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// $Id: G4DNARuddIonisationModel.cc,v 1.21 2010/11/04 14:52:17 sincerti Exp $
// GEANT4 tag $Name: geant4-09-04-ref-00 $
//

#include "G4DNARuddIonisationModel.hh"
//#include "G4DynamicMolecule.hh"

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

using namespace std;

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

G4DNARuddIonisationModel::G4DNARuddIonisationModel(const G4ParticleDefinition*,
                                             const G4String& nam)
:G4VEmModel(nam),isInitialised(false)
{
  lowEnergyLimitForZ1 = 0 * eV; 
  lowEnergyLimitForZ2 = 0 * eV; 
  lowEnergyLimitOfModelForZ1 = 100 * eV; 
  lowEnergyLimitOfModelForZ2 = 1 * keV; 
  killBelowEnergyForZ1 = lowEnergyLimitOfModelForZ1; 
  killBelowEnergyForZ2 = lowEnergyLimitOfModelForZ2; 

  verboseLevel= 0;
  // Verbosity scale:
  // 0 = nothing 
  // 1 = warning for energy non-conservation 
  // 2 = details of energy budget
  // 3 = calculation of cross sections, file openings, sampling of atoms
  // 4 = entering in methods
  
  if( verboseLevel>0 ) 
  { 
    G4cout << "Rudd ionisation model is constructed " << G4endl;
  }
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

G4DNARuddIonisationModel::~G4DNARuddIonisationModel()
{  
  // Cross section
  
  std::map< G4String,G4DNACrossSectionDataSet*,std::less<G4String> >::iterator pos;
  for (pos = tableData.begin(); pos != tableData.end(); ++pos)
  {
    G4DNACrossSectionDataSet* table = pos->second;
    delete table;
  }
  
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

void G4DNARuddIonisationModel::Initialise(const G4ParticleDefinition* particle,
                                       const G4DataVector& /*cuts*/)
{

  if (verboseLevel > 3)
    G4cout << "Calling G4DNARuddIonisationModel::Initialise()" << G4endl;

  // Energy limits

  G4String fileProton("dna/sigma_ionisation_p_rudd");
  G4String fileHydrogen("dna/sigma_ionisation_h_rudd");
  G4String fileAlphaPlusPlus("dna/sigma_ionisation_alphaplusplus_rudd");
  G4String fileAlphaPlus("dna/sigma_ionisation_alphaplus_rudd");
  G4String fileHelium("dna/sigma_ionisation_he_rudd");

  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();
  G4ParticleDefinition* protonDef = G4Proton::ProtonDefinition();
  G4ParticleDefinition* hydrogenDef = instance->GetIon("hydrogen");
  G4ParticleDefinition* alphaPlusPlusDef = instance->GetIon("alpha++");
  G4ParticleDefinition* alphaPlusDef = instance->GetIon("alpha+");
  G4ParticleDefinition* heliumDef = instance->GetIon("helium");

  G4String proton;
  G4String hydrogen;
  G4String alphaPlusPlus;
  G4String alphaPlus;
  G4String helium;

  G4double scaleFactor = 1 * m*m;

  if (protonDef != 0)
  {
    proton = protonDef->GetParticleName();
    tableFile[proton] = fileProton;

    lowEnergyLimit[proton] = lowEnergyLimitForZ1;
    highEnergyLimit[proton] = 500. * keV;

    // Cross section

    G4DNACrossSectionDataSet* tableProton = new G4DNACrossSectionDataSet(new G4LogLogInterpolation, 
									   eV,
									   scaleFactor );
    tableProton->LoadData(fileProton);
    tableData[proton] = tableProton;
  }
  else
  {
    G4Exception("G4DNARuddIonisationModel::Initialise: proton is not defined");
  }

  if (hydrogenDef != 0)
  {
    hydrogen = hydrogenDef->GetParticleName();
    tableFile[hydrogen] = fileHydrogen;

    lowEnergyLimit[hydrogen] = lowEnergyLimitForZ1;
    highEnergyLimit[hydrogen] = 100. * MeV;

    // Cross section

    G4DNACrossSectionDataSet* tableHydrogen = new G4DNACrossSectionDataSet(new G4LogLogInterpolation,
									     eV,
									     scaleFactor );
    tableHydrogen->LoadData(fileHydrogen);
      
    tableData[hydrogen] = tableHydrogen;
  }
  else
  {
    G4Exception("G4DNARuddIonisationModel::Initialise: hydrogen is not defined");
  }

  if (alphaPlusPlusDef != 0)
  {
    alphaPlusPlus = alphaPlusPlusDef->GetParticleName();
    tableFile[alphaPlusPlus] = fileAlphaPlusPlus;

    lowEnergyLimit[alphaPlusPlus] = lowEnergyLimitForZ2;
    highEnergyLimit[alphaPlusPlus] = 400. * MeV;

    // Cross section

    G4DNACrossSectionDataSet* tableAlphaPlusPlus = new G4DNACrossSectionDataSet(new G4LogLogInterpolation, 
										  eV,
										  scaleFactor );
    tableAlphaPlusPlus->LoadData(fileAlphaPlusPlus);
      
    tableData[alphaPlusPlus] = tableAlphaPlusPlus;
  }
  else
  {
    G4Exception("G4DNARuddIonisationModel::Initialise: alphaPlusPlus is not defined");
  }

  if (alphaPlusDef != 0)
  {
    alphaPlus = alphaPlusDef->GetParticleName();
    tableFile[alphaPlus] = fileAlphaPlus;

    lowEnergyLimit[alphaPlus] = lowEnergyLimitForZ2;
    highEnergyLimit[alphaPlus] = 400. * MeV;

    // Cross section

    G4DNACrossSectionDataSet* tableAlphaPlus = new G4DNACrossSectionDataSet(new G4LogLogInterpolation, 
									      eV,
									      scaleFactor );
    tableAlphaPlus->LoadData(fileAlphaPlus);
    tableData[alphaPlus] = tableAlphaPlus;
  }
  else
  {
    G4Exception("G4DNARuddIonisationModel::Initialise: alphaPlus is not defined");
  }

  if (heliumDef != 0)
  {
    helium = heliumDef->GetParticleName();
    tableFile[helium] = fileHelium;

    lowEnergyLimit[helium] = lowEnergyLimitForZ2;
    highEnergyLimit[helium] = 400. * MeV;

    // Cross section

    G4DNACrossSectionDataSet* tableHelium = new G4DNACrossSectionDataSet(new G4LogLogInterpolation, 
									   eV,
									   scaleFactor );
    tableHelium->LoadData(fileHelium);
    tableData[helium] = tableHelium;
    }
  else
  {
    G4Exception("G4DNARuddIonisationModel::Initialise: helium is not defined");
  }

  if (particle==protonDef) 
  {
    SetLowEnergyLimit(lowEnergyLimit[proton]);
    SetHighEnergyLimit(highEnergyLimit[proton]);
  }

  if (particle==hydrogenDef) 
  {
    SetLowEnergyLimit(lowEnergyLimit[hydrogen]);
    SetHighEnergyLimit(highEnergyLimit[hydrogen]);
  }

  if (particle==heliumDef) 
  {
    SetLowEnergyLimit(lowEnergyLimit[helium]);
    SetHighEnergyLimit(highEnergyLimit[helium]);
  }

  if (particle==alphaPlusDef) 
  {
    SetLowEnergyLimit(lowEnergyLimit[alphaPlus]);
    SetHighEnergyLimit(highEnergyLimit[alphaPlus]);
  }

  if (particle==alphaPlusPlusDef) 
  {
    SetLowEnergyLimit(lowEnergyLimit[alphaPlusPlus]);
    SetHighEnergyLimit(highEnergyLimit[alphaPlusPlus]);
  }

  if( verboseLevel>0 ) 
  { 
    G4cout << "Rudd ionisation model is initialized " << G4endl
           << "Energy range: "
           << LowEnergyLimit() / eV << " eV - "
           << HighEnergyLimit() / keV << " keV for "
           << particle->GetParticleName()
           << G4endl;
  }

  //
  
  if(!isInitialised) 
  {
    isInitialised = true;
  
    if(pParticleChange)
      fParticleChangeForGamma = reinterpret_cast<G4ParticleChangeForGamma*>(pParticleChange);
    else
      fParticleChangeForGamma = new G4ParticleChangeForGamma();
  }    

  // InitialiseElementSelectors(particle,cuts);

}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

G4double G4DNARuddIonisationModel::CrossSectionPerVolume(const G4Material* material,
					   const G4ParticleDefinition* particleDefinition,
					   G4double k,
					   G4double,
					   G4double)
{
  if (verboseLevel > 3)
    G4cout << "Calling CrossSectionPerVolume() of G4DNARuddIonisationModel" << G4endl;

 // Calculate total cross section for model

  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  if (
      particleDefinition != G4Proton::ProtonDefinition()
      &&
      particleDefinition != instance->GetIon("hydrogen")
      &&
      particleDefinition != instance->GetIon("alpha++")
      &&
      particleDefinition != instance->GetIon("alpha+")
      &&
      particleDefinition != instance->GetIon("helium")
     )
   	    
    return 0;

  G4double lowLim = 0;
  
  if (     particleDefinition == G4Proton::ProtonDefinition()
       ||  particleDefinition == instance->GetIon("hydrogen")
     )
       
       lowLim = lowEnergyLimitOfModelForZ1;
       
  if (     particleDefinition == instance->GetIon("alpha++")
       ||  particleDefinition == instance->GetIon("alpha+")
       ||  particleDefinition == instance->GetIon("helium")
     )
       
       lowLim = lowEnergyLimitOfModelForZ2;

  G4double highLim = 0;
  G4double sigma=0;

  if (material->GetName() == "G4_WATER")
  {
    const G4String& particleName = particleDefinition->GetParticleName();
    
    // SI - the following is useless since lowLim is already defined 
    /*
    std::map< G4String,G4double,std::less<G4String> >::iterator pos1;
    pos1 = lowEnergyLimit.find(particleName);

    if (pos1 != lowEnergyLimit.end())
    {
      lowLim = pos1->second;
    }
    */

    std::map< G4String,G4double,std::less<G4String> >::iterator pos2;
    pos2 = highEnergyLimit.find(particleName);

    if (pos2 != highEnergyLimit.end())
    {
      highLim = pos2->second;
    }

    if (k < highLim)
    {
      
      //SI : XS must not be zero otherwise sampling of secondaries method ignored

      if (k < lowLim) k = lowLim;

      //      
      
      std::map< G4String,G4DNACrossSectionDataSet*,std::less<G4String> >::iterator pos;
      pos = tableData.find(particleName);
	
      if (pos != tableData.end())
      {
         G4DNACrossSectionDataSet* table = pos->second;
         if (table != 0)
         {
	      sigma = table->FindValue(k);

         }
      }
      else
      {
	G4Exception("G4DNARuddIonisationModel::CrossSectionPerVolume: attempting to calculate cross section for wrong particle");
      }
  
    } // if (k >= lowLim && k < highLim)
    
    if (verboseLevel > 3)
    {
      G4cout << "---> Kinetic energy(eV)=" << k/eV << G4endl;
      G4cout << " - Cross section per water molecule (cm^2)=" << sigma/cm/cm << G4endl;
      G4cout << " - Cross section per water molecule (cm^-1)=" << sigma*
      material->GetAtomicNumDensityVector()[1]/(1./cm) << G4endl;
    } 
 
  } // if (waterMaterial)
 
 return sigma*material->GetAtomicNumDensityVector()[1];		   

}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....

void G4DNARuddIonisationModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect,
					      const G4MaterialCutsCouple* /*couple*/,
					      const G4DynamicParticle* particle,
					      G4double,
					      G4double)
{
  if (verboseLevel > 3)
    G4cout << "Calling SampleSecondaries() of G4DNARuddIonisationModel" << G4endl;

  G4double lowLim = 0;
  G4double highLim = 0;

  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  if (     particle->GetDefinition() == G4Proton::ProtonDefinition()
       ||  particle->GetDefinition() == instance->GetIon("hydrogen")
     )
       
       lowLim = killBelowEnergyForZ1;
       
  if (     particle->GetDefinition() == instance->GetIon("alpha++")
       ||  particle->GetDefinition() == instance->GetIon("alpha+")
       ||  particle->GetDefinition() == instance->GetIon("helium")
     )
       
       lowLim = killBelowEnergyForZ2;

  G4double k = particle->GetKineticEnergy();

  const G4String& particleName = particle->GetDefinition()->GetParticleName();

  // SI - the following is useless since lowLim is already defined 
  /* 
  std::map< G4String,G4double,std::less<G4String> >::iterator pos1;
  pos1 = lowEnergyLimit.find(particleName);

  if (pos1 != lowEnergyLimit.end())
  {
    lowLim = pos1->second;
  }
  */

  std::map< G4String,G4double,std::less<G4String> >::iterator pos2;
  pos2 = highEnergyLimit.find(particleName);

  if (pos2 != highEnergyLimit.end())
  {
    highLim = pos2->second;
  }

  if (k >= lowLim && k < highLim)
  {
      G4ParticleDefinition* definition = particle->GetDefinition();
      G4ParticleMomentum primaryDirection = particle->GetMomentumDirection();
      /*
      G4double particleMass = definition->GetPDGMass();
      G4double totalEnergy = k + particleMass;
      G4double pSquare = k*(totalEnergy+particleMass);
      G4double totalMomentum = std::sqrt(pSquare);
      */

      G4int ionizationShell = RandomSelect(k,particleName);
  
      G4double secondaryKinetic = RandomizeEjectedElectronEnergy(definition,k,ionizationShell);
  
      G4double bindingEnergy = waterStructure.IonisationEnergy(ionizationShell);

      G4double cosTheta = 0.;
      G4double phi = 0.; 
      RandomizeEjectedElectronDirection(definition, k,secondaryKinetic, cosTheta, phi);

      G4double sinTheta = std::sqrt(1.-cosTheta*cosTheta);
      G4double dirX = sinTheta*std::cos(phi);
      G4double dirY = sinTheta*std::sin(phi);
      G4double dirZ = cosTheta;
      G4ThreeVector deltaDirection(dirX,dirY,dirZ);
      deltaDirection.rotateUz(primaryDirection);

      // Ignored for ions on electrons
      /*
      G4double deltaTotalMomentum = std::sqrt(secondaryKinetic*(secondaryKinetic + 2.*electron_mass_c2 ));

      G4double finalPx = totalMomentum*primaryDirection.x() - deltaTotalMomentum*deltaDirection.x();
      G4double finalPy = totalMomentum*primaryDirection.y() - deltaTotalMomentum*deltaDirection.y();
      G4double finalPz = totalMomentum*primaryDirection.z() - deltaTotalMomentum*deltaDirection.z();
      G4double finalMomentum = std::sqrt(finalPx*finalPx+finalPy*finalPy+finalPz*finalPz);
      finalPx /= finalMomentum;
      finalPy /= finalMomentum;
      finalPz /= finalMomentum;

      G4ThreeVector direction;
      direction.set(finalPx,finalPy,finalPz);

      fParticleChangeForGamma->ProposeMomentumDirection(direction.unit()) ;
      */
      fParticleChangeForGamma->ProposeMomentumDirection(primaryDirection);

      fParticleChangeForGamma->SetProposedKineticEnergy(k-bindingEnergy-secondaryKinetic);
      fParticleChangeForGamma->ProposeLocalEnergyDeposit(bindingEnergy);

      G4DynamicParticle* dp = new G4DynamicParticle (G4Electron::Electron(),deltaDirection,secondaryKinetic) ;
      fvect->push_back(dp);

  }

  // SI - not useful since low energy of model is 0 eV
  
  if (k < lowLim) 
  {  
    fParticleChangeForGamma->ProposeTrackStatus(fStopAndKill);
    fParticleChangeForGamma->ProposeLocalEnergyDeposit(k);
  }

}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::RandomizeEjectedElectronEnergy(G4ParticleDefinition* particleDefinition, 
								    G4double k, 
								    G4int shell)
{
  G4double maximumKineticEnergyTransfer = 0.;
 
  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  if (particleDefinition == G4Proton::ProtonDefinition() 
      || particleDefinition == instance->GetIon("hydrogen"))
  { 
      maximumKineticEnergyTransfer= 4.* (electron_mass_c2 / proton_mass_c2) * k;
  }

  if (particleDefinition == instance->GetIon("helium") 
      || particleDefinition == instance->GetIon("alpha+")
      || particleDefinition == instance->GetIon("alpha++"))
  { 
      maximumKineticEnergyTransfer= 4.* (0.511 / 3728) * k;
  }

  G4double crossSectionMaximum = 0.;
  
  for(G4double value=waterStructure.IonisationEnergy(shell); value<=5.*waterStructure.IonisationEnergy(shell) && k>=value ; value+=0.1*eV)
  {
      G4double differentialCrossSection = DifferentialCrossSection(particleDefinition, k, value, shell);
      if(differentialCrossSection >= crossSectionMaximum) crossSectionMaximum = differentialCrossSection;
  }
  
 
  G4double secElecKinetic = 0.;
  
  do
  {
    secElecKinetic = G4UniformRand() * maximumKineticEnergyTransfer;
  } while(G4UniformRand()*crossSectionMaximum > DifferentialCrossSection(particleDefinition, 
									 k,
									 secElecKinetic+waterStructure.IonisationEnergy(shell),
									 shell));

  return(secElecKinetic);
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......


void G4DNARuddIonisationModel::RandomizeEjectedElectronDirection(G4ParticleDefinition* particleDefinition, 
								   G4double k, 
								   G4double secKinetic, 
								   G4double & cosTheta, 
								   G4double & phi )
{
  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  G4double maxSecKinetic = 0.;
 
  if (particleDefinition == G4Proton::ProtonDefinition() 
      || particleDefinition == instance->GetIon("hydrogen")) 
  { 
      maxSecKinetic = 4.* (electron_mass_c2 / proton_mass_c2) * k;
  }
  
  if (particleDefinition == instance->GetIon("helium") 
      || particleDefinition == instance->GetIon("alpha+")
      || particleDefinition == instance->GetIon("alpha++"))
  { 
      maxSecKinetic = 4.* (0.511 / 3728) * k;
  }
  
  phi = twopi * G4UniformRand();
  
  //cosTheta = std::sqrt(secKinetic / maxSecKinetic);

  // Restriction below 100 eV from Emfietzoglou (2000)

  if (secKinetic>100*eV) cosTheta = std::sqrt(secKinetic / maxSecKinetic);
  else cosTheta = (2.*G4UniformRand())-1.;
  
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......


G4double G4DNARuddIonisationModel::DifferentialCrossSection(G4ParticleDefinition* particleDefinition, 
							      G4double k, 
							      G4double energyTransfer, 
							      G4int ionizationLevelIndex)
{
  // Shells ids are 0 1 2 3 4 (4 is k shell)
  // !!Attention, "energyTransfer" here is the energy transfered to the electron which means
  //             that the secondary kinetic energy is w = energyTransfer - bindingEnergy
  //
  //   ds            S                F1(nu) + w * F2(nu)
  //  ---- = G(k) * ----     -------------------------------------------
  //   dw            Bj       (1+w)^3 * [1 + exp{alpha * (w - wc) / nu}]
  //
  // w is the secondary electron kinetic Energy in eV
  //
  // All the other parameters can be found in Rudd's Papers
  //
  // M.Eugene Rudd, 1988, User-Friendly model for the energy distribution of
  // electrons from protons or electron collisions. Nucl. Tracks Rad. Meas.Vol 16 N0 2/3 pp 219-218
  //

  const G4int j=ionizationLevelIndex;

  G4double A1 ; 
  G4double B1 ; 
  G4double C1 ; 
  G4double D1 ; 
  G4double E1 ;
  G4double A2 ; 
  G4double B2 ; 
  G4double C2 ; 
  G4double D2 ; 
  G4double alphaConst ;

//  const G4double Bj[5] = {12.61*eV, 14.73*eV, 18.55*eV, 32.20*eV, 539.7*eV};
// The following values are provided by M. dingfelder (priv. comm)
  const G4double Bj[5] = {12.60*eV, 14.70*eV, 18.40*eV, 32.20*eV, 540*eV};

  if (j == 4) 
  {
      //Data For Liquid Water K SHELL from Dingfelder (Protons in Water)
      A1 = 1.25; 
      B1 = 0.5; 
      C1 = 1.00; 
      D1 = 1.00; 
      E1 = 3.00; 
      A2 = 1.10; 
      B2 = 1.30;
      C2 = 1.00; 
      D2 = 0.00; 
      alphaConst = 0.66;
  }
  else 
  {
      //Data For Liquid Water from Dingfelder (Protons in Water)
      A1 = 1.02; 
      B1 = 82.0; 
      C1 = 0.45; 
      D1 = -0.80; 
      E1 = 0.38; 
      A2 = 1.07; 
      // Value provided by M. Dingfelder (priv. comm)
      B2 = 11.6;
      //
      C2 = 0.60; 
      D2 = 0.04; 
      alphaConst = 0.64;
  }
  
  const G4double n = 2.;
  const G4double Gj[5] = {0.99, 1.11, 1.11, 0.52, 1.};

  G4DNAGenericIonsManager* instance;
  instance = G4DNAGenericIonsManager::Instance();

  G4double wBig = (energyTransfer - waterStructure.IonisationEnergy(ionizationLevelIndex));
  if (wBig<0) return 0.;

  G4double w = wBig / Bj[ionizationLevelIndex];
  // Note that the following (j==4) cases are provided by   M. Dingfelder (priv. comm)
  if (j==4) w = wBig / waterStructure.IonisationEnergy(ionizationLevelIndex);

  G4double Ry = 13.6*eV;

  G4double tau = 0.;

  if (particleDefinition == G4Proton::ProtonDefinition() 
      || particleDefinition == instance->GetIon("hydrogen")) 
  {
      tau = (electron_mass_c2/proton_mass_c2) * k ;
  }
   
  if ( particleDefinition == instance->GetIon("helium") 
       || particleDefinition == instance->GetIon("alpha+")
       || particleDefinition == instance->GetIon("alpha++")) 
  {
      tau = (0.511/3728.) * k ;
  }

  G4double S = 4.*pi * Bohr_radius*Bohr_radius * n * std::pow((Ry/Bj[ionizationLevelIndex]),2);
  if (j==4) S = 4.*pi * Bohr_radius*Bohr_radius * n * std::pow((Ry/waterStructure.IonisationEnergy(ionizationLevelIndex)),2);

  G4double v2 = tau / Bj[ionizationLevelIndex];
  if (j==4) v2 = tau / waterStructure.IonisationEnergy(ionizationLevelIndex);

  G4double v = std::sqrt(v2);
  G4double wc = 4.*v2 - 2.*v - (Ry/(4.*Bj[ionizationLevelIndex]));
  if (j==4) wc = 4.*v2 - 2.*v - (Ry/(4.*waterStructure.IonisationEnergy(ionizationLevelIndex)));

  G4double L1 = (C1* std::pow(v,(D1))) / (1.+ E1*std::pow(v, (D1+4.)));
  G4double L2 = C2*std::pow(v,(D2));
  G4double H1 = (A1*std::log(1.+v2)) / (v2+(B1/v2));
  G4double H2 = (A2/v2) + (B2/(v2*v2));

  G4double F1 = L1+H1;
  G4double F2 = (L2*H2)/(L2+H2);

  G4double sigma = CorrectionFactor(particleDefinition, k) 
    * Gj[j] * (S/Bj[ionizationLevelIndex]) 
    * ( (F1+w*F2) / ( std::pow((1.+w),3) * ( 1.+std::exp(alphaConst*(w-wc)/v))) );

  if (j==4) sigma = CorrectionFactor(particleDefinition, k) 
    * Gj[j] * (S/waterStructure.IonisationEnergy(ionizationLevelIndex)) 
    * ( (F1+w*F2) / ( std::pow((1.+w),3) * ( 1.+std::exp(alphaConst*(w-wc)/v))) );

  if ( (particleDefinition == instance->GetIon("hydrogen")) && (ionizationLevelIndex==4)) 

//    sigma = Gj[j] * (S/Bj[ionizationLevelIndex]) 
    sigma = Gj[j] * (S/waterStructure.IonisationEnergy(ionizationLevelIndex)) 
    * ( (F1+w*F2) / ( std::pow((1.+w),3) * ( 1.+std::exp(alphaConst*(w-wc)/v))) );

  if (    particleDefinition == G4Proton::ProtonDefinition() 
	  || particleDefinition == instance->GetIon("hydrogen")
	  ) 
  {
      return(sigma);
  }

  if (particleDefinition == instance->GetIon("alpha++") ) 
  {
      slaterEffectiveCharge[0]=0.;
      slaterEffectiveCharge[1]=0.;
      slaterEffectiveCharge[2]=0.;
      sCoefficient[0]=0.;
      sCoefficient[1]=0.;
      sCoefficient[2]=0.;
  }

  if (particleDefinition == instance->GetIon("alpha+") ) 
  {
      slaterEffectiveCharge[0]=2.0;
      // The following values are provided by M. Dingfelder (priv. comm)    
      slaterEffectiveCharge[1]=2.0;
      slaterEffectiveCharge[2]=2.0;
      //
      sCoefficient[0]=0.7;
      sCoefficient[1]=0.15;
      sCoefficient[2]=0.15;
  }

  if (particleDefinition == instance->GetIon("helium") ) 
  {
      slaterEffectiveCharge[0]=1.7;
      slaterEffectiveCharge[1]=1.15;
      slaterEffectiveCharge[2]=1.15;
      sCoefficient[0]=0.5;
      sCoefficient[1]=0.25;
      sCoefficient[2]=0.25;
  }
  
  if (    particleDefinition == instance->GetIon("helium") 
	  || particleDefinition == instance->GetIon("alpha+")
	  || particleDefinition == instance->GetIon("alpha++")
	  ) 
  {
      sigma = Gj[j] * (S/Bj[ionizationLevelIndex]) * ( (F1+w*F2) / ( std::pow((1.+w),3) * ( 1.+std::exp(alphaConst*(w-wc)/v))) );
    
      if (j==4) sigma = Gj[j] * (S/waterStructure.IonisationEnergy(ionizationLevelIndex)) 
                              * ( (F1+w*F2) / ( std::pow((1.+w),3) * ( 1.+std::exp(alphaConst*(w-wc)/v))) );

      G4double zEff = particleDefinition->GetPDGCharge() / eplus + particleDefinition->GetLeptonNumber();
  
      zEff -= ( sCoefficient[0] * S_1s(k, energyTransfer, slaterEffectiveCharge[0], 1.) +
		sCoefficient[1] * S_2s(k, energyTransfer, slaterEffectiveCharge[1], 2.) +
		sCoefficient[2] * S_2p(k, energyTransfer, slaterEffectiveCharge[2], 2.) );
	   
      return zEff * zEff * sigma ;
  }  
  
  return 0;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::S_1s(G4double t, 
					  G4double energyTransferred, 
					  G4double slaterEffectiveChg, 
					  G4double shellNumber)
{
  // 1 - e^(-2r) * ( 1 + 2 r + 2 r^2)
  // Dingfelder, in Chattanooga 2005 proceedings, formula (7)
 
  G4double r = R(t, energyTransferred, slaterEffectiveChg, shellNumber);
  G4double value = 1. - std::exp(-2 * r) * ( ( 2. * r + 2. ) * r + 1. );
  
  return value;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::S_2s(G4double t,
					  G4double energyTransferred, 
					  G4double slaterEffectiveChg, 
					  G4double shellNumber)
{
  // 1 - e^(-2 r) * ( 1 + 2 r + 2 r^2 + 2 r^4)
  // Dingfelder, in Chattanooga 2005 proceedings, formula (8)

  G4double r = R(t, energyTransferred, slaterEffectiveChg, shellNumber);
  G4double value =  1. - std::exp(-2 * r) * (((2. * r * r + 2.) * r + 2.) * r + 1.);

  return value;
 
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::S_2p(G4double t, 
					  G4double energyTransferred,
					  G4double slaterEffectiveChg, 
					  G4double shellNumber)
{
  // 1 - e^(-2 r) * ( 1 + 2 r + 2 r^2 + 4/3 r^3 + 2/3 r^4)
  // Dingfelder, in Chattanooga 2005 proceedings, formula (9)

  G4double r = R(t, energyTransferred, slaterEffectiveChg, shellNumber);
  G4double value =  1. - std::exp(-2 * r) * (((( 2./3. * r + 4./3.) * r + 2.) * r + 2.) * r  + 1.);

  return value;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::R(G4double t,
				       G4double energyTransferred,
				       G4double slaterEffectiveChg,
				       G4double shellNumber) 
{
  // tElectron = m_electron / m_alpha * t
  // Dingfelder, in Chattanooga 2005 proceedings, p 4

  G4double tElectron = 0.511/3728. * t;
  // The following values are provided by M. Dingfelder (priv. comm)    
  G4double H = 2.*13.60569172 * eV;
  G4double value = std::sqrt ( 2. * tElectron / H ) / ( energyTransferred / H ) *  (slaterEffectiveChg/shellNumber);
  
  return value;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::CorrectionFactor(G4ParticleDefinition* particleDefinition, G4double k) 
{
  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  if (particleDefinition == G4Proton::Proton()) 
  {
      return(1.);
  }
  else 
    if (particleDefinition == instance->GetIon("hydrogen")) 
    { 
	G4double value = (std::log10(k/eV)-4.2)/0.5;
	// The following values are provided by M. Dingfelder (priv. comm)    
        return((0.6/(1+std::exp(value))) + 0.9);
    }
    else 
    {    
	return(1.);
    }
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4int G4DNARuddIonisationModel::RandomSelect(G4double k, const G4String& particle )
{   
  
  // BEGIN PART 1/2 OF ELECTRON CORRECTION

  // add ONE or TWO electron-water ionisation for alpha+ and helium
   
  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();
 
  G4int level = 0;

  // Retrieve data table corresponding to the current particle type  

  std::map< G4String,G4DNACrossSectionDataSet*,std::less<G4String> >::iterator pos;
  pos = tableData.find(particle);

  if (pos != tableData.end())
  {
      G4DNACrossSectionDataSet* table = pos->second;

      if (table != 0)
      {
	  G4double* valuesBuffer = new G4double[table->NumberOfComponents()];
	    
	  const size_t n(table->NumberOfComponents());
	  size_t i(n);
	  G4double value = 0.;
	    
	  while (i>0)
	  { 
	      i--;
	      valuesBuffer[i] = table->GetComponent(i)->FindValue(k);
	      value += valuesBuffer[i];
	  }
	    
	  value *= G4UniformRand();
	    
	  i = n;
	    
	  while (i > 0)
	  {
	      i--;
	      
		
	      if (valuesBuffer[i] > value)
	      {
		  delete[] valuesBuffer;
		  return i;
	      }
	      value -= valuesBuffer[i];
	  }
	    
	  if (valuesBuffer) delete[] valuesBuffer;
	    
      }
  }
  else
  {
    G4Exception("G4DNARuddIonisationModel::RandomSelect: attempting to calculate cross section for wrong particle");
  }

  return level;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::PartialCrossSection(const G4Track& track )
{
  G4double sigma = 0.;

  const G4DynamicParticle* particle = track.GetDynamicParticle();
  G4double k = particle->GetKineticEnergy();
  
  G4double lowLim = 0;
  G4double highLim = 0;

  const G4String& particleName = particle->GetDefinition()->GetParticleName();

  std::map< G4String,G4double,std::less<G4String> >::iterator pos1;
  pos1 = lowEnergyLimit.find(particleName);

  if (pos1 != lowEnergyLimit.end())
  {
    lowLim = pos1->second;
  }

  std::map< G4String,G4double,std::less<G4String> >::iterator pos2;
  pos2 = highEnergyLimit.find(particleName);

  if (pos2 != highEnergyLimit.end())
  {
    highLim = pos2->second;
  }

  if (k >= lowLim && k <= highLim)
  {
      std::map< G4String,G4DNACrossSectionDataSet*,std::less<G4String> >::iterator pos;
      pos = tableData.find(particleName);
	
      if (pos != tableData.end())
      {
	  G4DNACrossSectionDataSet* table = pos->second;
	  if (table != 0)
          {
	      sigma = table->FindValue(k);
          }
      }
      else
      {
	  G4Exception("G4DNARuddIonisationModel::PartialCrossSection: attempting to calculate cross section for wrong particle");
      }
  }

  return sigma;
}

//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......

G4double G4DNARuddIonisationModel::Sum(G4double /* energy */, const G4String& /* particle */)
{
  return 0;
}

