G4SauterGavrilaAngularDistribution Class Reference

#include <G4SauterGavrilaAngularDistribution.hh>

Inheritance diagram for G4SauterGavrilaAngularDistribution:

Public Member Functions
	G4SauterGavrilaAngularDistribution ()
	~G4SauterGavrilaAngularDistribution () override
G4ThreeVector &	SampleDirection (const G4DynamicParticle *dp, G4double e=0.0, G4int shellId=0, const G4Material *mat=nullptr) final
void	PrintGeneratorInformation () const override
G4SauterGavrilaAngularDistribution &	operator= (const G4SauterGavrilaAngularDistribution &right)=delete
	G4SauterGavrilaAngularDistribution (const G4SauterGavrilaAngularDistribution &)=delete
Public Member Functions inherited from G4VEmAngularDistribution
	G4VEmAngularDistribution (const G4String &name)
virtual	~G4VEmAngularDistribution ()
virtual G4ThreeVector &	SampleDirectionForShell (const G4DynamicParticle *dp, G4double finalTotalEnergy, G4int Z, G4int shellID, const G4Material *)
virtual void	SamplePairDirections (const G4DynamicParticle *dp, G4double elecKinEnergy, G4double posiKinEnergy, G4ThreeVector &dirElectron, G4ThreeVector &dirPositron, G4int Z=0, const G4Material *mat=nullptr)
const G4String &	GetName () const
G4VEmAngularDistribution &	operator= (const G4VEmAngularDistribution &right)=delete
	G4VEmAngularDistribution (const G4VEmAngularDistribution &)=delete

Additional Inherited Members
Protected Attributes inherited from G4VEmAngularDistribution
G4ThreeVector	fLocalDirection
G4bool	fPolarisation

Detailed Description

Definition at line 52 of file G4SauterGavrilaAngularDistribution.hh.

Constructor & Destructor Documentation

G4SauterGavrilaAngularDistribution() [1/2]

G4SauterGavrilaAngularDistribution::G4SauterGavrilaAngularDistribution ( )

explicit

Definition at line 48 of file G4SauterGavrilaAngularDistribution.cc.

  : G4VEmAngularDistribution("SauterGavrila")
{}    

~G4SauterGavrilaAngularDistribution()

G4SauterGavrilaAngularDistribution::~G4SauterGavrilaAngularDistribution ( )

overridedefault

G4SauterGavrilaAngularDistribution() [2/2]

G4SauterGavrilaAngularDistribution::G4SauterGavrilaAngularDistribution ( const G4SauterGavrilaAngularDistribution & )

delete

Member Function Documentation

operator=()

G4SauterGavrilaAngularDistribution & G4SauterGavrilaAngularDistribution::operator= ( const G4SauterGavrilaAngularDistribution & right )

delete

PrintGeneratorInformation()

void G4SauterGavrilaAngularDistribution::PrintGeneratorInformation ( ) const

overridevirtual

Reimplemented from G4VEmAngularDistribution.

Definition at line 110 of file G4SauterGavrilaAngularDistribution.cc.

{
  G4cout << "\n" << G4endl;
  G4cout << "Non-polarized photoelectric effect angular generator." << G4endl;
  G4cout << "The Sauter-Gavrila distribution for the K-shell is used."<<G4endl;
  G4cout << "Originally developed by M.Maire for Geant3" 
         << G4endl;
} 

SampleDirection()

G4ThreeVector & G4SauterGavrilaAngularDistribution::SampleDirection ( const G4DynamicParticle * dp, G4double e = 0.0, G4int shellId = 0, const G4Material * mat = nullptr )

finalvirtual

Implements G4VEmAngularDistribution.

Definition at line 55 of file G4SauterGavrilaAngularDistribution.cc.

{
  static const G4double emin = 1*CLHEP::eV;
  static const G4double emax = 100*CLHEP::MeV;
 
  G4double energy = std::max(dp->GetKineticEnergy(), emin);
  if (energy > emax) {
    fLocalDirection = dp->GetMomentumDirection();
  } else {
    // Initial algorithm according Penelope 2008 manual and 
    // F.Sauter Ann. Physik 9, 217(1931); 11, 454(1931).
    // Modified according Penelope 2014 manual 
    G4double costheta = 0.0;
 
    // 1) initialize energy-dependent variables
    // Variable naming according to Eq. (2.24) of Penelope Manual
    // (pag. 44)
    G4double tau = energy/electron_mass_c2;
    G4double gamma = 1.0 + tau;
    G4double beta = std::sqrt(tau*(tau + 2.0))/gamma;
    
    // ac corresponds to "A" of Eq. (2.31)
    //
    G4double ac = (1.0 - beta)/beta;
    G4double a1 = 0.5*beta*gamma*tau*(gamma-2.0);
    G4double a2 = ac + 2.0;
    // gtmax = maximum of the rejection function according to Eq. (2.28), 
    // obtained for tsam=0
    G4double gtmax = 2.0*(a1 + 1.0/ac);
    
    G4double tsam = 0.0;
    G4double gtr  = 0.0;
    
    //2) sampling. Eq. (2.31) of Penelope Manual
    // tsam = 1-std::cos(theta)
    // gtr = rejection function according to Eq. (2.28)
    do{
      G4double rand = G4UniformRand();
      tsam = 2.0*ac * (2.0*rand + a2*std::sqrt(rand)) / (a2*a2 - 4.0*rand);
      gtr = (2.0 - tsam) * (a1 + 1.0/(ac+tsam));
      // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
    } while(G4UniformRand()*gtmax > gtr);
 
    costheta = 1.0 - tsam;
        
    G4double sint = std::sqrt(tsam*(2.0 - tsam));
    G4double phi  = CLHEP::twopi*G4UniformRand();
        
    fLocalDirection.set(sint*std::cos(phi), sint*std::sin(phi), costheta);
    fLocalDirection.rotateUz(dp->GetMomentumDirection());
  }
  return fLocalDirection;
}

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

• G4SauterGavrilaAngularDistribution.hh
• G4SauterGavrilaAngularDistribution.cc