G4IonisParamMat.cc

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// $Id$
//
// 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
// 09-07-98, data moved from G4Material, M.Maire
// 18-07-98, bug corrected in ComputeDensityEffect() for gas
// 16-01-01, bug corrected in ComputeDensityEffect() E100eV (L.Urban)
// 08-02-01, fShellCorrectionVector correctly handled (mma)
// 28-10-02, add setMeanExcitationEnergy (V.Ivanchenko)
// 06-09-04, factor 2 to shell correction term (V.Ivanchenko) 
// 10-05-05, add a missing coma in FindMeanExcitationEnergy() - Bug#746 (mma)
// 27-09-07, add computation of parameters for ions (V.Ivanchenko)
// 04-03-08, remove reference to G4NistManager. Add fBirks constant (mma)
// 30-10-09, add G4DensityEffectData class and density effect computation (VI)
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
#include "G4IonisParamMat.hh"
#include "G4Material.hh"
#include "G4DensityEffectData.hh"
#include "G4NistManager.hh"
#include "G4Pow.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
 
G4DensityEffectData* G4IonisParamMat::fDensityData = 0;
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4IonisParamMat::G4IonisParamMat(G4Material* material)
  : fMaterial(material)
{
  fBirks = 0.;
  fMeanEnergyPerIon = 0.0;
  twoln10 = 2.*G4Pow::GetInstance()->logZ(10);
 
  // minimal set of default parameters for density effect
  fCdensity = 0.0;
  fD0density = 0.0;
  fAdjustmentFactor = 1.0;
  if(!fDensityData) { fDensityData = new G4DensityEffectData(); }
 
  // compute parameters
  ComputeMeanParameters();
  ComputeDensityEffect();
  ComputeFluctModel();
  ComputeIonParameters();
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
// Fake default constructor - sets only member data and allocates memory
//                            for usage restricted to object persistency
 
G4IonisParamMat::G4IonisParamMat(__void__&)
  : fMaterial(0), fShellCorrectionVector(0)
{
  fMeanExcitationEnergy = 0.0;
  fLogMeanExcEnergy = 0.0;
  fTaul = 0.0;
  fCdensity = 0.0;
  fMdensity = 0.0;
  fAdensity = 0.0;
  fX0density = 0.0;
  fX1density = 0.0;
  fD0density = 0.0;
  fPlasmaEnergy = 0.0;
  fAdjustmentFactor = 0.0;
  fF1fluct = 0.0;          
  fF2fluct = 0.0;                       
  fEnergy1fluct = 0.0;
  fLogEnergy1fluct = 0.0;
  fEnergy2fluct = 0.0;
  fLogEnergy2fluct = 0.0;
  fEnergy0fluct = 0.0;
  fRateionexcfluct = 0.0;
  fZeff = 0.0;
  fFermiEnergy = 0.0;
  fLfactor = 0.0;
  fInvA23 = 0.0;
  fBirks = 0.0;
  fMeanEnergyPerIon = 0.0;
  twoln10 = 2.*G4Pow::GetInstance()->logZ(10);
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4IonisParamMat::~G4IonisParamMat()
{
  if (fShellCorrectionVector) { delete [] fShellCorrectionVector; }
  if (fDensityData) { delete fDensityData; }
  fDensityData = 0;
  fShellCorrectionVector = 0;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
void G4IonisParamMat::ComputeMeanParameters()
{
  // compute mean excitation energy and shell correction vector
  fTaul = (*(fMaterial->GetElementVector()))[0]->GetIonisation()->GetTaul();
 
  fMeanExcitationEnergy = 0.;
  fLogMeanExcEnergy = 0.;
 
  size_t nElements = fMaterial->GetNumberOfElements();
  const G4ElementVector* elmVector = fMaterial->GetElementVector();
  const G4double* nAtomsPerVolume = fMaterial->GetVecNbOfAtomsPerVolume();
 
  const G4String ch = fMaterial->GetChemicalFormula();
 
  if(ch != "") { fMeanExcitationEnergy = FindMeanExcitationEnergy(ch); }
 
  // Chemical formula defines mean excitation energy
  if(fMeanExcitationEnergy > 0.0) {
    fLogMeanExcEnergy = std::log(fMeanExcitationEnergy);
 
    // Compute average 
  } else {
    for (size_t i=0; i < nElements; i++) {
      const G4Element* elm = (*elmVector)[i];
      fLogMeanExcEnergy += nAtomsPerVolume[i]*elm->GetZ()
    *std::log(elm->GetIonisation()->GetMeanExcitationEnergy());
    }
    fLogMeanExcEnergy /= fMaterial->GetTotNbOfElectPerVolume();
    fMeanExcitationEnergy = std::exp(fLogMeanExcEnergy);
  }
 
  fShellCorrectionVector = new G4double[3]; 
 
  for (G4int j=0; j<=2; j++)
  {
    fShellCorrectionVector[j] = 0.;
 
    for (size_t k=0; k<nElements; k++) {
      fShellCorrectionVector[j] += nAtomsPerVolume[k]
    *(((*elmVector)[k])->GetIonisation()->GetShellCorrectionVector())[j];
    }
    fShellCorrectionVector[j] *= 2.0/fMaterial->GetTotNbOfElectPerVolume();
  } 
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4DensityEffectData* G4IonisParamMat::GetDensityEffectData()
{
  return fDensityData;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
                    
void G4IonisParamMat::ComputeDensityEffect()
{
  G4State State = fMaterial->GetState();
 
  // Check if density effect data exist in the table
  // R.M. Sternheimer, Atomic Data and Nuclear Data Tables, 30: 261 (1984)
  G4int idx = fDensityData->GetIndex(fMaterial->GetName());
  G4int nelm= fMaterial->GetNumberOfElements();
  G4int Z0  = G4int((*(fMaterial->GetElementVector()))[0]->GetZ()+0.5);
  if(idx < 0 && 1 == nelm) {
    idx = fDensityData->GetElementIndex(Z0, fMaterial->GetState());
  }
 
  //G4cout<<"DensityEffect for "<<fMaterial->GetName()<<"  "<< idx << G4endl; 
 
  if(idx >= 0) {
 
    // Take parameters for the density effect correction from
    // R.M. Sternheimer et al. Density Effect For The Ionization Loss 
    // of Charged Particles in Various Substances. 
    // Atom. Data Nucl. Data Tabl. 30 (1984) 261-271. 
 
    fCdensity = fDensityData->GetCdensity(idx); 
    fMdensity = fDensityData->GetMdensity(idx);
    fAdensity = fDensityData->GetAdensity(idx);
    fX0density = fDensityData->GetX0density(idx);
    fX1density = fDensityData->GetX1density(idx);
    fD0density = fDensityData->GetDelta0density(idx);
    fPlasmaEnergy = fDensityData->GetPlasmaEnergy(idx);
    fAdjustmentFactor = fDensityData->GetAdjustmentFactor(idx);
 
    // Correction for base material
    const G4Material* bmat = fMaterial->GetBaseMaterial();
    if(bmat) {
      G4double corr = std::log(bmat->GetDensity()/fMaterial->GetDensity());
      fCdensity  += corr;
      fX0density += corr/twoln10;
      fX1density += corr/twoln10;
    }
 
  } else {
 
    const G4double Cd2 = 4*pi*hbarc_squared*classic_electr_radius;
    fPlasmaEnergy = std::sqrt(Cd2*fMaterial->GetTotNbOfElectPerVolume());
 
    // Compute parameters for the density effect correction in DE/Dx formula.
    // The parametrization is from R.M. Sternheimer, Phys. Rev.B,3:3681 (1971)
    G4int icase;
    
    fCdensity = 1. + 2*std::log(fMeanExcitationEnergy/fPlasmaEnergy);
    //
    // condensed materials
    //  
    if ((State == kStateSolid)||(State == kStateLiquid)) {
 
      const G4double E100eV  = 100.*eV; 
      const G4double ClimiS[] = {3.681 , 5.215 };
      const G4double X0valS[] = {1.0   , 1.5   };
      const G4double X1valS[] = {2.0   , 3.0   };
                                
      if(fMeanExcitationEnergy < E100eV) { icase = 0; }
      else                               { icase = 1; } 
 
      if(fCdensity < ClimiS[icase])    { fX0density = 0.2; }
      else { fX0density = 0.326*fCdensity - X0valS[icase]; }
 
      fX1density = X1valS[icase]; fMdensity = 3.0;
      
      //special: Hydrogen
      if (1 == nelm && 1 == Z0) {
         fX0density = 0.425; fX1density = 2.0; fMdensity = 5.949;
      }
    }
    //
    // gases
    //
    if (State == kStateGas) { 
 
      const G4double ClimiG[] = { 10. , 10.5 , 11. , 11.5 , 12.25 , 13.804};
      const G4double X0valG[] = { 1.6 , 1.7 ,  1.8 ,  1.9 , 2.0   ,  2.0 };
      const G4double X1valG[] = { 4.0 , 4.0 ,  4.0 ,  4.0 , 4.0   ,  5.0 };
 
      icase = 5;
      fX0density = 0.326*fCdensity-2.5 ; fX1density = 5.0 ; fMdensity = 3. ; 
      while((icase > 0)&&(fCdensity < ClimiG[icase])) { icase-- ; }
      fX0density = X0valG[icase]; fX1density = X1valG[icase];
      
      //special: Hydrogen
      if (1 == nelm && 1 == Z0) {
         fX0density = 1.837; fX1density = 3.0; fMdensity = 4.754;
      }
      
      //special: Helium
      if (1 == nelm && 2 == Z0) {
         fX0density = 2.191; fX1density = 3.0; fMdensity = 3.297;
      }
    }
  }
 
  // change parameters if the gas is not in STP.
  // For the correction the density(STP) is needed. 
  // Density(STP) is calculated here : 
  
    
  if (State == kStateGas) { 
    G4double Density  = fMaterial->GetDensity();
    G4double Pressure = fMaterial->GetPressure();
    G4double Temp     = fMaterial->GetTemperature();
      
    G4double DensitySTP = Density*STP_Pressure*Temp/(Pressure*STP_Temperature);
 
    G4double ParCorr = std::log(Density/DensitySTP);
  
    fCdensity  -= ParCorr;
    fX0density -= ParCorr/twoln10;
    fX1density -= ParCorr/twoln10;
  }
 
  // fAdensity parameter can be fixed for not conductive materials 
  if(0.0 == fD0density) {
    G4double Xa = fCdensity/twoln10;
    fAdensity = twoln10*(Xa-fX0density)
      /std::pow((fX1density-fX0density),fMdensity);
  }
  /*  
  G4cout << "G4IonisParamMat: density effect data for <" << fMaterial->GetName() 
     << "> " << G4endl;
  G4cout << "Eplasma(eV)= " << fPlasmaEnergy/eV
     << " rho= " << fAdjustmentFactor
     << " -C= " << fCdensity 
     << " x0= " << fX0density
     << " x1= " << fX1density
     << " a= " << fAdensity
     << " m= " << fMdensity
     << G4endl;
  */
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
void G4IonisParamMat::ComputeFluctModel()
{
  // compute parameters for the energy loss fluctuation model
  // needs an 'effective Z' 
  G4double Zeff = 0.;
  for (size_t i=0;i<fMaterial->GetNumberOfElements();i++) {
     Zeff += (fMaterial->GetFractionVector())[i]
             *((*(fMaterial->GetElementVector()))[i]->GetZ());
  }
  if (Zeff > 2.) { fF2fluct = 2./Zeff; }
  else           { fF2fluct = 0.; }
 
  fF1fluct         = 1. - fF2fluct;
  fEnergy2fluct    = 10.*Zeff*Zeff*eV;
  fLogEnergy2fluct = std::log(fEnergy2fluct);
  fLogEnergy1fluct = (fLogMeanExcEnergy - fF2fluct*fLogEnergy2fluct)
                     /fF1fluct;
  fEnergy1fluct    = std::exp(fLogEnergy1fluct);
  fEnergy0fluct    = 10.*eV;
  fRateionexcfluct = 0.4;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
void G4IonisParamMat::ComputeIonParameters()
{
  // get elements in the actual material,
  const G4ElementVector* theElementVector = fMaterial->GetElementVector() ;
  const G4double* theAtomicNumDensityVector =
                         fMaterial->GetAtomicNumDensityVector() ;
  const G4int NumberOfElements = fMaterial->GetNumberOfElements() ;
 
  //  loop for the elements in the material
  //  to find out average values Z, vF, lF
  G4double z(0.0), vF(0.0), lF(0.0), norm(0.0), a23(0.0);
 
  if( 1 == NumberOfElements ) {
    const G4Element* element = (*theElementVector)[0];
    z = element->GetZ();
    vF= element->GetIonisation()->GetFermiVelocity();
    lF= element->GetIonisation()->GetLFactor();
    a23 = 1.0/G4Pow::GetInstance()->Z23(G4int(element->GetN()));
 
  } else {
    for (G4int iel=0; iel<NumberOfElements; iel++)
      {
        const G4Element* element = (*theElementVector)[iel];
        const G4double weight = theAtomicNumDensityVector[iel];
        norm += weight ;
        z    += element->GetZ() * weight;
        vF   += element->GetIonisation()->GetFermiVelocity() * weight;
        lF   += element->GetIonisation()->GetLFactor() * weight;
    a23  += weight/G4Pow::GetInstance()->Z23(G4int(element->GetN()));
      }
    z  /= norm;
    vF /= norm;
    lF /= norm;
    a23 /= norm;
  }  
  fZeff        = z;
  fLfactor     = lF;
  fFermiEnergy = 25.*keV*vF*vF;
  fInvA23      = a23;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
void G4IonisParamMat::SetMeanExcitationEnergy(G4double value)
{
  if(value == fMeanExcitationEnergy || value <= 0.0) { return; }
  if (G4NistManager::Instance()->GetVerbose() > 1) {
    G4cout << "G4Material: Mean excitation energy is changed for "
           << fMaterial->GetName()
           << " Iold= " << fMeanExcitationEnergy/eV
           << "eV; Inew= " << value/eV << " eV;"
           << G4endl;
  }
  
  fMeanExcitationEnergy = value;
 
  // add corrections to density effect
  G4double newlog = std::log(value);
  G4double corr = 2*(newlog - fLogMeanExcEnergy);
  fCdensity  += corr;
  fX0density += corr/twoln10;
  fX1density += corr/twoln10;
 
  // recompute parameters of fluctuation model
  fLogMeanExcEnergy = newlog;
  ComputeFluctModel();
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4double G4IonisParamMat::FindMeanExcitationEnergy(const G4String& chFormula)
{
  // The data on mean excitation energy for compaunds
  // from "Stopping Powers for Electrons and Positrons"
  // ICRU Report N#37, 1984  (energy in eV)
 
  const size_t numberOfMolecula = 54; 
  static G4String name[numberOfMolecula] = {
    // gas 0 - 12
    "NH_3",       "C_4H_10",    "CO_2",       "C_2H_6",      "C_7H_16",
    "C_6H_14",    "CH_4",       "NO",         "N_2O",        "C_8H_18",
    "C_5H_12",    "C_3H_8",     "H_2O-Gas", 
 
    // liquid 13 - 39
    "C_3H_6O",    "C_6H_5NH_2",  "C_6H_6",    "C_4H_9OH",    "CCl_4",    
    "C_6H_5Cl",   "CHCl_3",      "C_6H_12",   "C_6H_4Cl_2",  "C_4Cl_2H_8O", 
    "C_2Cl_2H_4", "(C_2H_5)_2O", "C_2H_5OH",  "C_3H_5(OH)_3","C_7H_16",     
    "C_6H_14",    "CH_3OH",      "C_6H_5NO_2","C_5H_12",     "C_3H_7OH",    
    "C_5H_5N",    "C_8H_8",      "C_2Cl_4",   "C_7H_8",      "C_2Cl_3H",    
    "H_2O",       "C_8H_10",
 
    // solid 40 - 53
    "C_5H_5N_5",  "C_5H_5N_5O",  "(C_6H_11NO)-nylon",  "C_25H_52", 
    "(C_2H_4)-Polyethylene",     "(C_5H_8O-2)-Polymethil_Methacrylate",   
    "(C_8H_8)-Polystyrene",      "A-150-tissue",       "Al_2O_3",  "CaF_2", 
    "LiF",        "Photo_Emulsion",  "(C_2F_4)-Teflon",  "SiO_2"     
  };
    
  static G4double meanExcitation[numberOfMolecula] = {
 
    53.7,   48.3,  85.0,  45.4,  49.2,
    49.1,   41.7,  87.8,  84.9,  49.5,
    48.2,   47.1,  71.6,
 
    64.2,   66.2,  63.4,  59.9,  166.3,
    89.1,  156.0,  56.4, 106.5,  103.3, 
   111.9,   60.0,  62.9,  72.6,   54.4,  
    54.0,  67.6,   75.8,  53.6,   61.1,  
    66.2,  64.0,  159.2,  62.5,  148.1,  
    75.0,  61.8,
 
    71.4,  75.0,   63.9,  48.3,   57.4,
    74.0,  68.7,   65.1, 145.2,  166.,
    94.0, 331.0,   99.1, 139.2 
  };
 
  G4double x = fMeanExcitationEnergy;
 
  for(size_t i=0; i<numberOfMolecula; i++) {
    if(chFormula == name[i]) {
      x = meanExcitation[i]*eV;
      break;
    }
  }
  return x;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4IonisParamMat::G4IonisParamMat(const G4IonisParamMat& right)
{
  fShellCorrectionVector = 0;
  fMaterial = 0;
  *this = right;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4IonisParamMat& G4IonisParamMat::operator=(const G4IonisParamMat& right)
{
  if (this != &right)
    {
      fMaterial                 = right.fMaterial;
      fMeanExcitationEnergy     = right.fMeanExcitationEnergy;
      fLogMeanExcEnergy         = right.fLogMeanExcEnergy;
      if(fShellCorrectionVector){ delete [] fShellCorrectionVector; }      
      fShellCorrectionVector    = new G4double[3];             
      fShellCorrectionVector[0] = right.fShellCorrectionVector[0];
      fShellCorrectionVector[1] = right.fShellCorrectionVector[1];
      fShellCorrectionVector[2] = right.fShellCorrectionVector[2];
      fTaul                     = right.fTaul;
      fCdensity                 = right.fCdensity;
      fMdensity                 = right.fMdensity;
      fAdensity                 = right.fAdensity;
      fX0density                = right.fX0density;
      fX1density                = right.fX1density;
      fD0density                = right.fD0density;
      fPlasmaEnergy             = right.fPlasmaEnergy;
      fAdjustmentFactor         = right.fAdjustmentFactor;
      fF1fluct                  = right.fF1fluct;
      fF2fluct                  = right.fF2fluct;
      fEnergy1fluct             = right.fEnergy1fluct;
      fLogEnergy1fluct          = right.fLogEnergy1fluct;      
      fEnergy2fluct             = right.fEnergy2fluct;
      fLogEnergy2fluct          = right.fLogEnergy2fluct;      
      fEnergy0fluct             = right.fEnergy0fluct;
      fRateionexcfluct          = right.fRateionexcfluct;
      fZeff                     = right.fZeff;
      fFermiEnergy              = right.fFermiEnergy;
      fLfactor                  = right.fLfactor;
      fInvA23                   = right.fInvA23;
      fBirks                    = right.fBirks;
      fMeanEnergyPerIon         = right.fMeanEnergyPerIon;
      fDensityData              = right.fDensityData;
      twoln10                   = right.twoln10;
    } 
  return *this;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4int G4IonisParamMat::operator==(const G4IonisParamMat& right) const
{
  return (this == (G4IonisParamMat*) &right);
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....
 
G4int G4IonisParamMat::operator!=(const G4IonisParamMat& right) const
{
  return (this != (G4IonisParamMat*) &right);
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... ....oooOO0OOooo....