G4ChargeExchangeXS Class Reference

#include <G4ChargeExchangeXS.hh>

Inheritance diagram for G4ChargeExchangeXS:

Public Member Functions
	G4ChargeExchangeXS ()
	~G4ChargeExchangeXS () override=default
G4bool	IsIsoApplicable (const G4DynamicParticle *, G4int Z, G4int A, const G4Element *, const G4Material *) override
G4double	GetIsoCrossSection (const G4DynamicParticle *, G4int Z, G4int A, const G4Isotope *iso, const G4Element *elm, const G4Material *mat) override
void	CrossSectionDescription (std::ostream &) const override
const G4ParticleDefinition *	SampleSecondaryType (const G4ParticleDefinition *, const G4int Z, const G4int A)
void	SetEnergyLimit (G4double val)
void	SetCrossSectionFactor (G4double val)
G4ChargeExchangeXS &	operator= (const G4ChargeExchangeXS &right)=delete
	G4ChargeExchangeXS (const G4ChargeExchangeXS &)=delete
Public Member Functions inherited from G4VCrossSectionDataSet
	G4VCrossSectionDataSet (const G4String &nam="")
virtual	~G4VCrossSectionDataSet ()
virtual G4bool	IsElementApplicable (const G4DynamicParticle *, G4int Z, const G4Material *mat=nullptr)
G4double	GetCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=nullptr)
G4double	ComputeCrossSection (const G4DynamicParticle *, const G4Element *, const G4Material *mat=nullptr)
virtual G4double	ComputeCrossSectionPerElement (G4double kinEnergy, G4double loge, const G4ParticleDefinition *, const G4Element *, const G4Material *mat=nullptr)
virtual G4double	GetElementCrossSection (const G4DynamicParticle *, G4int Z, const G4Material *mat=nullptr)
virtual G4double	ComputeIsoCrossSection (G4double kinEnergy, G4double loge, const G4ParticleDefinition *, G4int Z, G4int A, const G4Isotope *iso=nullptr, const G4Element *elm=nullptr, const G4Material *mat=nullptr)
virtual const G4Isotope *	SelectIsotope (const G4Element *, G4double kinEnergy, G4double logE)
virtual void	BuildPhysicsTable (const G4ParticleDefinition &)
virtual void	DumpPhysicsTable (const G4ParticleDefinition &)
virtual void	SetVerboseLevel (G4int value)
G4double	GetMinKinEnergy () const
void	SetMinKinEnergy (G4double value)
G4double	GetMaxKinEnergy () const
void	SetMaxKinEnergy (G4double value)
bool	ForAllAtomsAndEnergies () const
void	SetForAllAtomsAndEnergies (G4bool val)
const G4String &	GetName () const
void	SetName (const G4String &nam)
G4VCrossSectionDataSet &	operator= (const G4VCrossSectionDataSet &right)=delete
	G4VCrossSectionDataSet (const G4VCrossSectionDataSet &)=delete

Additional Inherited Members
Protected Attributes inherited from G4VCrossSectionDataSet
G4int	verboseLevel
G4String	name

Detailed Description

Definition at line 65 of file G4ChargeExchangeXS.hh.

Constructor & Destructor Documentation

G4ChargeExchangeXS() [1/2]

G4ChargeExchangeXS::G4ChargeExchangeXS

(

)

Definition at line 70 of file G4ChargeExchangeXS.cc.

{
  if (verboseLevel > 1) {
    G4cout  << "G4ChargeExchangeXS::G4ChargeExchangeXS" << G4endl;
  }
  g4calc = G4Pow::GetInstance();
  auto table = G4ParticleTable::GetParticleTable();
  const G4String nam[5] = {"pi0", "eta", "eta_prime", "omega", "f2(1270)"};
  for (G4int i=0; i<5; ++i) {
    fPionSecPD[i] = table->FindParticle(nam[i]);
    if (nullptr == fPionSecPD[i]) {
      G4ExceptionDescription ed;
      ed << "### meson " << nam[i] << " is not found out in the particle table";
      G4Exception("G4ChargeExchangeXS::G4ChargeExchangeXS()","had044",
                  FatalException, ed,"");
    }
  }
}

~G4ChargeExchangeXS()

G4ChargeExchangeXS::~G4ChargeExchangeXS ( )

overridedefault

G4ChargeExchangeXS() [2/2]

G4ChargeExchangeXS::G4ChargeExchangeXS ( const G4ChargeExchangeXS & )

delete

Member Function Documentation

CrossSectionDescription()

void G4ChargeExchangeXS::CrossSectionDescription ( std::ostream & outFile ) const

overridevirtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 90 of file G4ChargeExchangeXS.cc.

{
  outFile << "G4ChargeExchangeXS calculates charge exchange cross section for "
          << "pi+, pi-, K+, K-, KL\n";
}

GetIsoCrossSection()

G4double G4ChargeExchangeXS::GetIsoCrossSection ( const G4DynamicParticle * aParticle, G4int Z, G4int A, const G4Isotope * iso, const G4Element * elm, const G4Material * mat )

overridevirtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 104 of file G4ChargeExchangeXS.cc.

{
  G4double result = 0.0;
  const G4double pE = aParticle->GetTotalEnergy();
  if (pE <= fEnergyLimit) { return result; } 
  auto part = aParticle->GetDefinition();
  G4int pdg = part->GetPDGEncoding();   
 
  // Get or calculate the nucleus mass, particle mass,particle kinetic energy 
  // and particle total energy 
  G4double tM = G4NucleiProperties::GetNuclearMass(A, Z);
  G4double pM = part->GetPDGMass(); 
 
  // Calculate s(lorentz invariant)
  G4double lorentz_s = tM*tM + 2*tM*pE +  pM*pM;
  if (lorentz_s <= (tM + pM)*(tM + pM)) { return result; }
 
  // For unit conversion 
  const G4double inv1e7 = 1e-7;
  const G4double fact = 1e-30*CLHEP::cm2;
  const G4double pfact = 0.1/CLHEP::GeV;
  const G4double kfact = 56.3*fact;
 
  G4double logA = g4calc->logZ(A);
 
  // The approximation of Glauber-Gribov formula -> extend it from interaction with 
  // proton to nuclei  Z^(2/3). The factor g4calc->powA(A,-beta_prime_pi*G4Log(A))
  // takes into account absorption of pi0 and eta 
  // pi- + p -> sum of (pi0 + eta) + n 
  if (pdg == -211) {
    const G4double z23 = g4calc->Z23(Z);
    const G4int z = A/2;
    const G4double a23 = g4calc->Z23(z);
    const G4double x = lorentz_s*inv1e7;
    G4double sum = 122.*z23*g4calc->powA(x, -1.23)*g4calc->powZ(A,-beta_prime_pi*logA);
    fXSecPion[0] = sum;
    sum += 31.*z23*g4calc->powA(x, -1.53)*g4calc->powZ(A,-beta_prime_eta*logA);
    fXSecPion[1] = sum;
    const G4double logX = G4Log(x);
    for (G4int i=2; i<5; ++i) {
      sum += piA[i]*z23*g4calc->powA(x, -pAP[i])*(1.0 + pG0[i] + pG1[i]*logX)
    *g4calc->powA(z23, -0.15*a23)/(pC0[i] + pC1[i]*logX);
      fXSecPion[i] = sum; 
    }
    result = sum*fact;
  }
 
  // pi+ + n -> sum of (pi0 + eta) + p
  else if (pdg == 211) {
    const G4double n23 = g4calc->Z23(A - Z);
    const G4int z = A/2;
    const G4double a23 = g4calc->Z23(z);
    const G4double x = lorentz_s*inv1e7;
    G4double sum = 122.*n23*g4calc->powA(x, -1.23)*g4calc->powZ(A,-beta_prime_pi*logA);
    fXSecPion[0] = sum;
    sum += 31.*n23*g4calc->powA(x, -1.53)*g4calc->powZ(A,-beta_prime_eta*logA);
    fXSecPion[1] = sum;
    const G4double logX = G4Log(x);
    for (G4int i=2; i<5; ++i) {
      sum += piA[i]*n23*g4calc->powA(x, -pAP[i])*(1.0 + pG0[i] + pG1[i]*logX)
    *g4calc->powA(n23, -0.15*a23)/(pC0[i] + pC1[i]*logX);
      fXSecPion[i] = sum; 
    }
    result = sum*fact;
  }
 
  // K- + p -> Kbar + n
  else if (pdg == -321){
    // Calculate the momentum of the bombarding particles and convert 
    // it to GeV/c^2 unit
    const G4double p_momentum = std::sqrt(pE*pE - pM*pM)*pfact;
    result = g4calc->Z23(Z)*g4calc->powA(p_momentum, -1.60)*kfact;
  }
 
  // K+ + n -> Kbar + p
  else if (pdg == 321) {
    const G4double p_momentum = std::sqrt(pE*pE - pM*pM)*pfact;
    result = g4calc->Z23(A-Z)*g4calc->powA(p_momentum, -1.60)*kfact;
  }
 
  // KL 
  else if (pdg == 130) {
    // Cross section of K-long = 0.5*(Cross section of K+ + Cross section of K-)
    const G4double p_momentum = std::sqrt(pE*pE - pM*pM)*pfact;
    result = 0.5*(g4calc->Z23(Z) + g4calc->Z23(A-Z))*
      g4calc->powA(p_momentum, -1.60)*kfact;
  }
  
  return result*fFactor;
}

IsIsoApplicable()

G4bool G4ChargeExchangeXS::IsIsoApplicable ( const G4DynamicParticle * , G4int Z, G4int A, const G4Element * , const G4Material *  )

overridevirtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 96 of file G4ChargeExchangeXS.cc.

{
  return true;
}

operator=()

G4ChargeExchangeXS & G4ChargeExchangeXS::operator= ( const G4ChargeExchangeXS & right )

delete

SampleSecondaryType()

const G4ParticleDefinition * G4ChargeExchangeXS::SampleSecondaryType	(	const G4ParticleDefinition *	part,
		const G4int	Z,
		const G4int	A )

Definition at line 199 of file G4ChargeExchangeXS.cc.

{
  const G4ParticleDefinition* pd = nullptr;
  G4int pdg = part->GetPDGEncoding();  
 
  // pi- + p /  pi+ + n  
  if (std::abs(pdg) == 211) {
    const G4double x = fXSecPion[4]*G4UniformRand();
    for (G4int i=0; i<5; ++i) {
      if (x <= fXSecPion[i]) {
        return fPionSecPD[i];
      }
    }
  }
 
  // K- + p /  K+ + n 
  // Equal opportunity of producing k-short and k-long
  else if (std::abs(pdg) == 321) {
    if (G4UniformRand() > 0.5) {
      pd = G4KaonZeroLong::KaonZeroLong(); 
    }
    else {
      pd = G4KaonZeroShort::KaonZeroShort();
    }
  }
 
  // KL + atom 
  else if (std::abs(pdg) == 130) {
    G4double prob = (G4double)Z/(G4double)A;
    if (G4UniformRand() > prob) {
      pd = G4KaonMinus::KaonMinus();
    }
    else {
      pd = G4KaonPlus::KaonPlus();
    }
  }
 
  return pd;
} 

Referenced by G4ChargeExchange::ApplyYourself().

SetCrossSectionFactor()

void G4ChargeExchangeXS::SetCrossSectionFactor ( G4double val )

inline

Definition at line 89 of file G4ChargeExchangeXS.hh.

{ fFactor = val; };

SetEnergyLimit()

void G4ChargeExchangeXS::SetEnergyLimit ( G4double val )

inline

Definition at line 87 of file G4ChargeExchangeXS.hh.

{ fEnergyLimit = val; };

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

• G4ChargeExchangeXS.hh
• G4ChargeExchangeXS.cc