G4HadronElastic Class Reference

#include <G4HadronElastic.hh>

Inheritance diagram for G4HadronElastic:

Collaboration diagram for G4HadronElastic:

Public Member Functions
	G4HadronElastic (const G4String &name="hElasticLHEP")
virtual	~G4HadronElastic ()
virtual G4HadFinalState *	ApplyYourself (const G4HadProjectile &aTrack, G4Nucleus &targetNucleus)
virtual G4double	SampleInvariantT (const G4ParticleDefinition *p, G4double plab, G4int Z, G4int A)
void	SetLowestEnergyLimit (G4double value)
G4double	LowestEnergyLimit () const
G4double	ComputeMomentumCMS (const G4ParticleDefinition *p, G4double plab, G4int Z, G4int A)
virtual void	ModelDescription (std::ostream &) const
Public Member Functions inherited from G4HadronicInteraction
	G4HadronicInteraction (const G4String &modelName="HadronicModel")
virtual	~G4HadronicInteraction ()
virtual G4bool	IsApplicable (const G4HadProjectile &aTrack, G4Nucleus &targetNucleus)
G4double	GetMinEnergy () const
G4double	GetMinEnergy (const G4Material *aMaterial, const G4Element *anElement) const
void	SetMinEnergy (G4double anEnergy)
void	SetMinEnergy (G4double anEnergy, const G4Element *anElement)
void	SetMinEnergy (G4double anEnergy, const G4Material *aMaterial)
G4double	GetMaxEnergy () const
G4double	GetMaxEnergy (const G4Material *aMaterial, const G4Element *anElement) const
void	SetMaxEnergy (const G4double anEnergy)
void	SetMaxEnergy (G4double anEnergy, const G4Element *anElement)
void	SetMaxEnergy (G4double anEnergy, const G4Material *aMaterial)
G4int	GetVerboseLevel () const
void	SetVerboseLevel (G4int value)
const G4String &	GetModelName () const
void	DeActivateFor (const G4Material *aMaterial)
void	ActivateFor (const G4Material *aMaterial)
void	DeActivateFor (const G4Element *anElement)
void	ActivateFor (const G4Element *anElement)
G4bool	IsBlocked (const G4Material *aMaterial) const
G4bool	IsBlocked (const G4Element *anElement) const
void	SetRecoilEnergyThreshold (G4double val)
G4double	GetRecoilEnergyThreshold () const
virtual const std::pair < G4double, G4double >	GetFatalEnergyCheckLevels () const
virtual std::pair< G4double, G4double >	GetEnergyMomentumCheckLevels () const
void	SetEnergyMomentumCheckLevels (G4double relativeLevel, G4double absoluteLevel)
virtual void	BuildPhysicsTable (const G4ParticleDefinition &)
virtual void	InitialiseModel ()

Additional Inherited Members
Protected Member Functions inherited from G4HadronicInteraction
void	SetModelName (const G4String &nam)
G4bool	IsBlocked () const
void	Block ()
Protected Attributes inherited from G4HadronicInteraction
G4HadFinalState	theParticleChange
G4int	verboseLevel
G4double	theMinEnergy
G4double	theMaxEnergy
G4bool	isBlocked

Detailed Description

Definition at line 50 of file G4HadronElastic.hh.

Constructor & Destructor Documentation

G4HadronElastic::G4HadronElastic

(

const G4String &

name = "hElasticLHEP"

)

Definition at line 48 of file G4HadronElastic.cc.

  : G4HadronicInteraction(name)
{
  SetMinEnergy( 0.0*GeV );
  SetMaxEnergy( 100.*TeV );
  lowestEnergyLimit= 1.e-6*eV;  

  theProton   = G4Proton::Proton();
  theNeutron  = G4Neutron::Neutron();
  theDeuteron = G4Deuteron::Deuteron();
  theAlpha    = G4Alpha::Alpha();
  //Description();
}

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G4HadronElastic::~G4HadronElastic ( )

virtual

Definition at line 63 of file G4HadronElastic.cc.

{}

Member Function Documentation

G4HadFinalState * G4HadronElastic::ApplyYourself ( const G4HadProjectile &  aTrack, G4Nucleus &  targetNucleus  )

virtual

Implements G4HadronicInteraction.

Reimplemented in G4LEnp, G4LEHadronProtonElastic, and G4LEpp.

Definition at line 80 of file G4HadronElastic.cc.

{
  theParticleChange.Clear();

  const G4HadProjectile* aParticle = &aTrack;
  G4double ekin = aParticle->GetKineticEnergy();
  if(ekin <= lowestEnergyLimit) {
    theParticleChange.SetEnergyChange(ekin);
    theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
    return &theParticleChange;
  }

  G4int A = targetNucleus.GetA_asInt();
  G4int Z = targetNucleus.GetZ_asInt();

  G4double plab = aParticle->GetTotalMomentum();

  // Scattered particle referred to axis of incident particle
  const G4ParticleDefinition* theParticle = aParticle->GetDefinition();
  G4double m1 = theParticle->GetPDGMass();

  if (verboseLevel>1) {
    G4cout << "G4HadronElastic: " 
       << aParticle->GetDefinition()->GetParticleName() 
       << " Plab(GeV/c)= " << plab/GeV  
       << " Ekin(MeV) = " << ekin/MeV 
       << " scattered off Z= " << Z 
       << " A= " << A 
       << G4endl;
  }

  G4double mass2 = G4NucleiProperties::GetNuclearMass(A, Z);
  G4LorentzVector lv1 = aParticle->Get4Momentum();
  G4LorentzVector lv(0.0,0.0,0.0,mass2);   
  lv += lv1;

  G4ThreeVector bst = lv.boostVector();
  lv1.boost(-bst);

  G4ThreeVector p1 = lv1.vect();
  G4double momentumCMS = p1.mag();
  G4double tmax = 4.0*momentumCMS*momentumCMS;

  // Sampling in CM system
  G4double t    = SampleInvariantT(theParticle, plab, Z, A);
  G4double phi  = G4UniformRand()*CLHEP::twopi;
  G4double cost = 1. - 2.0*t/tmax;
  G4double sint;

  // problem in sampling
  if(cost > 1.0 || cost < -1.0) {
    //if(verboseLevel > 0) {
      G4cout << "G4HadronElastic WARNING (1 - cost)= " << 1 - cost
         << " after scattering of " 
         << aParticle->GetDefinition()->GetParticleName()
         << " p(GeV/c)= " << plab/GeV
         << " on an ion Z= " << Z << " A= " << A
         << G4endl;
      //}
    cost = 1.0;
    sint = 0.0;

    // normal situation
  } else  {
    sint = std::sqrt((1.0-cost)*(1.0+cost));
  }    
  if (verboseLevel>1) {
    G4cout << " t= " << t << " tmax(GeV^2)= " << tmax/(GeV*GeV) 
       << " Pcms(GeV)= " << momentumCMS/GeV << " cos(t)=" << cost 
       << " sin(t)=" << sint << G4endl;
  }
  G4ThreeVector v1(sint*std::cos(phi),sint*std::sin(phi),cost);
  v1 *= momentumCMS;
  G4LorentzVector nlv1(v1.x(),v1.y(),v1.z(),
               std::sqrt(momentumCMS*momentumCMS + m1*m1));

  nlv1.boost(bst); 

  G4double eFinal = nlv1.e() - m1;
  if (verboseLevel > 1) {
    G4cout <<" m= " << m1 << " Efin(MeV)= " << eFinal 
       << " Proj: 4-mom " << lv1 << " Final: " << nlv1 
       << G4endl;
  }
  if(eFinal <= lowestEnergyLimit) {
    if(eFinal < 0.0 && verboseLevel > 0) {
      G4cout << "G4HadronElastic WARNING Efinal= " << eFinal
         << " after scattering of " 
         << aParticle->GetDefinition()->GetParticleName()
         << " p(GeV/c)= " << plab/GeV
         << " on an ion Z= " << Z << " A= " << A
         << G4endl;
    }
    theParticleChange.SetEnergyChange(0.0);
    nlv1 = G4LorentzVector(0.0,0.0,0.0,m1);

  } else {
    theParticleChange.SetMomentumChange(nlv1.vect().unit());
    theParticleChange.SetEnergyChange(eFinal);
  }  

  lv -= nlv1;
  G4double erec =  lv.e() - mass2;
  if (verboseLevel > 1) {
    G4cout << "Recoil: " <<" m= " << mass2 << " Erec(MeV)= " << erec
       << " 4-mom: " << lv 
       << G4endl;
  }
 
  if(erec > GetRecoilEnergyThreshold()) {
    G4ParticleDefinition * theDef = 0;
    if(Z == 1 && A == 1)       { theDef = theProton; }
    else if (Z == 1 && A == 2) { theDef = theDeuteron; }
    else if (Z == 1 && A == 3) { theDef = G4Triton::Triton(); }
    else if (Z == 2 && A == 3) { theDef = G4He3::He3(); }
    else if (Z == 2 && A == 4) { theDef = theAlpha; }
    else {
      theDef = 
    G4ParticleTable::GetParticleTable()->GetIonTable()->GetIon(Z,A,0.0);
    }
    G4DynamicParticle * aSec = new G4DynamicParticle(theDef, lv);
    theParticleChange.AddSecondary(aSec);
  } else if(erec > 0.0) {
    theParticleChange.SetLocalEnergyDeposit(erec);
  }

  return &theParticleChange;
}

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G4double G4HadronElastic::ComputeMomentumCMS ( const G4ParticleDefinition *  p, G4double  plab, G4int  Z, G4int  A  )

inline

Definition at line 98 of file G4HadronElastic.hh.

{
  G4double m1 = p->GetPDGMass();
  G4double m12= m1*m1;
  G4double mass2 = G4NucleiProperties::GetNuclearMass(A, Z);
  return plab*mass2/std::sqrt(m12 + mass2*mass2 + 2.*mass2*std::sqrt(m12 + plab*plab));
}

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G4double G4HadronElastic::LowestEnergyLimit ( ) const

inline

Definition at line 92 of file G4HadronElastic.hh.

{
  return lowestEnergyLimit;
}

void G4HadronElastic::ModelDescription ( std::ostream &  outFile ) const

virtual

Reimplemented from G4HadronicInteraction.

Reimplemented in G4ElasticHadrNucleusHE, and G4ChipsElasticModel.

Definition at line 67 of file G4HadronElastic.cc.

{

    outFile << "G4HadronElastic is a hadron-nucleus elastic scattering\n"
            << "model which uses the Gheisha two-exponential momentum\n"
            << "transfer parameterization.  The model is fully relativistic\n"
            << "as opposed to the original Gheisha model which was not.\n"
            << "This model may be used for all long-lived hadrons at all\n"
            << "incident energies.\n";

}

G4double G4HadronElastic::SampleInvariantT ( const G4ParticleDefinition *  p, G4double  plab, G4int  Z, G4int  A  )

virtual

Reimplemented from G4HadronicInteraction.

Reimplemented in G4ElasticHadrNucleusHE, G4hhElastic, G4DiffuseElastic, G4NuclNuclDiffuseElastic, G4LEnp, G4LEHadronProtonElastic, G4LEpp, G4ChipsElasticModel, and G4AntiNuclElastic.

Definition at line 212 of file G4HadronElastic.cc.

{
  static const G4double GeV2 = GeV*GeV;
  G4double momentumCMS = ComputeMomentumCMS(p,plab,Z,A);
  G4double tmax = 4.0*momentumCMS*momentumCMS/GeV2;
  G4double aa, bb, cc;
  G4double dd = 10.;
  G4Pow* g4pow = G4Pow::GetInstance();
  if (A <= 62) {
    bb = 14.5*g4pow->Z23(A);
    aa = g4pow->powZ(A, 1.63)/bb;
    cc = 1.4*g4pow->Z13(A)/dd;
  } else {
    bb = 60.*g4pow->Z13(A);
    aa = g4pow->powZ(A, 1.33)/bb;
    cc = 0.4*g4pow->powZ(A, 0.4)/dd;
  }
  G4double q1 = 1.0 - G4Exp(-bb*tmax);
  G4double q2 = 1.0 - G4Exp(-dd*tmax);
  G4double s1 = q1*aa;
  G4double s2 = q2*cc;
  if((s1 + s2)*G4UniformRand() < s2) {
    q1 = q2;
    bb = dd;
  }
  return -GeV2*G4Log(1.0 - G4UniformRand()*q1)/bb;
}

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void G4HadronElastic::SetLowestEnergyLimit ( G4double  value )

inline

Definition at line 87 of file G4HadronElastic.hh.

{
  lowestEnergyLimit = value;
}

---

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

• geant4.10.03.p01/source/processes/hadronic/models/coherent_elastic/include/G4HadronElastic.hh
• geant4.10.03.p01/source/processes/hadronic/models/coherent_elastic/src/G4HadronElastic.cc