G4PAIPhotModel.cc

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// -------------------------------------------------------------------
//
// GEANT4 Class
// File name:     G4PAIPhotModel.cc
//
// Author: [email protected] on base of G4PAIModel MT interface
//
// Creation date: 07.10.2013
//
// Modifications:
//
//
 
#include "G4PAIPhotModel.hh"
 
#include "G4SystemOfUnits.hh"
#include "G4PhysicalConstants.hh"
#include "G4Region.hh"
#include "G4ProductionCutsTable.hh"
#include "G4MaterialCutsCouple.hh"
#include "G4MaterialTable.hh"
#include "G4RegionStore.hh"
 
#include "Randomize.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4Gamma.hh"
#include "G4Poisson.hh"
#include "G4Step.hh"
#include "G4Material.hh"
#include "G4DynamicParticle.hh"
#include "G4ParticleDefinition.hh"
#include "G4ParticleChangeForLoss.hh"
#include "G4PAIPhotData.hh"
#include "G4DeltaAngle.hh"
 
////////////////////////////////////////////////////////////////////////
 
using namespace std;
 
G4PAIPhotModel::G4PAIPhotModel(const G4ParticleDefinition* p, const G4String& nam)
  : G4VEmModel(nam),G4VEmFluctuationModel(nam),
    fVerbose(0),
    fModelData(nullptr),
    fParticle(nullptr)
{  
  fElectron = G4Electron::Electron();
  fPositron = G4Positron::Positron();
 
  fParticleChange = nullptr;
 
  if(p) { SetParticle(p); }
  else  { SetParticle(fElectron); }
 
  // default generator
  SetAngularDistribution(new G4DeltaAngle());
  fLowestTcut = 12.5*CLHEP::eV;
}
 
////////////////////////////////////////////////////////////////////////////
 
G4PAIPhotModel::~G4PAIPhotModel()
{
  if(IsMaster()) { delete fModelData; fModelData = nullptr; }
}
 
////////////////////////////////////////////////////////////////////////////
 
void G4PAIPhotModel::Initialise(const G4ParticleDefinition* p,
                    const G4DataVector& cuts)
{
  if(fVerbose > 1) 
  {
    G4cout<<"G4PAIPhotModel::Initialise for "<<p->GetParticleName()<<G4endl;
  }
  SetParticle(p);
  fParticleChange = GetParticleChangeForLoss();
 
  if( IsMaster() ) 
  { 
    delete fModelData;
    fMaterialCutsCoupleVector.clear(); 
 
    G4double tmin = LowEnergyLimit()*fRatio;
    G4double tmax = HighEnergyLimit()*fRatio;
    fModelData = new G4PAIPhotData(tmin, tmax, fVerbose);
    
    // Prepare initialization
    const G4MaterialTable* theMaterialTable = G4Material::GetMaterialTable();
    size_t numOfMat   = G4Material::GetNumberOfMaterials();
    size_t numRegions = fPAIRegionVector.size();
 
    // protect for unit tests
    if(0 == numRegions) {
      G4Exception("G4PAIModel::Initialise()","em0106",JustWarning,
                  "no G4Regions are registered for the PAI model - World is used");
      fPAIRegionVector.push_back(G4RegionStore::GetInstance()
                 ->GetRegion("DefaultRegionForTheWorld", false));
      numRegions = 1;
    }
 
    for( size_t iReg = 0; iReg < numRegions; ++iReg ) 
    {
      const G4Region* curReg = fPAIRegionVector[iReg];
      G4Region* reg = const_cast<G4Region*>(curReg);
 
      for(size_t jMat = 0; jMat < numOfMat; ++jMat) 
      {
    G4Material* mat = (*theMaterialTable)[jMat];
    const G4MaterialCutsCouple* cutCouple = reg->FindCouple(mat);
    if(nullptr != cutCouple) 
        {
      if(fVerbose > 1)
      {
        G4cout << "Reg <" <<curReg->GetName() << ">  mat <" 
        << mat->GetName() << ">  fCouple= " 
        << cutCouple << ", idx= " << cutCouple->GetIndex()
        <<"  " << p->GetParticleName() 
        <<", cuts.size() = " << cuts.size() << G4endl;
      }
      // check if this couple is not already initialized
 
      size_t n = fMaterialCutsCoupleVector.size();
 
      G4bool isnew = true;
      if( 0 < n ) 
          {
        for(size_t i=0; i<fMaterialCutsCoupleVector.size(); ++i) 
            {
          if(cutCouple == fMaterialCutsCoupleVector[i]) {
        isnew = false;
        break;
          }
        }
      }
      // initialise data banks
      if(isnew) {
        fMaterialCutsCoupleVector.push_back(cutCouple);
        G4double deltaCutInKinEnergy = cuts[cutCouple->GetIndex()];
        fModelData->Initialise(cutCouple, deltaCutInKinEnergy, this);
      }
    }
      }
    }
    InitialiseElementSelectors(p, cuts);
  }
}
 
/////////////////////////////////////////////////////////////////////////
 
void G4PAIPhotModel::InitialiseLocal(const G4ParticleDefinition*, 
                 G4VEmModel* masterModel)
{
  fModelData = static_cast<G4PAIPhotModel*>(masterModel)->GetPAIPhotData();
  fMaterialCutsCoupleVector = static_cast<G4PAIPhotModel*>(masterModel)->GetVectorOfCouples();
  SetElementSelectors( masterModel->GetElementSelectors() );
}
 
//////////////////////////////////////////////////////////////////////////////
 
G4double G4PAIPhotModel::MinEnergyCut(const G4ParticleDefinition*,
                      const G4MaterialCutsCouple*)
{
  return fLowestTcut;
}
 
//////////////////////////////////////////////////////////////////////////////
 
G4double G4PAIPhotModel::ComputeDEDXPerVolume(const G4Material*,
                      const G4ParticleDefinition* p,
                      G4double kineticEnergy,
                      G4double cutEnergy)
{
  G4int coupleIndex = FindCoupleIndex(CurrentCouple());
  if(0 > coupleIndex) { return 0.0; }
 
  G4double cut = std::min(MaxSecondaryEnergy(p, kineticEnergy), cutEnergy);
  G4double scaledTkin = kineticEnergy*fRatio;
  G4double dedx = fChargeSquare*fModelData->DEDXPerVolume(coupleIndex, scaledTkin, cut);
  return dedx;
}
 
/////////////////////////////////////////////////////////////////////////
 
G4double G4PAIPhotModel::CrossSectionPerVolume( const G4Material*,
                        const G4ParticleDefinition* p,
                        G4double kineticEnergy,
                        G4double cutEnergy,
                        G4double maxEnergy  ) 
{
  G4int coupleIndex = FindCoupleIndex(CurrentCouple());
  if(0 > coupleIndex) { return 0.0; } 
 
  G4double tmax = std::min(MaxSecondaryEnergy(p, kineticEnergy), maxEnergy);
  if(tmax <= cutEnergy) { return 0.0; } 
 
  G4double scaledTkin = kineticEnergy*fRatio;
  G4double xs = fChargeSquare*fModelData->CrossSectionPerVolume(coupleIndex,
                                          scaledTkin, cutEnergy, tmax);
  return xs;
}
 
///////////////////////////////////////////////////////////////////////////
//
// It is analog of PostStepDoIt in terms of secondary electron.
//
 
void G4PAIPhotModel::SampleSecondaries(std::vector<G4DynamicParticle*>* vdp,
                   const G4MaterialCutsCouple* matCC,
                   const G4DynamicParticle* dp,
                   G4double tmin,
                   G4double maxEnergy)
{
  G4int coupleIndex = FindCoupleIndex(matCC);
  if(0 > coupleIndex) { return; }
 
  SetParticle(dp->GetDefinition());
 
  G4double kineticEnergy = dp->GetKineticEnergy();
 
  G4double tmax = MaxSecondaryEnergy(fParticle, kineticEnergy);
 
  if( maxEnergy <  tmax) tmax = maxEnergy; 
  if( tmin      >= tmax) return; 
 
  G4ThreeVector direction = dp->GetMomentumDirection();
  G4double scaledTkin     = kineticEnergy*fRatio;
  G4double totalEnergy    = kineticEnergy + fMass;
  G4double totalMomentum  = sqrt(kineticEnergy*(totalEnergy + fMass));
  G4double plRatio        = fModelData->GetPlasmonRatio(coupleIndex, scaledTkin);
 
  if( G4UniformRand() <= plRatio )
  {
    G4double deltaTkin = fModelData->SamplePostStepPlasmonTransfer(coupleIndex, scaledTkin);
 
    // G4cout<<"G4PAIPhotModel::SampleSecondaries; dp "<<dp->GetParticleDefinition()->GetParticleName()
    // <<"; Tkin = "<<kineticEnergy/keV<<" keV; transfer = "<<deltaTkin/keV<<" keV "<<G4endl;
 
    if( deltaTkin <= 0. && fVerbose > 0) 
    {
      G4cout<<"G4PAIPhotModel::SampleSecondary e- deltaTkin = "<<deltaTkin<<G4endl;
    }
    if( deltaTkin <= 0.) { return; } 
 
    if( deltaTkin > tmax) { deltaTkin = tmax; }
 
    const G4Element* anElement = SelectTargetAtom(matCC,fParticle,kineticEnergy,
                                                  dp->GetLogKineticEnergy());
    G4int Z = anElement->GetZasInt();
 
    auto deltaRay = new G4DynamicParticle(fElectron,
        GetAngularDistribution()->SampleDirection(dp, deltaTkin,
                              Z, matCC->GetMaterial()),
                              deltaTkin);
 
    // primary change
 
    kineticEnergy -= deltaTkin;
 
    if( kineticEnergy <= 0. ) // kill primary as local? energy deposition
    {
      fParticleChange->SetProposedKineticEnergy(0.0);
      fParticleChange->ProposeLocalEnergyDeposit(kineticEnergy+deltaTkin);
      return; 
    }
    else
    {
      G4ThreeVector dir = totalMomentum*direction - deltaRay->GetMomentum();
      direction = dir.unit();
      fParticleChange->SetProposedKineticEnergy(kineticEnergy);
      fParticleChange->SetProposedMomentumDirection(direction);
      vdp->push_back(deltaRay);
    }
  }
  else // secondary X-ray CR photon
  {
    G4double deltaTkin     = fModelData->SamplePostStepPhotonTransfer(coupleIndex, scaledTkin);
 
    //  G4cout<<"PAIPhotonModel PhotonPostStepTransfer = "<<deltaTkin/keV<<" keV"<<G4endl; 
 
    if( deltaTkin <= 0. )
    {
      G4cout<<"G4PAIPhotonModel::SampleSecondary gamma deltaTkin = "<<deltaTkin<<G4endl;
    }
    if( deltaTkin <= 0.) return;
 
    if( deltaTkin >= kineticEnergy ) // stop primary
    {
      deltaTkin = kineticEnergy;
      kineticEnergy = 0.0;
    }
    G4double costheta = 0.; // G4UniformRand(); // VG: ??? for start only
    G4double sintheta = sqrt((1.+costheta)*(1.-costheta));
 
    //  direction of the 'Cherenkov' photon  
    G4double phi = twopi*G4UniformRand(); 
    G4double dirx = sintheta*cos(phi), diry = sintheta*sin(phi), dirz = costheta;
 
    G4ThreeVector deltaDirection(dirx,diry,dirz);
    deltaDirection.rotateUz(direction);
 
    if( kineticEnergy > 0.) // primary change
    {
      kineticEnergy -= deltaTkin;
      fParticleChange->SetProposedKineticEnergy(kineticEnergy);
    }
    else // stop primary, but pass X-ray CR
    {
      // fParticleChange->ProposeLocalEnergyDeposit(deltaTkin);
      fParticleChange->SetProposedKineticEnergy(0.0);
    }
    // create G4DynamicParticle object for photon ray
 
    auto photonRay = new G4DynamicParticle;
    photonRay->SetDefinition( G4Gamma::Gamma() );
    photonRay->SetKineticEnergy( deltaTkin );
    photonRay->SetMomentumDirection(deltaDirection); 
 
    vdp->push_back(photonRay);
  }
  return;
}
 
///////////////////////////////////////////////////////////////////////
 
G4double G4PAIPhotModel::SampleFluctuations(
                         const G4MaterialCutsCouple* matCC,
                         const G4DynamicParticle* aParticle,
                         const G4double, const G4double,
                         const G4double step, const G4double eloss)
{
  // return 0.;
  G4int coupleIndex = FindCoupleIndex(matCC);
  if(0 > coupleIndex) { return eloss; }
 
  SetParticle(aParticle->GetDefinition());
 
  // G4cout << "G4PAIPhotModel::SampleFluctuations step(mm)= "<< step/mm
  // << "  Eloss(keV)= " << eloss/keV  << " in " 
  // << matCC->GetMaterial()->GetName() << G4endl;
 
  G4double Tkin       = aParticle->GetKineticEnergy();
  G4double scaledTkin = Tkin*fRatio;
 
  G4double loss = fModelData->SampleAlongStepPhotonTransfer(coupleIndex, Tkin,
                                    scaledTkin,
                                    step*fChargeSquare);
  loss += fModelData->SampleAlongStepPlasmonTransfer(coupleIndex, Tkin,
                                                     scaledTkin, step*fChargeSquare);
  
  // G4cout<<"  PAIPhotModel::SampleFluctuations loss = "<<loss/keV<<" keV, on step = "
  // <<step/mm<<" mm"<<G4endl; 
  return loss;
 
}
 
//////////////////////////////////////////////////////////////////////
//
// Returns the statistical estimation of the energy loss distribution variance
//
 
 
G4double G4PAIPhotModel::Dispersion(const G4Material* material, 
                                    const G4DynamicParticle* aParticle,
                    const G4double tcut,
                    const G4double tmax, 
                        const G4double step)
{
  G4double particleMass  = aParticle->GetMass();
  G4double electronDensity = material->GetElectronDensity();
  G4double kineticEnergy = aParticle->GetKineticEnergy();
  G4double q = aParticle->GetCharge()/eplus;
  G4double etot = kineticEnergy + particleMass;
  G4double beta2 = kineticEnergy*(kineticEnergy + 2.0*particleMass)/(etot*etot);
  G4double siga  = (tmax/beta2 - 0.5*tcut) * twopi_mc2_rcl2 * step
                 * electronDensity * q * q;
 
  return siga;
}
 
/////////////////////////////////////////////////////////////////////
 
G4double G4PAIPhotModel::MaxSecondaryEnergy( const G4ParticleDefinition* p,
                     G4double kinEnergy) 
{
  SetParticle(p);
  G4double tmax = kinEnergy;
  if(p == fElectron) { tmax *= 0.5; }
  else if(p != fPositron) { 
    G4double ratio= electron_mass_c2/fMass;
    G4double gamma= kinEnergy/fMass + 1.0;
    tmax = 2.0*electron_mass_c2*(gamma*gamma - 1.) /
                  (1. + 2.0*gamma*ratio + ratio*ratio);
  }
  return tmax;
}
 
///////////////////////////////////////////////////////////////
 
void G4PAIPhotModel::DefineForRegion(const G4Region* r) 
{
  fPAIRegionVector.push_back(r);
}
 
//
//
/////////////////////////////////////////////////