G4VCrossSectionHandler Class Reference

#include <G4VCrossSectionHandler.hh>

Inheritance diagram for G4VCrossSectionHandler:

Public Member Functions
	G4VCrossSectionHandler ()
	G4VCrossSectionHandler (G4VDataSetAlgorithm *interpolation, G4double minE=250 *CLHEP::eV, G4double maxE=100 *CLHEP::GeV, G4int nBins=200, G4double unitE=CLHEP::MeV, G4double unitData=CLHEP::barn, G4int minZ=1, G4int maxZ=99)
virtual	~G4VCrossSectionHandler ()
void	Initialise (G4VDataSetAlgorithm *interpolation=0, G4double minE=250 *CLHEP::eV, G4double maxE=100 *CLHEP::GeV, G4int numberOfBins=200, G4double unitE=CLHEP::MeV, G4double unitData=CLHEP::barn, G4int minZ=1, G4int maxZ=99)
G4int	SelectRandomAtom (const G4MaterialCutsCouple *couple, G4double e) const
const G4Element *	SelectRandomElement (const G4MaterialCutsCouple *material, G4double e) const
G4int	SelectRandomShell (G4int Z, G4double e) const
G4VEMDataSet *	BuildMeanFreePathForMaterials (const G4DataVector *energyCuts=0)
G4double	FindValue (G4int Z, G4double e) const
G4double	FindValue (G4int Z, G4double e, G4int shellIndex) const
G4double	ValueForMaterial (const G4Material *material, G4double e) const
void	LoadData (const G4String &dataFile)
void	LoadNonLogData (const G4String &dataFile)
void	LoadShellData (const G4String &dataFile)
void	PrintData () const
void	Clear ()

Protected Member Functions
G4int	NumberOfComponents (G4int Z) const
void	ActiveElements ()
virtual std::vector< G4VEMDataSet * > *	BuildCrossSectionsForMaterials (const G4DataVector &energyVector, const G4DataVector *energyCuts=0)=0
virtual G4VDataSetAlgorithm *	CreateInterpolation ()
const G4VDataSetAlgorithm *	GetInterpolation () const

Detailed Description

Definition at line 63 of file G4VCrossSectionHandler.hh.

Constructor & Destructor Documentation

G4VCrossSectionHandler() [1/2]

G4VCrossSectionHandler::G4VCrossSectionHandler

(

)

Definition at line 87 of file G4VCrossSectionHandler.cc.

{
  crossSections = 0;
  interpolation = 0;
  Initialise();
  ActiveElements();
}

G4VCrossSectionHandler() [2/2]

G4VCrossSectionHandler::G4VCrossSectionHandler	(	G4VDataSetAlgorithm *	interpolation,
		G4double	minE = 250*CLHEP::eV,
		G4double	maxE = 100*CLHEP::GeV,
		G4int	nBins = 200,
		G4double	unitE = CLHEP::MeV,
		G4double	unitData = CLHEP::barn,
		G4int	minZ = 1,
		G4int	maxZ = 99
	)

Definition at line 96 of file G4VCrossSectionHandler.cc.

  : interpolation(algorithm), eMin(minE), eMax(maxE), nBins(bins),
    unit1(unitE), unit2(unitData), zMin(minZ), zMax(maxZ)
{
  crossSections = 0;
  ActiveElements();
}

~G4VCrossSectionHandler()

G4VCrossSectionHandler::~G4VCrossSectionHandler ( )

virtual

Definition at line 111 of file G4VCrossSectionHandler.cc.

{
  delete interpolation;
  interpolation = 0;
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::iterator pos;
 
  for (pos = dataMap.begin(); pos != dataMap.end(); ++pos)
    {
      // The following is a workaround for STL ObjectSpace implementation, 
      // which does not support the standard and does not accept 
      // the syntax pos->second
      // G4VEMDataSet* dataSet = pos->second;
      G4VEMDataSet* dataSet = (*pos).second;
      delete dataSet;
    }
 
  if (crossSections != 0)
    {
      size_t n = crossSections->size();
      for (size_t i=0; i<n; i++)
    {
      delete (*crossSections)[i];
    }
      delete crossSections;
      crossSections = 0;
    }
}

Member Function Documentation

ActiveElements()

void G4VCrossSectionHandler::ActiveElements ( )

protected

Definition at line 694 of file G4VCrossSectionHandler.cc.

{
  const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
  if (materialTable == 0)
      G4Exception("G4VCrossSectionHandler::ActiveElements",
            "em1001",FatalException,"no MaterialTable found");
 
  G4int nMaterials = G4Material::GetNumberOfMaterials();
 
  for (G4int mLocal2=0; mLocal2<nMaterials; mLocal2++)
    {
      const G4Material* material= (*materialTable)[mLocal2];
      const G4ElementVector* elementVector = material->GetElementVector();
      const G4int nElements = material->GetNumberOfElements();
 
      for (G4int iEl=0; iEl<nElements; iEl++)
    {
      G4Element* element = (*elementVector)[iEl];
      G4double Z = element->GetZ();
      if (!(activeZ.contains(Z)) && Z >= zMin && Z <= zMax)
        {
          activeZ.push_back(Z);
        }
    }
    }
}

Referenced by Clear(), and G4VCrossSectionHandler().

BuildCrossSectionsForMaterials()

virtual std::vector< G4VEMDataSet * > * G4VCrossSectionHandler::BuildCrossSectionsForMaterials ( const G4DataVector &  energyVector, const G4DataVector *  energyCuts = 0  )

protectedpure virtual

Implemented in G4BremsstrahlungCrossSectionHandler, G4eIonisationCrossSectionHandler, G4CrossSectionHandler, and G4eCrossSectionHandler.

Referenced by BuildMeanFreePathForMaterials().

BuildMeanFreePathForMaterials()

G4VEMDataSet * G4VCrossSectionHandler::BuildMeanFreePathForMaterials

(

const G4DataVector *

energyCuts = 0

)

Definition at line 462 of file G4VCrossSectionHandler.cc.

{
  // Builds a CompositeDataSet containing the mean free path for each material
  // in the material table
 
  G4DataVector energyVector;
  G4double dBin = std::log10(eMax/eMin) / nBins;
 
  for (G4int i=0; i<nBins+1; i++)
    {
      energyVector.push_back(std::pow(10., std::log10(eMin)+i*dBin));
    }
 
  // Factory method to build cross sections in derived classes,
  // related to the type of physics process
 
  if (crossSections != 0)
    {  // Reset the list of cross sections
      std::vector<G4VEMDataSet*>::iterator mat;
      if (! crossSections->empty())
    {
      for (mat = crossSections->begin(); mat!= crossSections->end(); ++mat)
        {
          G4VEMDataSet* set = *mat;
          delete set;
          set = 0;
        }
      crossSections->clear();
      delete crossSections;
      crossSections = 0;
    }
    }
 
  crossSections = BuildCrossSectionsForMaterials(energyVector,energyCuts);
 
  if (crossSections == 0)
    {
      G4Exception("G4VCrossSectionHandler::BuildMeanFreePathForMaterials",
            "em1010",FatalException,"crossSections = 0");
      return 0;
    }
 
  G4VDataSetAlgorithm* algo = CreateInterpolation();
  G4VEMDataSet* materialSet = new G4CompositeEMDataSet(algo);
  //G4cout << "G4VCrossSectionHandler  new dataset " << materialSet << G4endl; 
 
  G4DataVector* energies;
  G4DataVector* data;
  G4DataVector* log_energies;
  G4DataVector* log_data;
 
  
  const G4ProductionCutsTable* theCoupleTable=
        G4ProductionCutsTable::GetProductionCutsTable();
  size_t numOfCouples = theCoupleTable->GetTableSize();
 
 
  for (size_t mLocal=0; mLocal<numOfCouples; mLocal++)
    {
      energies = new G4DataVector;
      data = new G4DataVector;
      log_energies = new G4DataVector;
      log_data = new G4DataVector;
      for (G4int bin=0; bin<nBins; bin++)
    {
      G4double energy = energyVector[bin];
      energies->push_back(energy);
          log_energies->push_back(std::log10(energy));
      G4VEMDataSet* matCrossSet = (*crossSections)[mLocal];
      G4double materialCrossSection = 0.0;
          G4int nElm = matCrossSet->NumberOfComponents();
          for(G4int j=0; j<nElm; j++) {
            materialCrossSection += matCrossSet->GetComponent(j)->FindValue(energy);
      }
 
      if (materialCrossSection > 0.)
        {
          data->push_back(1./materialCrossSection);
              log_data->push_back(std::log10(1./materialCrossSection));
        }
      else
        {
          data->push_back(DBL_MAX);
              log_data->push_back(std::log10(DBL_MAX));
        }
    }
      G4VDataSetAlgorithm* algoLocal = CreateInterpolation();
 
      //G4VEMDataSet* dataSet = new G4EMDataSet(m,energies,data,algo,1.,1.);
 
      G4VEMDataSet* dataSet = new G4EMDataSet(mLocal,energies,data,log_energies,log_data,algoLocal,1.,1.);
 
      materialSet->AddComponent(dataSet);
    }
 
  return materialSet;
}

Referenced by G4LivermoreIonisationModel::Initialise().

Clear()

void G4VCrossSectionHandler::Clear

(

)

Definition at line 352 of file G4VCrossSectionHandler.cc.

{
  // Reset the map of data sets: remove the data sets from the map 
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::iterator pos;
 
  if(! dataMap.empty())
    {
        for (pos = dataMap.begin(); pos != dataMap.end(); ++pos)
    {
      // The following is a workaround for STL ObjectSpace implementation, 
      // which does not support the standard and does not accept
      // the syntax pos->first or pos->second
      // G4VEMDataSet* dataSet = pos->second;
      G4VEMDataSet* dataSet = (*pos).second;
      delete dataSet;
      dataSet = 0;
      G4int i = (*pos).first;
      dataMap[i] = 0;
    }
    dataMap.clear();
    }
 
  activeZ.clear();
  ActiveElements();
}

Referenced by G4LivermoreIonisationCrossSection::Initialise(), G4LivermoreComptonModifiedModel::Initialise(), and G4LivermoreIonisationModel::Initialise().

CreateInterpolation()

G4VDataSetAlgorithm * G4VCrossSectionHandler::CreateInterpolation ( )

protectedvirtual

Definition at line 721 of file G4VCrossSectionHandler.cc.

{
  G4VDataSetAlgorithm* algorithm = new G4LogLogInterpolation;
  return algorithm;
}

Referenced by G4CrossSectionHandler::BuildCrossSectionsForMaterials(), BuildMeanFreePathForMaterials(), and Initialise().

FindValue() [1/2]

G4double G4VCrossSectionHandler::FindValue	(	G4int	Z,
		G4double	e
	)		const

Definition at line 378 of file G4VCrossSectionHandler.cc.

{
  G4double value = 0.;
  
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::const_iterator pos;
  pos = dataMap.find(Z);
  if (pos!= dataMap.end())
    {
      // The following is a workaround for STL ObjectSpace implementation, 
      // which does not support the standard and does not accept 
      // the syntax pos->first or pos->second
      // G4VEMDataSet* dataSet = pos->second;
      G4VEMDataSet* dataSet = (*pos).second;
      value = dataSet->FindValue(energy);
    }
  else
    {
      G4cout << "WARNING: G4VCrossSectionHandler::FindValue did not find Z = "
         << Z << G4endl;
    }
  return value;
}

Referenced by G4BremsstrahlungCrossSectionHandler::BuildCrossSectionsForMaterials(), G4eIonisationCrossSectionHandler::BuildCrossSectionsForMaterials(), G4CrossSectionHandler::BuildCrossSectionsForMaterials(), G4LivermoreComptonModifiedModel::ComputeCrossSectionPerAtom(), G4LivermoreIonisationModel::ComputeDEDXPerVolume(), G4LivermoreIonisationCrossSection::CrossSection(), G4BremsstrahlungCrossSectionHandler::GetCrossSectionAboveThresholdForElement(), G4eIonisationCrossSectionHandler::GetCrossSectionAboveThresholdForElement(), SelectRandomShell(), and ValueForMaterial().

FindValue() [2/2]

G4double G4VCrossSectionHandler::FindValue	(	G4int	Z,
		G4double	e,
		G4int	shellIndex
	)		const

Definition at line 401 of file G4VCrossSectionHandler.cc.

{
  G4double value = 0.;
 
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::const_iterator pos;
  pos = dataMap.find(Z);
  if (pos!= dataMap.end())
    {
      // The following is a workaround for STL ObjectSpace implementation, 
      // which does not support the standard and does not accept 
      // the syntax pos->first or pos->second
      // G4VEMDataSet* dataSet = pos->second;
      G4VEMDataSet* dataSet = (*pos).second;
      if (shellIndex >= 0) 
    {
      G4int nComponents = dataSet->NumberOfComponents();
      if(shellIndex < nComponents)    
        // - MGP - Why doesn't it use G4VEMDataSet::FindValue directly?
        value = dataSet->GetComponent(shellIndex)->FindValue(energy);
      else 
        {
          G4cout << "WARNING: G4VCrossSectionHandler::FindValue did not find"
             << " shellIndex= " << shellIndex
             << " for  Z= "
             << Z << G4endl;
        }
    } else {
      value = dataSet->FindValue(energy);
    }
    }
  else
    {
      G4cout << "WARNING: G4VCrossSectionHandler::FindValue did not find Z = "
         << Z << G4endl;
    }
  return value;
}

GetInterpolation()

const G4VDataSetAlgorithm * G4VCrossSectionHandler::GetInterpolation ( ) const

inlineprotected

Definition at line 125 of file G4VCrossSectionHandler.hh.

{ return interpolation; }

Initialise()

void G4VCrossSectionHandler::Initialise	(	G4VDataSetAlgorithm *	interpolation = 0,
		G4double	minE = 250*CLHEP::eV,
		G4double	maxE = 100*CLHEP::GeV,
		G4int	numberOfBins = 200,
		G4double	unitE = CLHEP::MeV,
		G4double	unitData = CLHEP::barn,
		G4int	minZ = 1,
		G4int	maxZ = 99
	)

Definition at line 139 of file G4VCrossSectionHandler.cc.

{
  if (algorithm != 0) 
    {
      delete interpolation;
      interpolation = algorithm;
    }
  else
    {
      delete interpolation;
      interpolation = CreateInterpolation();
    }
 
  eMin = minE;
  eMax = maxE;
  nBins = numberOfBins;
  unit1 = unitE;
  unit2 = unitData;
  zMin = minZ;
  zMax = maxZ;
}

Referenced by G4eCrossSectionHandler::G4eCrossSectionHandler(), G4eIonisationCrossSectionHandler::G4eIonisationCrossSectionHandler(), and G4VCrossSectionHandler().

LoadData()

void G4VCrossSectionHandler::LoadData

(

const G4String &

dataFile

)

Definition at line 186 of file G4VCrossSectionHandler.cc.

{
  size_t nZ = activeZ.size();
  for (size_t i=0; i<nZ; i++)
    {
      G4int Z = (G4int) activeZ[i];
 
      // Build the complete string identifying the file with the data set
      
      char* path = std::getenv("G4LEDATA");
      if (!path)
    { 
          G4Exception("G4VCrossSectionHandler::LoadData",
            "em0006",FatalException,"G4LEDATA environment variable not set");
      return;
    }
      
      std::ostringstream ost;
      ost << path << '/' << fileName << Z << ".dat";
      std::ifstream file(ost.str().c_str());
      std::filebuf* lsdp = file.rdbuf();
       
      if (! (lsdp->is_open()) )
    {
      G4String excep = "data file: " + ost.str() + " not found";
          G4Exception("G4VCrossSectionHandler::LoadData",
            "em0003",FatalException,excep);
    }
      G4double a = 0;
      G4int k = 0;
      G4int nColumns = 2;
 
      G4DataVector* orig_reg_energies = new G4DataVector;
      G4DataVector* orig_reg_data = new G4DataVector;
      G4DataVector* log_reg_energies = new G4DataVector;
      G4DataVector* log_reg_data = new G4DataVector;
 
      do
    {
      file >> a;
 
          if (a==0.) a=1e-300;
 
      // The file is organized into four columns:
      // 1st column contains the values of energy
      // 2nd column contains the corresponding data value
      // The file terminates with the pattern: -1   -1
      //                                       -2   -2
          //
      if (a != -1 && a != -2)
        {
          if (k%nColumns == 0)
                {
         orig_reg_energies->push_back(a*unit1);
                 log_reg_energies->push_back(std::log10(a)+std::log10(unit1));
                }
          else if (k%nColumns == 1)
                {
         orig_reg_data->push_back(a*unit2);
                 log_reg_data->push_back(std::log10(a)+std::log10(unit2));
                }
              k++;
        }
    } 
      while (a != -2); // End of File
      
      file.close();
      G4VDataSetAlgorithm* algo = interpolation->Clone();
 
      G4VEMDataSet* dataSet = new G4EMDataSet(Z,orig_reg_energies,orig_reg_data,log_reg_energies,log_reg_data,algo);
 
      dataMap[Z] = dataSet;
 
    }
}

Referenced by G4LivermoreComptonModifiedModel::Initialise().

LoadNonLogData()

void G4VCrossSectionHandler::LoadNonLogData

(

const G4String &

dataFile

)

Definition at line 263 of file G4VCrossSectionHandler.cc.

{
  size_t nZ = activeZ.size();
  for (size_t i=0; i<nZ; i++)
    {
      G4int Z = (G4int) activeZ[i];
 
      // Build the complete string identifying the file with the data set
      
      char* path = std::getenv("G4LEDATA");
      if (!path)
    { 
          G4Exception("G4VCrossSectionHandler::LoadNonLogData",
            "em0006",FatalException,"G4LEDATA environment variable not set");
      return;
    }
      
      std::ostringstream ost;
      ost << path << '/' << fileName << Z << ".dat";
      std::ifstream file(ost.str().c_str());
      std::filebuf* lsdp = file.rdbuf();
       
      if (! (lsdp->is_open()) )
    {
      G4String excep = "data file: " + ost.str() + " not found";
          G4Exception("G4VCrossSectionHandler::LoadNonLogData",
            "em0003",FatalException,excep);
    }
      G4double a = 0;
      G4int k = 0;
      G4int nColumns = 2;
 
      G4DataVector* orig_reg_energies = new G4DataVector;
      G4DataVector* orig_reg_data = new G4DataVector;
 
      do
    {
      file >> a;
 
      // The file is organized into four columns:
      // 1st column contains the values of energy
      // 2nd column contains the corresponding data value
      // The file terminates with the pattern: -1   -1
      //                                       -2   -2
          //
      if (a != -1 && a != -2)
        {
          if (k%nColumns == 0)
                {
         orig_reg_energies->push_back(a*unit1);
                }
          else if (k%nColumns == 1)
                {
         orig_reg_data->push_back(a*unit2);
                }
              k++;
        }
    } 
      while (a != -2); // End of File
      
      file.close();
      G4VDataSetAlgorithm* algo = interpolation->Clone();
 
      G4VEMDataSet* dataSet = new G4EMDataSet(Z,orig_reg_energies,orig_reg_data,algo);
 
      dataMap[Z] = dataSet;
 
    }
}

LoadShellData()

void G4VCrossSectionHandler::LoadShellData

(

const G4String &

dataFile

)

Definition at line 333 of file G4VCrossSectionHandler.cc.

{
  size_t nZ = activeZ.size();
  for (size_t i=0; i<nZ; i++)
    {
      G4int Z = (G4int) activeZ[i];
      
      G4VDataSetAlgorithm* algo = interpolation->Clone();
      G4VEMDataSet* dataSet = new G4ShellEMDataSet(Z, algo);
 
      dataSet->LoadData(fileName);
      
      dataMap[Z] = dataSet;
    }
}

Referenced by G4LivermoreIonisationCrossSection::Initialise(), and G4LivermoreIonisationModel::Initialise().

NumberOfComponents()

G4int G4VCrossSectionHandler::NumberOfComponents ( G4int  Z ) const

protected

Definition at line 727 of file G4VCrossSectionHandler.cc.

{
  G4int n = 0;
 
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::const_iterator pos;
  pos = dataMap.find(Z);
  if (pos!= dataMap.end())
    {
      G4VEMDataSet* dataSet = (*pos).second;
      n = dataSet->NumberOfComponents();
    }
  else
    {
      G4cout << "WARNING: G4VCrossSectionHandler::NumberOfComponents did not "
             << "find Z = "
             << Z << G4endl;
    }
  return n;
}

Referenced by G4eIonisationCrossSectionHandler::BuildCrossSectionsForMaterials(), and G4eIonisationCrossSectionHandler::GetCrossSectionAboveThresholdForElement().

PrintData()

void G4VCrossSectionHandler::PrintData

(

)

const

Definition at line 165 of file G4VCrossSectionHandler.cc.

{
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::const_iterator pos;
 
  for (pos = dataMap.begin(); pos != dataMap.end(); pos++)
    {
      // The following is a workaround for STL ObjectSpace implementation, 
      // which does not support the standard and does not accept 
      // the syntax pos->first or pos->second
      // G4int z = pos->first;
      // G4VEMDataSet* dataSet = pos->second;
      G4int z = (*pos).first;
      G4VEMDataSet* dataSet = (*pos).second;     
      G4cout << "---- Data set for Z = "
         << z
         << G4endl;
      dataSet->PrintData();
      G4cout << "--------------------------------------------------" << G4endl;
    }
}

Referenced by G4LivermoreIonisationModel::Initialise().

SelectRandomAtom()

G4int G4VCrossSectionHandler::SelectRandomAtom	(	const G4MaterialCutsCouple *	couple,
		G4double	e
	)		const

Definition at line 561 of file G4VCrossSectionHandler.cc.

{
  // Select randomly an element within the material, according to the weight
  // determined by the cross sections in the data set
 
  const G4Material* material = couple->GetMaterial();
  G4int nElements = material->GetNumberOfElements();
 
  // Special case: the material consists of one element
  if (nElements == 1)
    {
      G4int Z = (G4int) material->GetZ();
      return Z;
    }
 
  // Composite material
 
  const G4ElementVector* elementVector = material->GetElementVector();
  size_t materialIndex = couple->GetIndex();
 
  G4VEMDataSet* materialSet = (*crossSections)[materialIndex];
  G4double materialCrossSection0 = 0.0;
  G4DataVector cross;
  cross.clear();
  for ( G4int i=0; i < nElements; i++ )
    {
      G4double cr = materialSet->GetComponent(i)->FindValue(e);
      materialCrossSection0 += cr;
      cross.push_back(materialCrossSection0);
    }
 
  G4double random = G4UniformRand() * materialCrossSection0;
 
  for (G4int k=0 ; k < nElements ; k++ )
    {
      if (random <= cross[k]) return (G4int) (*elementVector)[k]->GetZ();
    }
  // It should never get here
  return 0;
}

Referenced by G4LivermoreIonisationModel::SampleSecondaries().

SelectRandomElement()

const G4Element * G4VCrossSectionHandler::SelectRandomElement	(	const G4MaterialCutsCouple *	material,
		G4double	e
	)		const

Definition at line 603 of file G4VCrossSectionHandler.cc.

{
  // Select randomly an element within the material, according to the weight determined
  // by the cross sections in the data set
 
  const G4Material* material = couple->GetMaterial();
  G4Element* nullElement = 0;
  G4int nElements = material->GetNumberOfElements();
  const G4ElementVector* elementVector = material->GetElementVector();
 
  // Special case: the material consists of one element
  if (nElements == 1)
    {
      G4Element* element = (*elementVector)[0];
      return element;
    }
  else
    {
      // Composite material
 
      size_t materialIndex = couple->GetIndex();
 
      G4VEMDataSet* materialSet = (*crossSections)[materialIndex];
      G4double materialCrossSection0 = 0.0;
      G4DataVector cross;
      cross.clear();
      for (G4int i=0; i<nElements; i++)
        {
          G4double cr = materialSet->GetComponent(i)->FindValue(e);
          materialCrossSection0 += cr;
          cross.push_back(materialCrossSection0);
        }
 
      G4double random = G4UniformRand() * materialCrossSection0;
 
      for (G4int k=0 ; k < nElements ; k++ )
        {
          if (random <= cross[k]) return (*elementVector)[k];
        }
      // It should never end up here
      G4cout << "G4VCrossSectionHandler::SelectRandomElement - no element found" << G4endl;
      return nullElement;
    }
}

SelectRandomShell()

G4int G4VCrossSectionHandler::SelectRandomShell	(	G4int	Z,
		G4double	e
	)		const

Definition at line 649 of file G4VCrossSectionHandler.cc.

{
  // Select randomly a shell, according to the weight determined by the cross sections
  // in the data set
 
  // Note for later improvement: it would be useful to add a cache mechanism for already
  // used shells to improve performance
 
  G4int shell = 0;
 
  G4double totCrossSection = FindValue(Z,e);
  G4double random = G4UniformRand() * totCrossSection;
  G4double partialSum = 0.;
 
  G4VEMDataSet* dataSet = 0;
  std::map<G4int,G4VEMDataSet*,std::less<G4int> >::const_iterator pos;
  pos = dataMap.find(Z);
  // The following is a workaround for STL ObjectSpace implementation,
  // which does not support the standard and does not accept
  // the syntax pos->first or pos->second
  // if (pos != dataMap.end()) dataSet = pos->second;
  if (pos != dataMap.end()) 
    dataSet = (*pos).second;
  else
    {
      G4Exception("G4VCrossSectionHandler::SelectRandomShell",
            "em1011",FatalException,"unable to load the dataSet");
      return 0;
    }
 
  size_t nShells = dataSet->NumberOfComponents();
  for (size_t i=0; i<nShells; i++)
    {
      const G4VEMDataSet* shellDataSet = dataSet->GetComponent(i);
      if (shellDataSet != 0)
    {
      G4double value = shellDataSet->FindValue(e);
      partialSum += value;
      if (random <= partialSum) return i;
    }
    }
  // It should never get here
  return shell;
}

Referenced by G4LivermoreIonisationModel::SampleSecondaries().

ValueForMaterial()

G4double G4VCrossSectionHandler::ValueForMaterial	(	const G4Material *	material,
		G4double	e
	)		const

Definition at line 441 of file G4VCrossSectionHandler.cc.

{
  G4double value = 0.;
 
  const G4ElementVector* elementVector = material->GetElementVector();
  const G4double* nAtomsPerVolume = material->GetVecNbOfAtomsPerVolume();
  G4int nElements = material->GetNumberOfElements();
 
  for (G4int i=0 ; i<nElements ; i++)
    {
      G4int Z = (G4int) (*elementVector)[i]->GetZ();
      G4double elementValue = FindValue(Z,energy);
      G4double nAtomsVol = nAtomsPerVolume[i];
      value += nAtomsVol * elementValue;
    }
 
  return value;
}

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The documentation for this class was generated from the following files:

• G4VCrossSectionHandler.hh
• G4VCrossSectionHandler.cc