G4PhotoNuclearCrossSection Class Reference

#include <G4PhotoNuclearCrossSection.hh>

Inheritance diagram for G4PhotoNuclearCrossSection:

Public Member Functions
	G4PhotoNuclearCrossSection (const G4String &name="PhotoNuclearXS")
virtual	~G4PhotoNuclearCrossSection ()
virtual void	CrossSectionDescription (std::ostream &) const
virtual G4bool	IsIsoApplicable (const G4DynamicParticle *particle, G4int, G4int, const G4Element *, const G4Material *)
virtual G4double	GetIsoCrossSection (const G4DynamicParticle *, G4int, G4int, const G4Isotope *, const G4Element *, const G4Material *)
Public Member Functions inherited from G4VCrossSectionDataSet
	G4VCrossSectionDataSet (const G4String &nam="")
virtual	~G4VCrossSectionDataSet ()
virtual G4bool	IsElementApplicable (const G4DynamicParticle *, G4int Z, const G4Material *mat=0)
virtual G4bool	IsIsoApplicable (const G4DynamicParticle *, G4int Z, G4int A, const G4Element *elm=0, const G4Material *mat=0)
G4double	GetCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=0)
G4double	ComputeCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=0)
virtual G4double	GetElementCrossSection (const G4DynamicParticle *, G4int Z, const G4Material *mat=0)
virtual G4double	GetIsoCrossSection (const G4DynamicParticle *, G4int Z, G4int A, const G4Isotope *iso=0, const G4Element *elm=0, const G4Material *mat=0)
virtual G4Isotope *	SelectIsotope (const G4Element *, G4double kinEnergy)
virtual void	BuildPhysicsTable (const G4ParticleDefinition &)
virtual void	DumpPhysicsTable (const G4ParticleDefinition &)
virtual void	CrossSectionDescription (std::ostream &) const
void	SetVerboseLevel (G4int value)
G4double	GetMinKinEnergy () const
void	SetMinKinEnergy (G4double value)
G4double	GetMaxKinEnergy () const
void	SetMaxKinEnergy (G4double value)
const G4String &	GetName () const

Additional Inherited Members
Protected Member Functions inherited from G4VCrossSectionDataSet
void	SetName (const G4String &)
Protected Attributes inherited from G4VCrossSectionDataSet
G4int	verboseLevel

Detailed Description

Definition at line 42 of file G4PhotoNuclearCrossSection.hh.

Constructor & Destructor Documentation

G4PhotoNuclearCrossSection()

G4PhotoNuclearCrossSection::G4PhotoNuclearCrossSection

(

const G4String &

name = "PhotoNuclearXS"

)

Definition at line 72 of file G4PhotoNuclearCrossSection.cc.

 : G4VCrossSectionDataSet(nam)
{}

~G4PhotoNuclearCrossSection()

G4PhotoNuclearCrossSection::~G4PhotoNuclearCrossSection ( )

virtual

Definition at line 76 of file G4PhotoNuclearCrossSection.cc.

{
  std::vector<G4double*>::iterator pos;
  for(pos=GDR.begin(); pos<GDR.end(); pos++)
  { delete [] *pos; }
  GDR.clear();
  for(pos=HEN.begin(); pos<HEN.end(); pos++)
  { delete [] *pos; }
  HEN.clear();
}

Member Function Documentation

CrossSectionDescription()

void G4PhotoNuclearCrossSection::CrossSectionDescription ( std::ostream &  outFile ) const

virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 88 of file G4PhotoNuclearCrossSection.cc.

{
  outFile << "G4PhotoNuclearCrossSection provides the total inelastic\n"
          << "cross section for photon interactions with nuclei.  The\n"
          << "cross section is a parameterization of data which covers\n" 
          << "all incident gamma energies.\n";
}

GetIsoCrossSection()

G4double G4PhotoNuclearCrossSection::GetIsoCrossSection ( const G4DynamicParticle *  aPart, G4int  ZZ, G4int  AA, const G4Isotope *  , const G4Element *  , const G4Material *    )

virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 109 of file G4PhotoNuclearCrossSection.cc.

{
  static const G4double THmin=2.;          // minimum Energy Threshold
  static const G4double dE=1.;             // step for the GDR table
  static const G4int    nL=105;            // A#of GDResonance points in E 
                                           // (each MeV from 2 to 106)
  static const G4double Emin=THmin+(nL-1)*dE; // minE for the HighE part
  static const G4double Emax=50000.;       // maxE for the HighE part
  static const G4int    nH=224;            // A#of HResonance points in lnE
  static const G4double milE=std::log(Emin);  // Low logarithm energy for 
                                           // the HighE part
  static const G4double malE=std::log(Emax);  // High logarithm energy 
                                           // (each 2.75 percent)
  static const G4double dlE=(malE-milE)/(nH-1); // Step in logarithm energy 
                                           // in the HighE part
  //
  //static const G4double shd=1.075-.0023*std::log(2.);  // HE PomShadowing(D)
  static const G4double shd=1.0734;                 // HE PomShadowing(D)
  static const G4double shc=0.072;                  // HE Shadowing constant
  static const G4double poc=0.0375;                 // HE Pomeron coefficient
  static const G4double pos=16.5;                   // HE Pomeron shift
  static const G4double reg=.11;                    // HE Reggeon slope
  //static const G4double shp=1.075;                  // HE PomShadowing(P)
 
  // Associative memory for acceleration
 
  static std::vector <G4int> colN;      // N of calculated nuclei
  static std::vector <G4int> colZ;      // Z of calculated nuclei
  static std::vector <G4double> spA;    // shadowing coefficients (A-dependent)
  static std::vector <G4double> eTH;    // energy threshold (A-dependent)
  //
  const G4double Energy = aPart->GetKineticEnergy()/MeV;
  const G4int targetAtomicNumber = AA; //@@ Nat mixture (?!)
  const G4int targZ = ZZ;
  const G4int targN = targetAtomicNumber-targZ;
#ifdef debug
  G4cout << "G4PhotoNuclearCrossSection::GetCS:N=" << targN << ",Z=" 
         << targZ << ",E=" << Energy << G4endl;
#endif
  if (Energy<THmin) return 0.;
  G4double sigma=0.;
  if( aPart->GetDefinition()->GetPDGEncoding() == 22 )
  {
    G4double A=targN+targZ;
    if(targN!=lastN || targZ!=lastZ)   // Otherwise the set of parameters is ready
    {
      lastN = targN;             // The last N of calculated nucleus
      lastZ = targZ;             // The last Z of calculated nucleus
      G4int n=colN.size();       // Size of Associated Memory
      G4bool in=false;           // The nucleus is in the AssocMem DB
      if(n) {
        for(G4int i=0; i<n; i++) {
          if(colN[i]==targN && colZ[i]==targZ) // Calculated nuclei in DB
          {
            in=true;          // The nucleus is found in the AssocMem DB
            lastGDR=GDR[i];   // Pointer to prepared GDR cross sections
            lastHEN=HEN[i];   // Pointer to prepared High Energy cross sections
            lastTH =eTH[i];   // Energy Threshold
            lastSP =spA[i];   // Shadowing coefficient for UHE
          }
    }
      }
#ifdef debug
      G4cout<<"G4PhotoNucCrossSect::GetCS:A="<<A<<",n="<<n<<",in="<<in<<G4endl;
#endif
      if(!in)          // Fill the new set of parameters for the new nucleus
      {
        G4double lnA=std::log(A); // The nucleus is not found in DB. It is new.
        if(A==1.) lastSP=1.;      // The Reggeon shadowing (A=1)
        else lastSP=A*(1.-shc*lnA);      // The Reggeon shadowing
#ifdef debug
        G4cout << "G4PhotoNucCrossSect::GetCS: lnA="
               << lnA << ",lastSP=" << lastSP << G4endl;
#endif
        lastTH=ThresholdEnergy(targZ, targN); // Energy Threshold
#ifdef debug
        G4cout << "G4PhotoNucCrossSect::GetCS: lastTH=" << lastTH << G4endl;
#endif
#ifdef debug3
        if(A==3) G4cout << "G4PhotoNucCrossSect::GetCS: lastTH="
                        << lastTH << ",lastSP=" << lastSP << G4endl;
#endif
        lastGDR = new G4double[nL];  // Allocate memory for the new 
                                     // GDR cross sections
        lastHEN = new G4double[nH];  // Allocate memory for the new 
                                     // HEN cross sections
        G4int er=GetFunctions(A,lastGDR,lastHEN); // new ZeroPosition and 
                                                  // filling of the functions
        if(er<1) G4cerr << "***G4PhotoNucCrossSection::GetCrossSection: A="
                        << A << " failed" << G4endl;
#ifdef debug
        G4cout<<"G4PhotoNucCrossSect::GetCS: GetFunctions er="<<er<<G4endl;
#endif
        colN.push_back(targN);
        colZ.push_back(targZ);
        GDR.push_back(lastGDR);     // added GDR, found by AH 10/7/02
        HEN.push_back(lastHEN);     // added HEN, found by AH 10/7/02
        eTH.push_back(lastTH);      // Threshold Energy
        spA.push_back(lastSP);      // Pomeron Shadowing
      } // End of creation of the new set of parameters
    } // End of parameters udate
 
    //
    // =================== NOW the Magic Formula ===================
    //
    if (Energy<lastTH)
    {
      lastE=Energy;
      lastSig=0.;
      return 0.;
    }
    else if (Energy<Emin)   // GDR region (approximated in E, not in lnE)
    {
#ifdef debug
      G4cout << "G4PNCS::GetCS: before GDR A=" << A 
              << ", nL=" << nL << ",TH=" << THmin << ",dE=" <<dE << G4endl;
#endif
      if(A<=1.) sigma=0.;
      else      sigma=EquLinearFit(Energy,nL,THmin,dE,lastGDR);
#ifdef debugn
      if(sigma<0.) G4cout << "G4PNCS::GetCS:A=" << A << ",E=" << Energy 
                          << ",TH=" << THmin << ",dE=" << dE << G4endl;
#endif
    }
    else if (Energy<Emax)                     // High Energy region
    {
      G4double lE=std::log(Energy);
#ifdef debug
      G4cout << "G4PNCS::GetCS: before HEN nH=" << nH << ",iE=" 
             << milE << ",dlE=" << dlE << G4endl;
#endif
      sigma=EquLinearFit(lE,nH,milE,dlE,lastHEN);
    }
    else               // UHE region (calculation, but not so frequent)
    {
      G4double lE=std::log(Energy);
      //G4double sh=shd;
      //if(A==1.)sh=shp;
      sigma=lastSP*(poc*(lE-pos)+shd*std::exp(-reg*lE));
    }
#ifdef debug
    G4cout<<"G4PNCS::GetCS: sigma="<<sigma<<G4endl;
#endif
#ifdef pdebug
    if(Energy>45000.&&Energy<60000.)G4cout<<"PN::CS:A="<<A<<",E="<<Energy<<",sigma="<<sigma<<G4endl;
#endif
  } // End of "sigma" calculation
  else return 0.;
 
  if(sigma<0.) return 0.;
  return sigma*millibarn;
}

IsIsoApplicable()

G4bool G4PhotoNuclearCrossSection::IsIsoApplicable ( const G4DynamicParticle *  particle, G4int  , G4int  , const G4Element *  , const G4Material *    )

virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 97 of file G4PhotoNuclearCrossSection.cc.

{
  G4bool result = false;
  if( particle->GetDefinition()->GetPDGEncoding()==22) result = true;
  return result;
}

---

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

• G4PhotoNuclearCrossSection.hh
• G4PhotoNuclearCrossSection.cc