#include <G4EMDissociationCrossSection.hh>

Inheritance diagram for G4EMDissociationCrossSection:

Public Member Functions
	G4EMDissociationCrossSection ()

	~G4EMDissociationCrossSection ()

virtual G4bool	IsElementApplicable (const G4DynamicParticle , G4int Z, const G4Material )

virtual G4double	GetElementCrossSection (const G4DynamicParticle , G4int Z, const G4Material )

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=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	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

virtual G4int	GetVerboseLevel () const

virtual 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 79 of file G4EMDissociationCrossSection.hh.

Constructor & Destructor Documentation

G4EMDissociationCrossSection::G4EMDissociationCrossSection ( )

Definition at line 79 of file G4EMDissociationCrossSection.cc.

References python.hepunit::fermi, and python.hepunit::MeV.

  : 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 ( )

Definition at line 98 of file G4EMDissociationCrossSection.cc.

 {
   delete thePhotonSpectrum;
 }

Member Function Documentation

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

Definition at line 165 of file G4EMDissociationCrossSection.cc.

References python.hepunit::amu_c2, G4EMDissociationSpectrum::GetGeneralE1Spectrum(), G4EMDissociationSpectrum::GetGeneralE2Spectrum(), python.hepunit::hbarc, python.hepunit::MeV, python.hepunit::microbarn, python.hepunit::millibarn, and G4PhysicsFreeVector::PutValue().

Referenced by GetCrossSectionForTarget().

 {
 //
 //
 // 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 = std::pow(AP,1.0/3.0);
   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;
 }

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

Definition at line 218 of file G4EMDissociationCrossSection.cc.

References GetCrossSectionForProjectile().

 {
 //
 // 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);
 }

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

virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 125 of file G4EMDissociationCrossSection.cc.

References test::b, CLHEP::HepLorentzVector::beta(), G4DynamicParticle::Get4Momentum(), G4NistManager::GetAtomicMassAmu(), G4ParticleDefinition::GetBaryonNumber(), G4DynamicParticle::GetDefinition(), G4ParticleDefinition::GetPDGCharge(), and G4NistManager::Instance().

 {
   // VI protection for Hydrogen
   if(1 >= Z) { return 0.0; }
      
   //
   // Get relevant information about the projectile and target (A, Z) and
   // velocity of the projectile.
   //
   G4ParticleDefinition *definitionP = theDynamicParticle->GetDefinition();
   G4double AP   = definitionP->GetBaryonNumber();
   G4double ZP   = definitionP->GetPDGCharge();
   G4double b    = theDynamicParticle->Get4Momentum().beta();
   
   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;
 }

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

Definition at line 232 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 < 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*std::exp(-0.075*Z);
     if (p1 < p2) p = p1;
     else         p = p2;
   }
 
   return p;
 }

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

virtual

Reimplemented from G4VCrossSectionDataSet.

Definition at line 105 of file G4EMDissociationCrossSection.cc.

References G4DynamicParticle::GetDefinition(), and G4ParticleTable::GetParticleTable().

 {
 //
 // The condition for the applicability of this class is that the projectile
 // must be an ion and the target must have more than one nucleon.  In reality
 // the value of A for either the projectile or target could be much higher,
 // since for cases where both he projectile and target are medium to small
 // Z, the probability of the EMD process is, I think, VERY small.
 //
   if (G4ParticleTable::GetParticleTable()->GetIonTable()->IsIon(part->GetDefinition())) {
     return true;
   } else {
     return false;
   }
 }

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation