumDirection();
  
  if( fNuNuclCcBias > 1.0 ||  fNuNuclNcBias > 1.0) // = true, if fBiasingfactor != 1., i.e. xsc is biased
  {
    const G4RotationMatrix* rotM = pPostStepPoint->GetTouchable()->GetRotation();
    G4ThreeVector transl = pPostStepPoint->GetTouchable()->GetTranslation();
    G4AffineTransform transform = G4AffineTransform(rotM,transl);
    transform.Invert();
 
    G4ThreeVector localP = transform.TransformPoint(position);
    G4ThreeVector localV = transform.TransformAxis(direction);
 
    G4double forward  = track.GetVolume()->GetLogicalVolume()->GetSolid()->DistanceToOut(localP,  localV);
    G4double backward = track.GetVolume()->GetLogicalVolume()->GetSolid()->DistanceToOut(localP, -localV);
 
    G4double distance = forward+backward;
 
    // G4cout<<distance/cm<<", ";
 
    // uniform sampling of nu-e interaction point 
    // along neutrino direction in current volume
 
    G4double range = -backward+G4UniformRand()*distance;
 
    newPosition = position + range*direction;
 
    safetyHelper->ReLocateWithinVolume(newPosition);
 
    theTotalResult->ProposePosition(newPosition); // G4Exception : GeomNav1002
  }
  G4HadProjectile theProj( track );
  G4HadronicInteraction* hadi = nullptr;
  G4HadFinalState* result = nullptr;
  const G4Element* elm =
    GetCrossSectionDataStore()->SampleZandA(dynParticle, material, *targNucleus);
  G4int ZZ = elm->GetZasInt();
  fTotXsc->GetElementCrossSection(dynParticle, ZZ, material);  
  G4double ccTotRatio = fTotXsc->GetCcTotRatio();
 
  if( G4UniformRand() < ccTotRatio )  // Cc-model
  {
    // Initialize the hadronic projectile from the track
    thePro.Initialise(track);
 
    if (pName == "nu_mu" ) hadi = (GetHadronicInteractionList())[0];
    else                   hadi = (GetHadronicInteractionList())[2];
 
    result = hadi->ApplyYourself( thePro, *targNucleus);
   
    result->SetTrafoToLab(thePro.GetTrafoToLab());
 
    ClearNumberOfInteractionLengthLeft();
 
    FillResult(result, track);
  }
  else  // Nc-model                            
  {
    if (pName == "nu_mu" ) hadi = (GetHadronicInteractionList())[1]; 
    else                   hadi = (GetHadronicInteractionList())[3];
 
    std::size_t idx = track.GetMaterialCutsCouple()->GetIndex();
 
    G4double tcut = (*(G4ProductionCutsTable::GetProductionCutsTable()->GetEnergyCutsVector(3)))[idx];
 
    hadi->SetRecoilEnergyThreshold(tcut);
 
    if( verboseLevel > 1 ) 
    {
    G4cout << "G4MuNeutrinoNucleusProcess::PostStepDoIt for " 
       << part->GetParticleName()
       << " in " << material->GetName() 
       << " Target Z= " << targNucleus->GetZ_asInt() 
       << " A= " << targNucleus->GetA_asInt() << G4endl; 
    }
    try
    {
      result = hadi->ApplyYourself( theProj, *targNucleus);
    }
    catch(G4HadronicException & aR)
    {
      G4ExceptionDescription ed;
      aR.Report(ed);
      ed << "Call for " << hadi->GetModelName() << G4endl;
      ed << "  Z= " 
     << targNucleus->GetZ_asInt() 
     << "  A= " << targNucleus->GetA_asInt() << G4endl;
      DumpState(track,"ApplyYourself",ed);
      ed << " ApplyYourself failed" << G4endl;
      G4Exception("G4MuNeutrinoNucleusProcess::PostStepDoIt", "had006", 
          FatalException, ed);
    }
    // directions
 
    G4ThreeVector indir = track.GetMomentumDirection();
    G4double phi = CLHEP::twopi*G4UniformRand();
    G4ThreeVector it(0., 0., 1.);
    G4ThreeVector outdir = result->GetMomentumChange();
 
    if(verboseLevel>1) 
    {
      G4cout << "Efin= " << result->GetEnergyChange()
       << " de= " << result->GetLocalEnergyDeposit()
       << " nsec= " << result->GetNumberOfSecondaries()
       << " dir= " << outdir
       << G4endl;
    }
    // energies 
 
    G4double edep = result->GetLocalEnergyDeposit();
    G4double efinal = result->GetEnergyChange();
 
    if(efinal < 0.0) { efinal = 0.0; }
    if(edep < 0.0)   { edep = 0.0; }
 
    // NOTE:  Very low energy scatters were causing numerical (FPE) errors
    //        in earlier releases; these limits have not been changed since.
 
    if(efinal <= lowestEnergy) 
    {
      edep += efinal;
      efinal = 0.0;
    }
    // primary change
 
    theTotalResult->ProposeEnergy(efinal);
 
    G4TrackStatus status = track.GetTrackStatus();
 
    if(efinal > 0.0) 
    {
      outdir.rotate(phi, it);
      outdir.rotateUz(indir);
      theTotalResult->ProposeMomentumDirection(outdir);
    } 
    else 
    {
      if( part->GetProcessManager()->GetAtRestProcessVector()->size() > 0)
      { 
        status = fStopButAlive; 
      }
      else 
      { 
        status = fStopAndKill; 
      }
      theTotalResult->ProposeTrackStatus(status);
    }
    //G4cout << "Efinal= " << efinal << "  TrackStatus= " << status << G4endl;
 
    theTotalResult->SetNumberOfSecondaries(0);
 
    // recoil
 
    if( result->GetNumberOfSecondaries() > 0 ) 
    {
      G4DynamicParticle* p = result->GetSecondary(0)->GetParticle();
 
      if(p->GetKineticEnergy() > tcut) 
      {
        theTotalResult->SetNumberOfSecondaries(1);
        G4ThreeVector pdir = p->GetMomentumDirection();
 
        // G4cout << "recoil " << pdir << G4endl;
        //!! is not needed for models inheriting G4MuNeutrinoNucleus
 
        pdir.rotate(phi, it);
        pdir.rotateUz(indir);
 
        // G4cout << "recoil rotated " << pdir << G4endl;
 
        p->SetMomentumDirection(pdir);
 
        // in elastic scattering time and weight are not changed
 
        G4Track* t = new G4Track(p, track.GetGlobalTime(), 
                   track.GetPosition());
        t->SetWeight(weight);
        t->SetTouchableHandle(track.GetTouchableHandle());
        theTotalResult->AddSecondary(t);
      } 
      else 
      {
        edep += p->GetKineticEnergy();
        delete p;
      }
    }
    theTotalResult->ProposeLocalEnergyDeposit(edep);
    theTotalResult->ProposeNonIonizingEnergyDeposit(edep);
    result->Clear();
  }
  return theTotalResult;
}
 
void 
G4MuNeutrinoNucleusProcess::SetLowestEnergy(G4double val)
{
  lowestEnergy = val;
}