#include <G4EMDissociationCrossSection.hh>

Inheritance diagram for G4EMDissociationCrossSection:

Public Member Functions
	G4EMDissociationCrossSection ()
	~G4EMDissociationCrossSection () override
G4bool	IsElementApplicable (const G4DynamicParticle , G4int Z, const G4Material ) override
G4double	GetElementCrossSection (const G4DynamicParticle , G4int Z, const G4Material ) override
G4PhysicsFreeVector *	GetCrossSectionForProjectile (G4double, G4double, G4double, G4double, G4double, G4double)
G4PhysicsFreeVector *	GetCrossSectionForTarget (G4double, G4double, G4double, G4double, G4double, G4double)
G4double	GetWilsonProbabilityForProtonDissociation (G4double, G4double)
Public Member Functions inherited from G4VCrossSectionDataSet
	G4VCrossSectionDataSet (const G4String &nam="")
virtual	~G4VCrossSectionDataSet ()
virtual G4bool	IsIsoApplicable (const G4DynamicParticle , G4int Z, G4int A, const G4Element elm=nullptr, 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	GetIsoCrossSection (const G4DynamicParticle , G4int Z, G4int A, const G4Isotope iso=nullptr, const G4Element elm=nullptr, 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	CrossSectionDescription (std::ostream &) const
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 {0}
G4String	name

Detailed Description

Definition at line 79 of file G4EMDissociationCrossSection.hh.

Constructor & Destructor Documentation

◆ G4EMDissociationCrossSection()

G4EMDissociationCrossSection::G4EMDissociationCrossSection ( )

Definition at line 79 of file G4EMDissociationCrossSection.cc.

 : G4VCrossSectionDataSet("Electromagnetic dissociation")
{
  // This function makes use of the class which can sample the virtual photon
  // spectrum, G4EMDissociationSpectrum.
 
  thePhotonSpectrum = new G4EMDissociationSpectrum();
 
  // Define other constants.
 
  r0      = 1.18 * fermi;
  J       = 36.8 * MeV;
  Qprime  = 17.0 * MeV;
  epsilon = 0.0768;
  xd      = 0.25;
}

◆ ~G4EMDissociationCrossSection()

G4EMDissociationCrossSection::~G4EMDissociationCrossSection ( )

override

Definition at line 98 of file G4EMDissociationCrossSection.cc.

{
  delete thePhotonSpectrum;
}

Member Function Documentation

◆ GetCrossSectionForProjectile()

G4PhysicsFreeVector * G4EMDissociationCrossSection::GetCrossSectionForProjectile	(	G4double	AP,
		G4double	ZP,
		G4double	,
		G4double	ZT,
		G4double	b,
		G4double	bmin )

Definition at line 158 of file G4EMDissociationCrossSection.cc.

{
//
//
// Use Wilson et al's approach to calculate the cross-sections due to the E1
// and E2 moments of the field at the giant dipole and quadrupole resonances
// respectively,  Note that the algorithm is traditionally applied to the
// EMD break-up of the projectile in the field of the target, as is implemented
// here.
//
// Initialise variables and calculate the energies for the GDR and GQR.
//
  G4double AProot3 = G4Pow::GetInstance()->A13(AP);
  G4double u       = 3.0 * J / Qprime / AProot3;
  G4double R0      = r0 * AProot3;
  G4double E_GDR  = hbarc / std::sqrt(0.7*amu_c2*R0*R0/8.0/J*
    (1.0 + u - (1.0 + epsilon + 3.0*u)/(1.0 + epsilon + u)*epsilon));
  G4double E_GQR  = 63.0 * MeV / AProot3;
//
//
// Determine the virtual photon spectra at these energies.
//
  G4double ZTsq = ZT * ZT;
  G4double nE1 = ZTsq *
    thePhotonSpectrum->GetGeneralE1Spectrum(E_GDR, b, bmin);
  G4double nE2 = ZTsq *
    thePhotonSpectrum->GetGeneralE2Spectrum(E_GQR, b, bmin);
//
//
// Now calculate the cross-section of the projectile for interaction with the
// E1 and E2 fields.
//
  G4double sE1 = 60.0 * millibarn * MeV * (AP-ZP)*ZP/AP;
  G4double sE2 = 0.22 * microbarn / MeV * ZP * AProot3 * AProot3;
  if (AP > 100.0)     sE2 *= 0.9;
  else if (AP > 40.0) sE2 *= 0.6;
  else                sE2 *= 0.3;
//
//
// ... and multiply with the intensity of the virtual photon spectra to get
// the probability of interaction.
//
  G4PhysicsFreeVector *theCrossSectionVector = new G4PhysicsFreeVector(2);
  theCrossSectionVector->PutValue(0, E_GDR, sE1*nE1);
  theCrossSectionVector->PutValue(1, E_GQR, sE2*nE2*E_GQR*E_GQR);
 
  return theCrossSectionVector;
}

Referenced by GetCrossSectionForTarget(), and GetElementCrossSection().

◆ GetCrossSectionForTarget()

G4PhysicsFreeVector * G4EMDissociationCrossSection::GetCrossSectionForTarget	(	G4double	AP,
		G4double	ZP,
		G4double	AT,
		G4double	ZT,
		G4double	b,
		G4double	bmin )

Definition at line 211 of file G4EMDissociationCrossSection.cc.

{
//
// This is a cheaky little member function to calculate the probability of
// EMD for the target in the field of the projectile ... just by reversing the
// A and Z's for the participants.
//
  return GetCrossSectionForProjectile (AT, ZT, AP, ZP, b, bmin);
}

Referenced by GetElementCrossSection().

◆ GetElementCrossSection()

G4double G4EMDissociationCrossSection::GetElementCrossSection	(	const G4DynamicParticle *	theDynamicParticle,
		G4int	Z,
		const G4Material *	)

overridevirtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 113 of file G4EMDissociationCrossSection.cc.

{
  // VI protection for Hydrogen
  if(1 >= Z) { return 0.0; }
 
  // Zero cross-section for particles with kinetic energy less than 2 MeV to prevent
  // possible abort signal from bad arithmetic in GetCrossSectionForProjectile
  if ( theDynamicParticle->GetKineticEnergy() < 2.0*CLHEP::MeV ) { return 0.0; }
  
  //
  // Get relevant information about the projectile and target (A, Z) and
  // velocity of the projectile.
  //
  const G4ParticleDefinition *definitionP = theDynamicParticle->GetDefinition();
  G4double AP   = definitionP->GetBaryonNumber();
  G4double ZP   = definitionP->GetPDGCharge();
  G4double b    = theDynamicParticle->GetBeta();
  if (b <= 0.0) { return 0.0; }
  
  G4double AT   = G4NistManager::Instance()->GetAtomicMassAmu(Z);
  G4double ZT   = (G4double)Z;
  G4double bmin = thePhotonSpectrum->GetClosestApproach(AP, ZP, AT, ZT, b);
  //
  //
  // Calculate the cross-section for the projectile and then the target.  The
  // information is returned in a G4PhysicsFreeVector, which separates out the
  // cross-sections for the E1 and E2 moments of the virtual photon field, and
  // the energies (GDR and GQR).
  //
  G4PhysicsFreeVector *theProjectileCrossSections =
    GetCrossSectionForProjectile (AP, ZP, AT, ZT, b, bmin);
  G4double crossSection =
    (*theProjectileCrossSections)[0]+(*theProjectileCrossSections)[1];
  delete theProjectileCrossSections;
  G4PhysicsFreeVector *theTargetCrossSections =
    GetCrossSectionForTarget (AP, ZP, AT, ZT, b, bmin);
  crossSection +=
    (*theTargetCrossSections)[0]+(*theTargetCrossSections)[1];
  delete theTargetCrossSections;
  return crossSection;
}

◆ GetWilsonProbabilityForProtonDissociation()

G4double G4EMDissociationCrossSection::GetWilsonProbabilityForProtonDissociation	(	G4double	A,
		G4double	Z )

Definition at line 225 of file G4EMDissociationCrossSection.cc.

{
//
// This is a simple algorithm to choose whether a proton or neutron is ejected
// from the nucleus in the EMD interaction.
//
  G4double p = 0.0;
  if (Z < 2.0)
    p = 0.0;  // To avoid to remove one proton from hydrogen isotopes
  else if (Z < 6.0)
    p = 0.5;
  else if (Z < 8.0)
    p = 0.6;
  else if (Z < 14.0)
    p = 0.7;
  else
  {
    G4double p1 = (G4double) Z / (G4double) A;
    G4double p2 = 1.95*G4Exp(-0.075*Z);
    if (p1 < p2) p = p1;
    else         p = p2;
  }
 
  return p;
}

◆ IsElementApplicable()

G4bool G4EMDissociationCrossSection::IsElementApplicable	(	const G4DynamicParticle *	,
		G4int	Z,
		const G4Material *	)