G4ForwardXrayTR.cc

Go to the documentation of this file.

//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
//
// $Id: G4ForwardXrayTR.cc 97385 2016-06-02 09:59:53Z gcosmo $
//
// G4ForwardXrayTR class -- implementation file
//
// History:
// 1st version 11.09.97 V. Grichine (Vladimir.Grichine@cern.ch )
// 2nd version 17.12.97 V. Grichine
// 17-09-01, migration of Materials to pure STL (mma)
// 10-03-03, migration to "cut per region" (V.Ivanchenko)
// 03.06.03, V.Ivanchenko fix compilation warnings

#include "G4ForwardXrayTR.hh"

#include "globals.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "G4Poisson.hh"
#include "G4Material.hh"
#include "G4PhysicsTable.hh"
#include "G4PhysicsVector.hh"
#include "G4PhysicsLinearVector.hh"
#include "G4PhysicsLogVector.hh"
#include "G4ProductionCutsTable.hh"
#include "G4GeometryTolerance.hh"

// Initialization of local constants

G4int    G4ForwardXrayTR::fSympsonNumber =  100;

G4double G4ForwardXrayTR::fTheMinEnergyTR = 1.0*keV;
G4double G4ForwardXrayTR::fTheMaxEnergyTR = 100.0*keV;
G4double G4ForwardXrayTR::fTheMaxAngle    = 1.0e-3;
G4double G4ForwardXrayTR::fTheMinAngle    =  5.0e-6;
G4int    G4ForwardXrayTR::fBinTR          =  50;

G4double G4ForwardXrayTR::fMinProtonTkin = 100.0*GeV;
G4double G4ForwardXrayTR::fMaxProtonTkin = 100.0*TeV;
G4int    G4ForwardXrayTR::fTotBin        =  50;

G4double G4ForwardXrayTR::fPlasmaCof = 4.0*pi*fine_structure_const*
                                       hbarc*hbarc*hbarc/electron_mass_c2;

G4double G4ForwardXrayTR::fCofTR     = fine_structure_const/pi;


//
// Constructor for creation of physics tables (angle and energy TR
// distributions) for a couple of selected materials.
//
// Recommended for use in applications with many materials involved,
// when only few (usually couple) materials are interested for generation
// of TR on the interface between them


G4ForwardXrayTR::
G4ForwardXrayTR( const G4String& matName1,   //  G4Material* pMat1,
         const G4String& matName2,    //  G4Material* pMat2,
                 const G4String& processName                          )
  :        G4TransitionRadiation(processName)
{
  fPtrGamma = nullptr;
  fGammaCutInKineticEnergy = nullptr;
  fGammaTkinCut = fMinEnergyTR = fMaxEnergyTR =  fMaxThetaTR = fGamma = 
    fSigma1 = fSigma2 = 0.0; 
  fAngleDistrTable = nullptr;
  fEnergyDistrTable = nullptr;
  fMatIndex1 = fMatIndex2 = 0;

  // Proton energy vector initialization
  //
  fProtonEnergyVector = new G4PhysicsLogVector(fMinProtonTkin,
                                               fMaxProtonTkin, fTotBin  );
  G4int iMat;
  const G4ProductionCutsTable* theCoupleTable=
        G4ProductionCutsTable::GetProductionCutsTable();
  G4int numOfCouples = theCoupleTable->GetTableSize();

  G4bool build = true;

  for(iMat=0;iMat<numOfCouples;iMat++)    // check first material name
  {
    const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(iMat);
    if( matName1 == couple->GetMaterial()->GetName() )
    {
      fMatIndex1 = couple->GetIndex();
      break;
    }
  }
  if(iMat == numOfCouples)
  {
    G4Exception("G4ForwardXrayTR::G4ForwardXrayTR", "ForwardXrayTR01", JustWarning, "Invalid first material name in G4ForwardXrayTR constructor!");
    build = false;
  }

  if(build) {
    for(iMat=0;iMat<numOfCouples;iMat++)    // check second material name
      {
    const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(iMat);
    if( matName2 == couple->GetMaterial()->GetName() )
      {
        fMatIndex2 = couple->GetIndex();
        break;
      }
      }
    if(iMat == numOfCouples)
      {
        G4Exception("G4ForwardXrayTR::G4ForwardXrayTR", "ForwardXrayTR02", JustWarning, "Invalid second material name in G4ForwardXrayTR constructor!");
    build = false;
      }
  }
  //  G4cout<<"G4ForwardXray constructor is called"<<G4endl;
  if(build) { BuildXrayTRtables(); }
}

//
// Constructor used by X-ray transition radiation parametrisation models

G4ForwardXrayTR::
G4ForwardXrayTR( const G4String& processName  )
   :        G4TransitionRadiation(processName)
{
  fPtrGamma = nullptr;
  fGammaCutInKineticEnergy = nullptr;
  fGammaTkinCut = fMinEnergyTR = fMaxEnergyTR =  fMaxThetaTR = fGamma = 
    fSigma1 = fSigma2 = 0.0; 
  fAngleDistrTable = nullptr;
  fEnergyDistrTable = nullptr;
  fMatIndex1 = fMatIndex2 = 0;

  // Proton energy vector initialization
  //
  fProtonEnergyVector = new G4PhysicsLogVector(fMinProtonTkin,
                                               fMaxProtonTkin, fTotBin  );
}


//
// Destructor
//

G4ForwardXrayTR::~G4ForwardXrayTR()
{
  delete fAngleDistrTable;
  delete fEnergyDistrTable;
  delete fProtonEnergyVector;
}

G4double G4ForwardXrayTR::GetMeanFreePath(const G4Track&,
                      G4double,
                      G4ForceCondition* condition)
{
  *condition = Forced;
  return DBL_MAX;      // so TR doesn't limit mean free path
}

//
// Build physics tables for energy and angular distributions of X-ray TR photon

void G4ForwardXrayTR::BuildXrayTRtables()
{
  G4int iMat, jMat, iTkin, iTR, iPlace;
  const G4ProductionCutsTable* theCoupleTable=
        G4ProductionCutsTable::GetProductionCutsTable();
  G4int numOfCouples = theCoupleTable->GetTableSize();

  fGammaCutInKineticEnergy = theCoupleTable->GetEnergyCutsVector(idxG4GammaCut);

  fAngleDistrTable  = new G4PhysicsTable(2*fTotBin);
  fEnergyDistrTable = new G4PhysicsTable(2*fTotBin);


  for(iMat=0;iMat<numOfCouples;iMat++)     // loop over pairs of different materials
  {
    if( iMat != fMatIndex1 && iMat != fMatIndex2 ) continue;

    for(jMat=0;jMat<numOfCouples;jMat++)  // transition iMat -> jMat !!!
    {
      if( iMat == jMat || ( jMat != fMatIndex1 && jMat != fMatIndex2 ) )
      {
        continue;
      }
      else
      {
        const G4MaterialCutsCouple* iCouple = theCoupleTable->GetMaterialCutsCouple(iMat);
        const G4MaterialCutsCouple* jCouple = theCoupleTable->GetMaterialCutsCouple(jMat);
        const G4Material* mat1 = iCouple->GetMaterial();
        const G4Material* mat2 = jCouple->GetMaterial();

        fSigma1 = fPlasmaCof*(mat1->GetElectronDensity());
        fSigma2 = fPlasmaCof*(mat2->GetElectronDensity());

        // fGammaTkinCut = fGammaCutInKineticEnergy[jMat]; // TR photon in jMat !

        fGammaTkinCut = 0.0;

        if(fGammaTkinCut > fTheMinEnergyTR)    // setting of min/max TR energies
    {
          fMinEnergyTR = fGammaTkinCut;
    }
        else
    {
          fMinEnergyTR = fTheMinEnergyTR;
    }
        if(fGammaTkinCut > fTheMaxEnergyTR)
    {
          fMaxEnergyTR = 2.0*fGammaTkinCut;    // usually very low TR rate
    }
        else
    {
          fMaxEnergyTR = fTheMaxEnergyTR;
    }
        for(iTkin=0;iTkin<fTotBin;iTkin++)      // Lorentz factor loop
    {
          G4PhysicsLogVector*
                    energyVector = new G4PhysicsLogVector( fMinEnergyTR,
                                                           fMaxEnergyTR,
                                                           fBinTR         );

          fGamma = 1.0 +   (fProtonEnergyVector->
                            GetLowEdgeEnergy(iTkin)/proton_mass_c2);

          fMaxThetaTR = 10000.0/(fGamma*fGamma);

          if(fMaxThetaTR > fTheMaxAngle)
          {
            fMaxThetaTR = fTheMaxAngle;
      }
          else
      {
            if(fMaxThetaTR < fTheMinAngle)
        {
              fMaxThetaTR = fTheMinAngle;
        }
      }
   // G4cout<<G4endl<<"fGamma = "<<fGamma<<"  fMaxThetaTR = "<<fMaxThetaTR<<G4endl;
          G4PhysicsLinearVector*
                     angleVector = new G4PhysicsLinearVector(        0.0,
                                                             fMaxThetaTR,
                                                                  fBinTR  );
          G4double energySum = 0.0;
          G4double angleSum  = 0.0;

          energyVector->PutValue(fBinTR-1,energySum);
          angleVector->PutValue(fBinTR-1,angleSum);

          for(iTR=fBinTR-2;iTR>=0;iTR--)
      {
            energySum += fCofTR*EnergySum(energyVector->GetLowEdgeEnergy(iTR),
                                        energyVector->GetLowEdgeEnergy(iTR+1));

            angleSum  += fCofTR*AngleSum(angleVector->GetLowEdgeEnergy(iTR),
                                         angleVector->GetLowEdgeEnergy(iTR+1));

            energyVector->PutValue(iTR,energySum);
            angleVector ->PutValue(iTR,angleSum);
      }
      // G4cout<<"sumE = "<<energySum<<"; sumA = "<<angleSum<<G4endl;

          if(jMat < iMat)
      {
            iPlace = fTotBin+iTkin;   // (iMat*(numOfMat-1)+jMat)*
      }
          else   // jMat > iMat right part of matrices (jMat-1) !
      {
            iPlace = iTkin;  // (iMat*(numOfMat-1)+jMat-1)*fTotBin+
      }
          fEnergyDistrTable->insertAt(iPlace,energyVector);
          fAngleDistrTable->insertAt(iPlace,angleVector);
    }    //                      iTkin
      }      //         jMat != iMat
    }        //     jMat
  }          // iMat
  //  G4cout<<"G4ForwardXrayTR::BuildXrayTRtables have been called"<<G4endl;
}

//
// This function returns the spectral and angle density of TR quanta
// in X-ray energy region generated forward when a relativistic
// charged particle crosses interface between two materials.
// The high energy small theta approximation is applied.
// (matter1 -> matter2)
// varAngle =2* (1 - std::cos(Theta)) or approximately = Theta*Theta
//

G4double
G4ForwardXrayTR::SpectralAngleTRdensity( G4double energy,
                                         G4double varAngle ) const
{
  G4double  formationLength1, formationLength2;
  formationLength1 = 1.0/
  (1.0/(fGamma*fGamma)
  + fSigma1/(energy*energy)
  + varAngle);
  formationLength2 = 1.0/
  (1.0/(fGamma*fGamma)
  + fSigma2/(energy*energy)
  + varAngle);
  return (varAngle/energy)*(formationLength1 - formationLength2)
              *(formationLength1 - formationLength2);

}


//
// Analytical formula for angular density of X-ray TR photons
//

G4double G4ForwardXrayTR::AngleDensity( G4double energy,
                                        G4double varAngle ) const
{
  G4double x, x2, /*a, b,*/ c, d, f, a2, b2, a4, b4;
  G4double cof1, cof2, cof3;
  x = 1.0/energy;
  x2 = x*x;
  c = 1.0/fSigma1;
  d = 1.0/fSigma2;
  f = (varAngle + 1.0/(fGamma*fGamma));
  a2 = c*f;
  b2 = d*f;
  a4 = a2*a2;
  b4 = b2*b2;
  //a = std::sqrt(a2);
  // b = std::sqrt(b2);
  cof1 = c*c*(0.5/(a2*(x2 +a2)) +0.5*std::log(x2/(x2 +a2))/a4);
  cof3 = d*d*(0.5/(b2*(x2 +b2)) +0.5*std::log(x2/(x2 +b2))/b4);
  cof2 = -c*d*(std::log(x2/(x2 +b2))/b2 - std::log(x2/(x2 +a2))/a2)/(a2 - b2)  ;
  return -varAngle*(cof1 + cof2 + cof3);
}

//
// Definite integral of X-ray TR spectral-angle density from energy1
// to energy2
//

G4double G4ForwardXrayTR::EnergyInterval( G4double energy1,
                                          G4double energy2,
                                          G4double varAngle ) const
{
  return     AngleDensity(energy2,varAngle)
           - AngleDensity(energy1,varAngle);
}

//
// Integral angle distribution of X-ray TR photons based on analytical
// formula for angle density
//

G4double G4ForwardXrayTR::AngleSum( G4double varAngle1,
                                    G4double varAngle2     )   const
{
  G4int i;
  G4double h , sumEven = 0.0 , sumOdd = 0.0;
  h = 0.5*(varAngle2 - varAngle1)/fSympsonNumber;
  for(i=1;i<fSympsonNumber;i++)
  {
   sumEven += EnergyInterval(fMinEnergyTR,fMaxEnergyTR,varAngle1 + 2*i*h   );
   sumOdd  += EnergyInterval(fMinEnergyTR,fMaxEnergyTR,
                                                   varAngle1 + (2*i - 1)*h );
  }
  sumOdd += EnergyInterval(fMinEnergyTR,fMaxEnergyTR,
                        varAngle1 + (2*fSympsonNumber - 1)*h    );

  return h*(EnergyInterval(fMinEnergyTR,fMaxEnergyTR,varAngle1)
          + EnergyInterval(fMinEnergyTR,fMaxEnergyTR,varAngle2)
          + 4.0*sumOdd + 2.0*sumEven                          )/3.0;
}

//
// Analytical Expression for   spectral density of Xray TR photons
// x = 2*(1 - std::cos(Theta)) ~ Theta^2
//

G4double G4ForwardXrayTR::SpectralDensity( G4double energy,
                                           G4double      x  ) const
{
  G4double a, b;
  a =  1.0/(fGamma*fGamma)
     + fSigma1/(energy*energy) ;
  b =  1.0/(fGamma*fGamma)
     + fSigma2/(energy*energy) ;
  return ( (a + b)*std::log((x + b)/(x + a))/(a - b)
          + a/(x + a) + b/(x + b) )/energy;

}

//
//  The spectral density in some angle interval from varAngle1 to
//  varAngle2
//

G4double G4ForwardXrayTR::AngleInterval( G4double    energy,
                                         G4double varAngle1,
                                         G4double varAngle2   ) const
{
  return     SpectralDensity(energy,varAngle2)
           - SpectralDensity(energy,varAngle1);
}

//
// Integral spectral distribution of X-ray TR photons based on
// analytical formula for spectral density
//

G4double G4ForwardXrayTR::EnergySum( G4double energy1,
                                     G4double energy2     )   const
{
  G4int i;
  G4double h , sumEven = 0.0 , sumOdd = 0.0;
  h = 0.5*(energy2 - energy1)/fSympsonNumber;
  for(i=1;i<fSympsonNumber;i++)
  {
   sumEven += AngleInterval(energy1 + 2*i*h,0.0,fMaxThetaTR);
   sumOdd  += AngleInterval(energy1 + (2*i - 1)*h,0.0,fMaxThetaTR);
  }
  sumOdd += AngleInterval(energy1 + (2*fSympsonNumber - 1)*h,
                          0.0,fMaxThetaTR);

  return h*(  AngleInterval(energy1,0.0,fMaxThetaTR)
            + AngleInterval(energy2,0.0,fMaxThetaTR)
            + 4.0*sumOdd + 2.0*sumEven                          )/3.0;
}

//
// PostStepDoIt function for creation of forward X-ray photons in TR process
// on boubndary between two materials with really different plasma energies
//

G4VParticleChange* G4ForwardXrayTR::PostStepDoIt(const G4Track& aTrack,
                                const G4Step&  aStep)
{
  aParticleChange.Initialize(aTrack);
  //  G4cout<<"call G4ForwardXrayTR::PostStepDoIt"<<G4endl;
  G4int iMat, jMat, iTkin, iPlace, numOfTR, iTR, iTransfer;

  G4double energyPos, anglePos, energyTR, theta, phi, dirX, dirY, dirZ;
  G4double W, W1, W2, E1, E2;

  G4StepPoint* pPreStepPoint  = aStep.GetPreStepPoint();
  G4StepPoint* pPostStepPoint = aStep.GetPostStepPoint();
  G4double tol=0.5*G4GeometryTolerance::GetInstance()->GetSurfaceTolerance();

  if (pPostStepPoint->GetStepStatus() != fGeomBoundary)
  {
    return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
  }
  if (aTrack.GetStepLength() <= tol)
  {
    return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
  }
  // Come on boundary, so begin to try TR

  const G4MaterialCutsCouple* iCouple = pPreStepPoint ->GetPhysicalVolume()->
             GetLogicalVolume()->GetMaterialCutsCouple();
  const G4MaterialCutsCouple* jCouple = pPostStepPoint ->GetPhysicalVolume()->
             GetLogicalVolume()->GetMaterialCutsCouple();
  const G4Material* iMaterial = iCouple->GetMaterial();
  const G4Material* jMaterial = jCouple->GetMaterial();
  iMat = iCouple->GetIndex();
  jMat = jCouple->GetIndex();

  // The case of equal or approximate (in terms of plasma energy) materials
  // No TR photons ?!

  if (     iMat == jMat
      || (    (fMatIndex1 >= 0 && fMatIndex2 >= 0)
           && ( iMat != fMatIndex1 && iMat != fMatIndex2 )
           && ( jMat != fMatIndex1 && jMat != fMatIndex2 )  )

      || iMaterial->GetState() == jMaterial->GetState()

      ||(iMaterial->GetState() == kStateSolid && jMaterial->GetState() == kStateLiquid )

      ||(iMaterial->GetState() == kStateLiquid && jMaterial->GetState() == kStateSolid  )   )
  {
    return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
  }

  const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
  G4double charge = aParticle->GetDefinition()->GetPDGCharge();

  if(charge == 0.0) // Uncharged particle doesn't Generate TR photons
  {
    return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
  }
  // Now we are ready to Generate TR photons

  G4double chargeSq = charge*charge;
  G4double kinEnergy     = aParticle->GetKineticEnergy();
  G4double massRatio = proton_mass_c2/aParticle->GetDefinition()->GetPDGMass();
  G4double TkinScaled = kinEnergy*massRatio;
  for(iTkin=0;iTkin<fTotBin;iTkin++)
  {
    if(TkinScaled < fProtonEnergyVector->GetLowEdgeEnergy(iTkin)) // <= ?
    {
      break;
    }
  }
  if(jMat < iMat)
  {
    iPlace = fTotBin + iTkin - 1; // (iMat*(numOfMat - 1) + jMat)*
  }
  else
  {
    iPlace = iTkin - 1;  // (iMat*(numOfMat - 1) + jMat - 1)*fTotBin +
  }
  //  G4PhysicsVector*  energyVector1 = (*fEnergyDistrTable)(iPlace)    ;
  //  G4PhysicsVector*  energyVector2 = (*fEnergyDistrTable)(iPlace + 1);

  //  G4PhysicsVector*   angleVector1 = (*fAngleDistrTable)(iPlace)     ;
  //  G4PhysicsVector*   angleVector2 = (*fAngleDistrTable)(iPlace + 1) ;

  G4ParticleMomentum particleDir = aParticle->GetMomentumDirection();

  if(iTkin == fTotBin)                 // TR plato, try from left
  {
 // G4cout<<iTkin<<" mean TR number = "<<( (*(*fEnergyDistrTable)(iPlace))(0) +
 //                                   (*(*fAngleDistrTable)(iPlace))(0) )
 //      *chargeSq*0.5<<G4endl;

    numOfTR = G4Poisson( ( (*(*fEnergyDistrTable)(iPlace))(0) +
                           (*(*fAngleDistrTable)(iPlace))(0) )
                         *chargeSq*0.5 );
    if(numOfTR == 0)
    {
      return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
    }
    else
    {
      // G4cout<<"Number of X-ray TR photons = "<<numOfTR<<G4endl;

      aParticleChange.SetNumberOfSecondaries(numOfTR);

      for(iTR=0;iTR<numOfTR;iTR++)
      {
        energyPos = (*(*fEnergyDistrTable)(iPlace))(0)*G4UniformRand();
        for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
    {
          if(energyPos >= (*(*fEnergyDistrTable)(iPlace))(iTransfer)) break;
    }
        energyTR = (*fEnergyDistrTable)(iPlace)->GetLowEdgeEnergy(iTransfer);

    // G4cout<<"energyTR = "<<energyTR/keV<<"keV"<<G4endl;

        kinEnergy -= energyTR;
        aParticleChange.ProposeEnergy(kinEnergy);

        anglePos = (*(*fAngleDistrTable)(iPlace))(0)*G4UniformRand();
        for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
    {
          if(anglePos > (*(*fAngleDistrTable)(iPlace))(iTransfer)) break;
    }
        theta = std::sqrt((*fAngleDistrTable)(iPlace)->GetLowEdgeEnergy(iTransfer-1));

    // G4cout<<iTransfer<<" :  theta = "<<theta<<G4endl;

        phi = twopi*G4UniformRand();
        dirX = std::sin(theta)*std::cos(phi) ;
        dirY = std::sin(theta)*std::sin(phi) ;
        dirZ = std::cos(theta)          ;
        G4ThreeVector directionTR(dirX,dirY,dirZ);
        directionTR.rotateUz(particleDir);
        G4DynamicParticle* aPhotonTR = new G4DynamicParticle(G4Gamma::Gamma(),
                                                             directionTR,
                                                             energyTR     );
        aParticleChange.AddSecondary(aPhotonTR);
      }
    }
  }
  else
  {
    if(iTkin == 0) // Tkin is too small, neglect of TR photon generation
    {
      return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
    }
    else          // general case: Tkin between two vectors of the material
    {
      E1 = fProtonEnergyVector->GetLowEdgeEnergy(iTkin - 1);
      E2 = fProtonEnergyVector->GetLowEdgeEnergy(iTkin)    ;
       W = 1.0/(E2 - E1);
      W1 = (E2 - TkinScaled)*W;
      W2 = (TkinScaled - E1)*W;

  // G4cout<<iTkin<<" mean TR number = "<<(((*(*fEnergyDistrTable)(iPlace))(0)+
  // (*(*fAngleDistrTable)(iPlace))(0))*W1 +
  //                                ((*(*fEnergyDistrTable)(iPlace + 1))(0)+
  // (*(*fAngleDistrTable)(iPlace + 1))(0))*W2)
  //                                    *chargeSq*0.5<<G4endl;

      numOfTR = G4Poisson((((*(*fEnergyDistrTable)(iPlace))(0)+
                            (*(*fAngleDistrTable)(iPlace))(0))*W1 +
                           ((*(*fEnergyDistrTable)(iPlace + 1))(0)+
                            (*(*fAngleDistrTable)(iPlace + 1))(0))*W2)
                          *chargeSq*0.5 );
      if(numOfTR == 0)
      {
        return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
      }
      else
      {
        // G4cout<<"Number of X-ray TR photons = "<<numOfTR<<G4endl;

        aParticleChange.SetNumberOfSecondaries(numOfTR);
        for(iTR=0;iTR<numOfTR;iTR++)
        {
          energyPos = ((*(*fEnergyDistrTable)(iPlace))(0)*W1+
                       (*(*fEnergyDistrTable)(iPlace + 1))(0)*W2)*G4UniformRand();
          for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
      {
            if(energyPos >= ((*(*fEnergyDistrTable)(iPlace))(iTransfer)*W1+
                       (*(*fEnergyDistrTable)(iPlace + 1))(iTransfer)*W2)) break;
      }
          energyTR = ((*fEnergyDistrTable)(iPlace)->GetLowEdgeEnergy(iTransfer))*W1+
               ((*fEnergyDistrTable)(iPlace + 1)->GetLowEdgeEnergy(iTransfer))*W2;

      // G4cout<<"energyTR = "<<energyTR/keV<<"keV"<<G4endl;

          kinEnergy -= energyTR;
          aParticleChange.ProposeEnergy(kinEnergy);

          anglePos = ((*(*fAngleDistrTable)(iPlace))(0)*W1+
                       (*(*fAngleDistrTable)(iPlace + 1))(0)*W2)*G4UniformRand();
          for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
      {
            if(anglePos > ((*(*fAngleDistrTable)(iPlace))(iTransfer)*W1+
                      (*(*fAngleDistrTable)(iPlace + 1))(iTransfer)*W2)) break;
      }
          theta = std::sqrt(((*fAngleDistrTable)(iPlace)->
                        GetLowEdgeEnergy(iTransfer-1))*W1+
                  ((*fAngleDistrTable)(iPlace + 1)->
                        GetLowEdgeEnergy(iTransfer-1))*W2);

      // G4cout<<iTransfer<<" : theta = "<<theta<<G4endl;

          phi = twopi*G4UniformRand();
          dirX = std::sin(theta)*std::cos(phi) ;
          dirY = std::sin(theta)*std::sin(phi) ;
          dirZ = std::cos(theta)          ;
          G4ThreeVector directionTR(dirX,dirY,dirZ);
          directionTR.rotateUz(particleDir);
          G4DynamicParticle* aPhotonTR = new G4DynamicParticle(G4Gamma::Gamma(),
                                                               directionTR,
                                                               energyTR     );
          aParticleChange.AddSecondary(aPhotonTR);
        }
      }
    }
  }
  return &aParticleChange;
}

//
// Test function for checking of PostStepDoIt random preparation of TR photon
// energy
//

G4double
G4ForwardXrayTR::GetEnergyTR(G4int iMat, G4int jMat, G4int iTkin) const
{
  G4int  iPlace, numOfTR, iTR, iTransfer;
  G4double energyTR = 0.0; // return this value for no TR photons
  G4double energyPos ;
  G4double  W1, W2;

  const G4ProductionCutsTable* theCoupleTable=
        G4ProductionCutsTable::GetProductionCutsTable();
  G4int numOfCouples = theCoupleTable->GetTableSize();

  // The case of equal or approximate (in terms of plasma energy) materials
  // No TR photons ?!

  const G4MaterialCutsCouple* iCouple = theCoupleTable->GetMaterialCutsCouple(iMat);
  const G4MaterialCutsCouple* jCouple = theCoupleTable->GetMaterialCutsCouple(jMat);
  const G4Material* iMaterial = iCouple->GetMaterial();
  const G4Material* jMaterial = jCouple->GetMaterial();

  if (     iMat == jMat

      || iMaterial->GetState() == jMaterial->GetState()

      ||(iMaterial->GetState() == kStateSolid && jMaterial->GetState() == kStateLiquid )

      ||(iMaterial->GetState() == kStateLiquid && jMaterial->GetState() == kStateSolid  )   )

  {
    return energyTR;
  }

  if(jMat < iMat)
  {
    iPlace = (iMat*(numOfCouples - 1) + jMat)*fTotBin + iTkin - 1;
  }
  else
  {
    iPlace = (iMat*(numOfCouples - 1) + jMat - 1)*fTotBin + iTkin - 1;
  }
  G4PhysicsVector*  energyVector1 = (*fEnergyDistrTable)(iPlace)    ;
  G4PhysicsVector*  energyVector2 = (*fEnergyDistrTable)(iPlace + 1);

  if(iTkin == fTotBin)                 // TR plato, try from left
  {
    numOfTR = G4Poisson( (*energyVector1)(0)  );
    if(numOfTR == 0)
    {
      return energyTR;
    }
    else
    {
      for(iTR=0;iTR<numOfTR;iTR++)
      {
        energyPos = (*energyVector1)(0)*G4UniformRand();
        for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
    {
          if(energyPos >= (*energyVector1)(iTransfer)) break;
    }
        energyTR += energyVector1->GetLowEdgeEnergy(iTransfer);
      }
    }
  }
  else
  {
    if(iTkin == 0) // Tkin is too small, neglect of TR photon generation
    {
      return energyTR;
    }
    else          // general case: Tkin between two vectors of the material
    {             // use trivial mean half/half
      W1 = 0.5;
      W2 = 0.5;
     numOfTR = G4Poisson( (*energyVector1)(0)*W1 +
                          (*energyVector2)(0)*W2  );
      if(numOfTR == 0)
      {
        return energyTR;
      }
      else
      {
  G4cout<<"It is still OK in GetEnergyTR(int,int,int)"<<G4endl;
        for(iTR=0;iTR<numOfTR;iTR++)
        {
          energyPos = ((*energyVector1)(0)*W1+
                       (*energyVector2)(0)*W2)*G4UniformRand();
          for(iTransfer=0;iTransfer<fBinTR-1;iTransfer++)
      {
            if(energyPos >= ((*energyVector1)(iTransfer)*W1+
                             (*energyVector2)(iTransfer)*W2)) break;
      }
          energyTR += (energyVector1->GetLowEdgeEnergy(iTransfer))*W1+
                      (energyVector2->GetLowEdgeEnergy(iTransfer))*W2;

        }
      }
    }
  }

  return energyTR;
}

//
// Test function for checking of PostStepDoIt random preparation of TR photon
// theta angle relative to particle direction
//


G4double
G4ForwardXrayTR::GetThetaTR(G4int, G4int, G4int) const
{
  G4double theta = 0.0;

  return theta;
}



// end of G4ForwardXrayTR implementation file
//