#include <G4AnnihiToMuPair.hh>

Inheritance diagram for G4AnnihiToMuPair:

Public Member Functions
	G4AnnihiToMuPair (const G4String &processName="AnnihiToMuPair", G4ProcessType type=fElectromagnetic)

	~G4AnnihiToMuPair ()

G4bool	IsApplicable (const G4ParticleDefinition &) override

void	BuildPhysicsTable (const G4ParticleDefinition &) override

void	PrintInfoDefinition ()

void	SetCrossSecFactor (G4double fac)

G4double	GetCrossSecFactor ()

G4double	CrossSectionPerVolume (G4double PositronEnergy, const G4Material *)

G4double	ComputeCrossSectionPerAtom (G4double PositronEnergy, G4double AtomicZ)

G4double	GetMeanFreePath (const G4Track &aTrack, G4double previousStepSize, G4ForceCondition *) override

G4VParticleChange *	PostStepDoIt (const G4Track &aTrack, const G4Step &aStep) override

Public Member Functions inherited from G4VDiscreteProcess
	G4VDiscreteProcess (const G4String &aName, G4ProcessType aType=fNotDefined)

	G4VDiscreteProcess (G4VDiscreteProcess &)

virtual	~G4VDiscreteProcess ()

G4VDiscreteProcess &	operator= (const G4VDiscreteProcess &)=delete

virtual G4double	PostStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)

virtual G4VParticleChange *	PostStepDoIt (const G4Track &, const G4Step &)

virtual G4double	AlongStepGetPhysicalInteractionLength (const G4Track &, G4double, G4double, G4double &, G4GPILSelection *)

virtual G4double	AtRestGetPhysicalInteractionLength (const G4Track &, G4ForceCondition *)

virtual G4VParticleChange *	AtRestDoIt (const G4Track &, const G4Step &)

virtual G4VParticleChange *	AlongStepDoIt (const G4Track &, const G4Step &)

Public Member Functions inherited from G4VProcess
	G4VProcess (const G4String &aName="NoName", G4ProcessType aType=fNotDefined)

	G4VProcess (const G4VProcess &right)

virtual	~G4VProcess ()

G4VProcess &	operator= (const G4VProcess &)=delete

G4bool	operator== (const G4VProcess &right) const

G4bool	operator!= (const G4VProcess &right) const

virtual G4VParticleChange *	PostStepDoIt (const G4Track &track, const G4Step &stepData)=0

virtual G4VParticleChange *	AlongStepDoIt (const G4Track &track, const G4Step &stepData)=0

virtual G4VParticleChange *	AtRestDoIt (const G4Track &track, const G4Step &stepData)=0

virtual G4double	AlongStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4double currentMinimumStep, G4double &proposedSafety, G4GPILSelection *selection)=0

virtual G4double	AtRestGetPhysicalInteractionLength (const G4Track &track, G4ForceCondition *condition)=0

virtual G4double	PostStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)=0

G4double	GetCurrentInteractionLength () const

void	SetPILfactor (G4double value)

G4double	GetPILfactor () const

G4double	AlongStepGPIL (const G4Track &track, G4double previousStepSize, G4double currentMinimumStep, G4double &proposedSafety, G4GPILSelection *selection)

G4double	AtRestGPIL (const G4Track &track, G4ForceCondition *condition)

G4double	PostStepGPIL (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)

virtual G4bool	IsApplicable (const G4ParticleDefinition &)

virtual void	BuildPhysicsTable (const G4ParticleDefinition &)

virtual void	PreparePhysicsTable (const G4ParticleDefinition &)

virtual G4bool	StorePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)

virtual G4bool	RetrievePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)

const G4String &	GetPhysicsTableFileName (const G4ParticleDefinition *, const G4String &directory, const G4String &tableName, G4bool ascii=false)

const G4String &	GetProcessName () const

G4ProcessType	GetProcessType () const

void	SetProcessType (G4ProcessType)

G4int	GetProcessSubType () const

void	SetProcessSubType (G4int)

virtual void	StartTracking (G4Track *)

virtual void	EndTracking ()

virtual void	SetProcessManager (const G4ProcessManager *)

virtual const G4ProcessManager *	GetProcessManager ()

virtual void	ResetNumberOfInteractionLengthLeft ()

G4double	GetNumberOfInteractionLengthLeft () const

G4double	GetTotalNumberOfInteractionLengthTraversed () const

G4bool	isAtRestDoItIsEnabled () const

G4bool	isAlongStepDoItIsEnabled () const

G4bool	isPostStepDoItIsEnabled () const

virtual void	DumpInfo () const

virtual void	ProcessDescription (std::ostream &outfile) const

void	SetVerboseLevel (G4int value)

G4int	GetVerboseLevel () const

virtual void	SetMasterProcess (G4VProcess *masterP)

const G4VProcess *	GetMasterProcess () const

virtual void	BuildWorkerPhysicsTable (const G4ParticleDefinition &part)

virtual void	PrepareWorkerPhysicsTable (const G4ParticleDefinition &)

Additional Inherited Members
Static Public Member Functions inherited from G4VProcess
static const G4String &	GetProcessTypeName (G4ProcessType)

virtual G4double	GetMeanFreePath (const G4Track &aTrack, G4double previousStepSize, G4ForceCondition *condition)=0

Protected Member Functions inherited from G4VProcess
void	SubtractNumberOfInteractionLengthLeft (G4double prevStepSize)

void	ClearNumberOfInteractionLengthLeft ()

Protected Attributes inherited from G4VProcess
const G4ProcessManager *	aProcessManager = nullptr

G4VParticleChange *	pParticleChange = nullptr

G4ParticleChange	aParticleChange

G4double	theNumberOfInteractionLengthLeft = -1.0

G4double	currentInteractionLength = -1.0

G4double	theInitialNumberOfInteractionLength = -1.0

G4String	theProcessName

G4String	thePhysicsTableFileName

G4ProcessType	theProcessType = fNotDefined

G4int	theProcessSubType = -1

G4double	thePILfactor = 1.0

G4int	verboseLevel = 0

G4bool	enableAtRestDoIt = true

G4bool	enableAlongStepDoIt = true

G4bool	enablePostStepDoIt = true

Detailed Description

Definition at line 56 of file G4AnnihiToMuPair.hh.

Constructor & Destructor Documentation

◆ G4AnnihiToMuPair()

G4AnnihiToMuPair::G4AnnihiToMuPair	(	const G4String &	processName = `"AnnihiToMuPair"`,
		G4ProcessType	type = `fElectromagnetic`
	)

explicit

Definition at line 59 of file G4AnnihiToMuPair.cc.

                       :G4VDiscreteProcess (processName, type)
{
  //e+ Energy threshold
  const G4double Mu_massc2 = G4MuonPlus::MuonPlus()->GetPDGMass();
  LowestEnergyLimit = 2.*Mu_massc2*Mu_massc2/electron_mass_c2 - electron_mass_c2;
 
  //modele ok up to 1000 TeV due to neglected Z-interference
  HighestEnergyLimit = 1000.*TeV;
 
  CurrentSigma = 0.0;
  CrossSecFactor = 1.;
  SetProcessSubType(6);
  G4LossTableManager::Instance()->Register(this);
}

◆ ~G4AnnihiToMuPair()

G4AnnihiToMuPair::~G4AnnihiToMuPair ( )

Definition at line 77 of file G4AnnihiToMuPair.cc.

{ 
  G4LossTableManager::Instance()->DeRegister(this);
}

Member Function Documentation

◆ BuildPhysicsTable()

void G4AnnihiToMuPair::BuildPhysicsTable ( const G4ParticleDefinition & )

overridevirtual

Reimplemented from G4VProcess.

Definition at line 91 of file G4AnnihiToMuPair.cc.

{
  CurrentSigma = 0.0;
  PrintInfoDefinition();
}

◆ ComputeCrossSectionPerAtom()

G4double G4AnnihiToMuPair::ComputeCrossSectionPerAtom	(	G4double	PositronEnergy,
		G4double	AtomicZ
	)

Definition at line 111 of file G4AnnihiToMuPair.cc.

{
  static const G4double Mmuon = G4MuonPlus::MuonPlus()->GetPDGMass();
  static const G4double Rmuon = CLHEP::elm_coupling/Mmuon; //classical particle radius
  static const G4double Sig0  = CLHEP::pi*Rmuon*Rmuon/3.;  //constant in crossSection
  static const G4double pia = CLHEP::pi * CLHEP::fine_structure_const; // pi * alphaQED
 
  G4double CrossSection = 0.;
  if (Epos < LowestEnergyLimit) return CrossSection;
   
  G4double xi = LowestEnergyLimit/Epos;
  G4double piaxi = pia * sqrt(xi);
  G4double SigmaEl = Sig0 * xi * (1.+xi/2.) * piaxi;
  if( Epos>LowestEnergyLimit+1.e-5 ) SigmaEl /= (1.-std::exp( -piaxi/std::sqrt(1-xi) ));
  CrossSection = SigmaEl*Z; // SigmaEl per electron * number of electrons per atom
  return CrossSection;
}

Referenced by CrossSectionPerVolume().

◆ CrossSectionPerVolume()

G4double G4AnnihiToMuPair::CrossSectionPerVolume	(	G4double	PositronEnergy,
		const G4Material *	aMaterial
	)

Definition at line 133 of file G4AnnihiToMuPair.cc.

{
  const G4ElementVector* theElementVector = aMaterial->GetElementVector();
  const G4double* NbOfAtomsPerVolume = aMaterial->GetVecNbOfAtomsPerVolume();
 
  G4double SIGMA = 0.0;
 
  for ( size_t i=0 ; i < aMaterial->GetNumberOfElements() ; ++i )
  {
    G4double AtomicZ = (*theElementVector)[i]->GetZ();
    SIGMA += NbOfAtomsPerVolume[i] *
      ComputeCrossSectionPerAtom(PositronEnergy,AtomicZ);
  }
  return SIGMA;
}

Referenced by GetMeanFreePath(), and PostStepDoIt().

◆ GetCrossSecFactor()

G4double G4AnnihiToMuPair::GetCrossSecFactor ( )

inline

Definition at line 80 of file G4AnnihiToMuPair.hh.

80{return CrossSecFactor;};

◆ GetMeanFreePath()

G4double G4AnnihiToMuPair::GetMeanFreePath	(	const G4Track &	aTrack,
		G4double	previousStepSize,
		G4ForceCondition *
	)

overridevirtual

Implements G4VDiscreteProcess.

Definition at line 152 of file G4AnnihiToMuPair.cc.

{
  const G4DynamicParticle* aDynamicPositron = aTrack.GetDynamicParticle();
  G4double PositronEnergy = aDynamicPositron->GetKineticEnergy()
                                              +electron_mass_c2;
  G4Material* aMaterial = aTrack.GetMaterial();
  CurrentSigma = CrossSectionPerVolume(PositronEnergy, aMaterial);
 
  // increase the CrossSection by CrossSecFactor (default 1)
  G4double mfp = DBL_MAX;
  if(CurrentSigma > DBL_MIN) mfp = 1.0/(CurrentSigma*CrossSecFactor);
 
  return mfp;
}

◆ IsApplicable()

G4bool G4AnnihiToMuPair::IsApplicable ( const G4ParticleDefinition & particle )

overridevirtual

Reimplemented from G4VProcess.

Definition at line 84 of file G4AnnihiToMuPair.cc.

{
  return ( &particle == G4Positron::Positron() );
}

◆ PostStepDoIt()

G4VParticleChange * G4AnnihiToMuPair::PostStepDoIt	(	const G4Track &	aTrack,
		const G4Step &	aStep
	)

overridevirtual

Reimplemented from G4VDiscreteProcess.

Definition at line 173 of file G4AnnihiToMuPair.cc.

{
 
  aParticleChange.Initialize(aTrack);
  static const G4double Mele=electron_mass_c2;
  static const G4double Mmuon=G4MuonPlus::MuonPlus()->GetPDGMass();
 
  // current Positron energy and direction, return if energy too low
  const G4DynamicParticle *aDynamicPositron = aTrack.GetDynamicParticle();
  G4double Epos = aDynamicPositron->GetKineticEnergy() + Mele; 
 
  // test of cross section
  if(CurrentSigma*G4UniformRand() > 
     CrossSectionPerVolume(Epos, aTrack.GetMaterial())) 
    {
      return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
    }
 
  if (Epos < LowestEnergyLimit) {
     return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
  }
 
  G4ParticleMomentum PositronDirection = 
                                       aDynamicPositron->GetMomentumDirection();
  G4double xi = LowestEnergyLimit/Epos; // xi is always less than 1,
                                        // goes to 0 at high Epos
 
  // generate cost
  //
  G4double cost;
  do { cost = 2.*G4UniformRand()-1.; }
  // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
  while (2.*G4UniformRand() > 1.+xi+cost*cost*(1.-xi) ); 
                                                       //1+cost**2 at high Epos
  G4double sint = sqrt(1.-cost*cost);
 
  // generate phi
  //
  G4double phi=2.*pi*G4UniformRand();
 
  G4double Ecm   = sqrt(0.5*Mele*(Epos+Mele));
  G4double Pcm   = sqrt(Ecm*Ecm-Mmuon*Mmuon);
  G4double beta  = sqrt((Epos-Mele)/(Epos+Mele));
  G4double gamma = Ecm/Mele;                    // =sqrt((Epos+Mele)/(2.*Mele));
  G4double Pt    = Pcm*sint;
  
  // energy and momentum of the muons in the Lab
  //
  G4double EmuPlus   = gamma*(     Ecm+cost*beta*Pcm);
  G4double EmuMinus  = gamma*(     Ecm-cost*beta*Pcm);
  G4double PmuPlusZ  = gamma*(beta*Ecm+cost*     Pcm);
  G4double PmuMinusZ = gamma*(beta*Ecm-cost*     Pcm);
  G4double PmuPlusX  = Pt*cos(phi);
  G4double PmuPlusY  = Pt*sin(phi);
  G4double PmuMinusX =-Pt*cos(phi);
  G4double PmuMinusY =-Pt*sin(phi);
  // absolute momenta
  G4double PmuPlus  = sqrt(Pt*Pt+PmuPlusZ *PmuPlusZ );
  G4double PmuMinus = sqrt(Pt*Pt+PmuMinusZ*PmuMinusZ);
 
  // mu+ mu- directions for Positron in z-direction
  //
  G4ThreeVector
    MuPlusDirection ( PmuPlusX/PmuPlus, PmuPlusY/PmuPlus,  PmuPlusZ/PmuPlus  );
  G4ThreeVector
    MuMinusDirection(PmuMinusX/PmuMinus,PmuMinusY/PmuMinus,PmuMinusZ/PmuMinus);
 
  // rotate to actual Positron direction
  //
  MuPlusDirection.rotateUz(PositronDirection);
  MuMinusDirection.rotateUz(PositronDirection);
 
  aParticleChange.SetNumberOfSecondaries(2);
  // create G4DynamicParticle object for the particle1
  G4DynamicParticle* aParticle1= new G4DynamicParticle(
                         G4MuonPlus::MuonPlus(),MuPlusDirection,EmuPlus-Mmuon);
  aParticleChange.AddSecondary(aParticle1);
  // create G4DynamicParticle object for the particle2
  G4DynamicParticle* aParticle2= new G4DynamicParticle(
                     G4MuonMinus::MuonMinus(),MuMinusDirection,EmuMinus-Mmuon);
  aParticleChange.AddSecondary(aParticle2);
 
  // Kill the incident positron 
  //
  aParticleChange.ProposeEnergy(0.); 
  aParticleChange.ProposeTrackStatus(fStopAndKill);
 
  return &aParticleChange;
}

◆ PrintInfoDefinition()

void G4AnnihiToMuPair::PrintInfoDefinition ( )

Definition at line 269 of file G4AnnihiToMuPair.cc.

{
  G4String comments ="e+e->mu+mu- annihilation, atomic e- at rest, SubType=.";
  G4cout << G4endl << GetProcessName() << ":  " << comments 
     << GetProcessSubType() << G4endl;
  G4cout << "        threshold at " << LowestEnergyLimit/GeV << " GeV"
         << " good description up to "
         << HighestEnergyLimit/TeV << " TeV for all Z." << G4endl;
}

Referenced by BuildPhysicsTable().

◆ SetCrossSecFactor()

void G4AnnihiToMuPair::SetCrossSecFactor ( G4double fac )

Definition at line 101 of file G4AnnihiToMuPair.cc.

{ 
  CrossSecFactor = fac;
  G4cout << "The cross section for AnnihiToMuPair is artificially "
         << "increased by the CrossSecFactor=" << CrossSecFactor << G4endl;
}

Referenced by G4EmExtraPhysics::ConstructProcess().

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ G4AnnihiToMuPair()

◆ ~G4AnnihiToMuPair()

Member Function Documentation

◆ BuildPhysicsTable()

◆ ComputeCrossSectionPerAtom()

◆ CrossSectionPerVolume()

◆ GetCrossSecFactor()

◆ GetMeanFreePath()

◆ IsApplicable()

◆ PostStepDoIt()

◆ PrintInfoDefinition()

◆ SetCrossSecFactor()