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// $Id: G4DNAMillerGreenExcitationModel.cc,v 1.3 2009/02/16 11:00:11 sincerti Exp $
// GEANT4 tag $Name: geant4-09-02-ref-02 $
//

#include "G4DNAMillerGreenExcitationModel.hh"

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using namespace std;

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G4DNAMillerGreenExcitationModel::G4DNAMillerGreenExcitationModel(const G4ParticleDefinition*,
                                             const G4String& nam)
:G4VEmModel(nam),isInitialised(false)
{

  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
  
  G4cout << "Miller & Green excitation model is constructed " << G4endl;

}

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G4DNAMillerGreenExcitationModel::~G4DNAMillerGreenExcitationModel()
{}

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void G4DNAMillerGreenExcitationModel::Initialise(const G4ParticleDefinition* particle,
                                       const G4DataVector& /*cuts*/)
{

  if (verboseLevel > 3)
    G4cout << "Calling G4DNAMillerGreenExcitationModel::Initialise()" << G4endl;

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

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

  if (protonDef != 0)
  {
    proton = protonDef->GetParticleName();
    lowEnergyLimit[proton] = 10. * eV;
    highEnergyLimit[proton] = 500. * keV;
    
    kineticEnergyCorrection[0] = 1.;
    slaterEffectiveCharge[0][0] = 0.;
    slaterEffectiveCharge[1][0] = 0.;
    slaterEffectiveCharge[2][0] = 0.;
    sCoefficient[0][0] = 0.;
    sCoefficient[1][0] = 0.;
    sCoefficient[2][0] = 0.;
  }
  else
  {
    G4Exception("G4DNAMillerGreenExcitationModel::Initialise: proton is not defined");
  }

  if (alphaPlusPlusDef != 0)
  {
    alphaPlusPlus = alphaPlusPlusDef->GetParticleName();
    lowEnergyLimit[alphaPlusPlus] = 1. * keV;
    highEnergyLimit[alphaPlusPlus] = 10. * MeV;

    kineticEnergyCorrection[1] = 0.9382723/3.727417;
    slaterEffectiveCharge[0][1]=0.;
    slaterEffectiveCharge[1][1]=0.;
    slaterEffectiveCharge[2][1]=0.;
    sCoefficient[0][1]=0.;
    sCoefficient[1][1]=0.;
    sCoefficient[2][1]=0.;
  }
  else
  {
      G4Exception("G4DNAMillerGreenExcitationModel::Initialise: alphaPlusPlus is not defined");
  }

  if (alphaPlusDef != 0)
  {
    alphaPlus = alphaPlusDef->GetParticleName();
    lowEnergyLimit[alphaPlus] = 1. * keV;
    highEnergyLimit[alphaPlus] = 10. * MeV;

    kineticEnergyCorrection[2] = 0.9382723/3.727417;
    slaterEffectiveCharge[0][2]=2.0;
    slaterEffectiveCharge[1][2]=1.15;
    slaterEffectiveCharge[2][2]=1.15;
    sCoefficient[0][2]=0.7;
    sCoefficient[1][2]=0.15;
    sCoefficient[2][2]=0.15;
  }
  else
  {
    G4Exception("G4DNAMillerGreenExcitationModel::Initialise: alphaPlus is not defined");
  }

  if (heliumDef != 0)
  {
    helium = heliumDef->GetParticleName();
    lowEnergyLimit[helium] = 1. * keV;
    highEnergyLimit[helium] = 10. * MeV;
    
    kineticEnergyCorrection[3] = 0.9382723/3.727417;
    slaterEffectiveCharge[0][3]=1.7;
    slaterEffectiveCharge[1][3]=1.15;
    slaterEffectiveCharge[2][3]=1.15;
    sCoefficient[0][3]=0.5;
    sCoefficient[1][3]=0.25;
    sCoefficient[2][3]=0.25;
  }
  else
  {
    G4Exception("G4DNAMillerGreenExcitationModel::Initialise: helium is not defined");
  }

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

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

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

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

  //
  
  nLevels = waterExcitation.NumberOfLevels();

  //
  
  G4cout << "Miller & Green excitation 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);
  
  // Test if water material

  flagMaterialIsWater= false;
  densityWater = 0;

  const G4ProductionCutsTable* theCoupleTable = G4ProductionCutsTable::GetProductionCutsTable();

  if(theCoupleTable) 
  {
    G4int numOfCouples = theCoupleTable->GetTableSize();
  
    if(numOfCouples>0) 
    {
	  for (G4int i=0; i<numOfCouples; i++) 
	  {
	    const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(i);
	    const G4Material* material = couple->GetMaterial();

            size_t j = material->GetNumberOfElements();
            while (j>0)
            {
               j--;
               const G4Element* element(material->GetElement(j));
               if (element->GetZ() == 8.)
	       {
	          G4double density = material->GetAtomicNumDensityVector()[j];
                  if (density > 0.) 
		  { 
		    flagMaterialIsWater = true; 
		    densityWater = density; 
		    
		    if (verboseLevel > 3) 
                    G4cout << "Water material is found with density(cm^-3)=" << density/(cm*cm*cm) << G4endl;
		  }
	       }
            }
  
          }
   } // if(numOfCouples>0)

  } // if (theCoupleTable)

}

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

G4double G4DNAMillerGreenExcitationModel::CrossSectionPerVolume(const G4Material* material,
					   const G4ParticleDefinition* particleDefinition,
					   G4double k,
					   G4double,
					   G4double)
{
  if (verboseLevel > 3)
    G4cout << "Calling CrossSectionPerVolume() of G4DNAMillerGreenExcitationModel" << G4endl;

 // Calculate total cross section for model

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

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

  G4double lowLim = 0;
  G4double highLim = 0;
  G4double crossSection = 0.;

  if (flagMaterialIsWater)
  {
    const G4String& particleName = particleDefinition->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)
    {
      crossSection = Sum(k,particleDefinition);

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

      // add ONE or TWO electron-water excitation for alpha+ and helium
  
      if ( particleDefinition == instance->GetIon("alpha+") 
           ||
           particleDefinition == instance->GetIon("helium")
         ) 
      {
	  G4DNAEmfietzoglouExcitationModel * excitationXS = new G4DNAEmfietzoglouExcitationModel();

	  G4double sigmaExcitation=0;
	  G4double tmp =0.;
	  
	  if (k*0.511/3728 > 7.4*eV && k*0.511/3728 < 10*keV) sigmaExcitation = 
	    excitationXS->CrossSectionPerVolume(material,particleDefinition,k*0.511/3728,tmp,tmp)/densityWater;
       
	  if ( particleDefinition == instance->GetIon("alpha+") ) 
	    crossSection = crossSection +  sigmaExcitation ;
	  
	  if ( particleDefinition == instance->GetIon("helium") ) 
	    crossSection = crossSection + 2*sigmaExcitation ;
	  
	  delete excitationXS;
      }      

    }

    if (verboseLevel > 3)
    {
      G4cout << "---> Kinetic energy(eV)=" << k/eV << G4endl;
      G4cout << " - Cross section per water molecule (cm^2)=" << crossSection/cm/cm << G4endl;
      G4cout << " - Cross section per water molecule (cm^-1)=" << crossSection*densityWater/(1./cm) << G4endl;
    } 

  } // if (flagMaterialIsWater)

 return crossSection*densityWater;		   

}

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

void G4DNAMillerGreenExcitationModel::SampleSecondaries(std::vector<G4DynamicParticle*>* /*fvect*/,
					      const G4MaterialCutsCouple* /*couple*/,
					      const G4DynamicParticle* aDynamicParticle,
					      G4double,
					      G4double)
{

  if (verboseLevel > 3)
    G4cout << "Calling SampleSecondaries() of G4DNAMillerGreenExcitationModel" << G4endl;

  G4double particleEnergy0 = aDynamicParticle->GetKineticEnergy();
  
  G4int level = RandomSelect(particleEnergy0,aDynamicParticle->GetDefinition());

  G4double excitationEnergy = waterExcitation.ExcitationEnergy(level);
  G4double newEnergy = particleEnergy0 - excitationEnergy;
  
  if (newEnergy>0)
  {
      fParticleChangeForGamma->ProposeMomentumDirection(aDynamicParticle->GetMomentumDirection());
      fParticleChangeForGamma->SetProposedKineticEnergy(newEnergy);
      fParticleChangeForGamma->ProposeLocalEnergyDeposit(excitationEnergy);
  }

}

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

G4double G4DNAMillerGreenExcitationModel::PartialCrossSection(G4double k, G4int excitationLevel, 
								  const G4ParticleDefinition* particleDefinition)
{
  //                               ( ( z * aj ) ^ omegaj ) * ( t - ej ) ^ nu
  // sigma(t) = zEff^2 * sigma0 * --------------------------------------------
  //                               jj ^ ( omegaj + nu ) + t ^ ( omegaj + nu )
  //
  // where t is the kinetic energy corrected by Helium mass over proton mass for Helium ions
  //
  // zEff is:
  //  1 for protons
  //  2 for alpha++
  //  and  2 - c1 S_1s - c2 S_2s - c3 S_2p for alpha+ and He
  //
  // Dingfelder et al., RPC 59, 255-275, 2000 from Miller and Green (1973)
  // Formula (34) and Table 2
  
  const G4double sigma0(1.E+8 * barn);
  const G4double nu(1.);
  const G4double aj[]={876.*eV, 2084.* eV, 1373.*eV, 692.*eV, 900.*eV};
  const G4double jj[]={19820.*eV, 23490.*eV, 27770.*eV, 30830.*eV, 33080.*eV};
  const G4double omegaj[]={0.85, 0.88, 0.88, 0.78, 0.78};
  
  G4int particleTypeIndex = 0;
  G4DNAGenericIonsManager* instance;
  instance = G4DNAGenericIonsManager::Instance();

  if (particleDefinition == G4Proton::ProtonDefinition()) particleTypeIndex=0;
  if (particleDefinition == instance->GetIon("alpha++")) particleTypeIndex=1;
  if (particleDefinition == instance->GetIon("alpha+")) particleTypeIndex=2;
  if (particleDefinition == instance->GetIon("helium")) particleTypeIndex=3;
 
  G4double tCorrected;
  tCorrected = k * kineticEnergyCorrection[particleTypeIndex];

  // SI - added protection 
  if (tCorrected < waterExcitation.ExcitationEnergy(excitationLevel)) return 0;
  //
  
  G4int z = 10;

  G4double numerator;
  numerator = std::pow(z * aj[excitationLevel], omegaj[excitationLevel]) * 
    std::pow(tCorrected - waterExcitation.ExcitationEnergy(excitationLevel), nu);

  G4double power;
  power = omegaj[excitationLevel] + nu;

  G4double denominator;
  denominator = std::pow(jj[excitationLevel], power) + std::pow(tCorrected, power);

  G4double zEff = particleDefinition->GetPDGCharge() / eplus + particleDefinition->GetLeptonNumber();

  zEff -= ( sCoefficient[0][particleTypeIndex] * S_1s(k, waterExcitation.ExcitationEnergy(excitationLevel), slaterEffectiveCharge[0][particleTypeIndex], 1.) +
	    sCoefficient[1][particleTypeIndex] * S_2s(k, waterExcitation.ExcitationEnergy(excitationLevel), slaterEffectiveCharge[1][particleTypeIndex], 2.) +
	    sCoefficient[2][particleTypeIndex] * S_2p(k, waterExcitation.ExcitationEnergy(excitationLevel), slaterEffectiveCharge[2][particleTypeIndex], 2.) );

  G4double cross = sigma0 * zEff * zEff * numerator / denominator;

  return cross;
}

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

G4int G4DNAMillerGreenExcitationModel::RandomSelect(G4double k,const G4ParticleDefinition* particle)
{
  G4int i = nLevels;
  G4double value = 0.;
  std::deque<double> values;
  
  G4DNAGenericIonsManager *instance;
  instance = G4DNAGenericIonsManager::Instance();

  if ( particle == instance->GetIon("alpha++") ||
       particle == G4Proton::ProtonDefinition()  )
  {  
     while (i > 0)
     {
	i--;
	G4double partial = PartialCrossSection(k,i,particle);
	values.push_front(partial);
	value += partial;
     }

     value *= G4UniformRand();
    
     i = nLevels;

     while (i > 0)
     {
	i--;
	if (values[i] > value) return i;
	value -= values[i];
     }
  } 

  // add ONE or TWO electron-water excitation for alpha+ and helium
   
  if ( particle == instance->GetIon("alpha+") 
       ||
       particle == instance->GetIon("helium")
     ) 
  {
    while (i>0)
    {
	  i--;
         
          G4DNAEmfietzoglouExcitationModel * excitationXS = new G4DNAEmfietzoglouExcitationModel();
         
	  G4double sigmaExcitation=0;

	  if (k*0.511/3728 > 7.4*eV && k*0.511/3728 < 10*keV) sigmaExcitation = excitationXS->PartialCrossSection(k*0.511/3728,i);
 
	  G4double partial = PartialCrossSection(k,i,particle);
	  if (particle == instance->GetIon("alpha+")) partial = PartialCrossSection(k,i,particle) + sigmaExcitation;
	  if (particle == instance->GetIon("helium")) partial = PartialCrossSection(k,i,particle) + 2*sigmaExcitation;
	  values.push_front(partial);
	  value += partial;
	  delete excitationXS;
    }
  
    value*=G4UniformRand();
  
    i=5;
    while (i>0)
    {
	  i--;
   
	  if (values[i]>value) return i;
  
	  value-=values[i];
    }
  }    	

  return 0;
}

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

G4double G4DNAMillerGreenExcitationModel::Sum(G4double k, const G4ParticleDefinition* particle)
{
  G4double totalCrossSection = 0.;

  for (G4int i=0; i<nLevels; i++)
  {
    totalCrossSection += PartialCrossSection(k,i,particle);
  }
  return totalCrossSection;
}

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

G4double G4DNAMillerGreenExcitationModel::S_1s(G4double t,
							  G4double energyTransferred,
							  G4double slaterEffectiveCharge,
							  G4double shellNumber)
{
  // 1 - e^(-2r) * ( 1 + 2 r + 2 r^2)
  // Dingfelder, in Chattanooga 2005 proceedings, formula (7)
 
  G4double r = R(t, energyTransferred, slaterEffectiveCharge, shellNumber);
  G4double value = 1. - std::exp(-2 * r) * ( ( 2. * r + 2. ) * r + 1. );
  
  return value;
}


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

G4double G4DNAMillerGreenExcitationModel::S_2s(G4double t,
							  G4double energyTransferred,
							  G4double slaterEffectiveCharge,
							  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, slaterEffectiveCharge, shellNumber);
  G4double value =  1. - std::exp(-2 * r) * (((2. * r * r + 2.) * r + 2.) * r + 1.);

  return value;
 
}

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

G4double G4DNAMillerGreenExcitationModel::S_2p(G4double t,
							  G4double energyTransferred,
							  G4double slaterEffectiveCharge,
							  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, slaterEffectiveCharge, 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 G4DNAMillerGreenExcitationModel::R(G4double t,
						       G4double energyTransferred,
						       G4double slaterEffectiveCharge,
						       G4double shellNumber) 
{
  // tElectron = m_electron / m_alpha * t
  // Dingfelder, in Chattanooga 2005 proceedings, p 4

  G4double tElectron = 0.511/3728. * t;
  G4double value = 2. * tElectron * slaterEffectiveCharge / (energyTransferred * shellNumber);
  
  return value;
}