G4ModifiedTsai Class Reference

#include <G4ModifiedTsai.hh>

Inheritance diagram for G4ModifiedTsai:

Public Member Functions
	G4ModifiedTsai (const G4String &name="")
virtual	~G4ModifiedTsai ()
virtual G4ThreeVector &	SampleDirection (const G4DynamicParticle *dp, G4double out_energy, G4int Z, const G4Material *mat=0)
void	PrintGeneratorInformation () const
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 *)
const G4String &	GetName () const

Additional Inherited Members
Protected Attributes inherited from G4VEmAngularDistribution
G4ThreeVector	fLocalDirection

Detailed Description

Definition at line 63 of file G4ModifiedTsai.hh.

Constructor & Destructor Documentation

G4ModifiedTsai::G4ModifiedTsai

(

const G4String &

name = ""

)

Definition at line 64 of file G4ModifiedTsai.cc.

  : G4VEmAngularDistribution("AngularGenUrban")
{}    

G4ModifiedTsai::~G4ModifiedTsai ( )

virtual

Definition at line 68 of file G4ModifiedTsai.cc.

{}

Member Function Documentation

void G4ModifiedTsai::PrintGeneratorInformation

(

)

const

Definition at line 104 of file G4ModifiedTsai.cc.

References G4cout, and G4endl.

{
  G4cout << "\n" << G4endl;
  G4cout << "Bremsstrahlung Angular Generator is Modified Tsai" << G4endl;
  G4cout << "Distribution suggested by L.Urban (Geant3 manual (1993) Phys211)" 
     << G4endl;
  G4cout << "Derived from Tsai distribution (Rev Mod Phys 49,421(1977)) \n" 
     << G4endl;
} 

G4ThreeVector & G4ModifiedTsai::SampleDirection ( const G4DynamicParticle *  dp, G4double  out_energy, G4int  Z, const G4Material *  mat = 0  )

virtual

Implements G4VEmAngularDistribution.

Definition at line 72 of file G4ModifiedTsai.cc.

References python.hepunit::electron_mass_c2, G4VEmAngularDistribution::fLocalDirection, G4Log(), G4UniformRand, G4DynamicParticle::GetKineticEnergy(), G4DynamicParticle::GetMomentumDirection(), CLHEP::Hep3Vector::rotateUz(), and CLHEP::Hep3Vector::set().

{
  // Sample gamma angle (Z - axis along the parent particle).
  // Universal distribution suggested by L. Urban (Geant3 manual (1993) 
  // Phys211) derived from Tsai distribution (Rev Mod Phys 49,421(1977))

  G4double uMax = 2*(1. + dp->GetKineticEnergy()/electron_mass_c2);   

  static const G4double a1     = 0.625;
  static const G4double a2     = 1.875;
  static const G4double border = 0.25;
  G4double u;

  do {
    u = - G4Log(G4UniformRand()*G4UniformRand());

    if ( border > G4UniformRand() ) { u /= a1; }
    else                            { u /= a2; }
    
  } while(u > uMax);

  G4double cost = 1.0 - 2*u*u/(uMax*uMax);
  G4double sint = std::sqrt((1 - cost)*(1 + cost));
  G4double phi  = CLHEP::twopi*G4UniformRand(); 

  fLocalDirection.set(sint*std::cos(phi), sint*std::sin(phi), cost);
  fLocalDirection.rotateUz(dp->GetMomentumDirection());

  return fLocalDirection;
}

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

• G4ModifiedTsai.hh
• G4ModifiedTsai.cc