G4Generator2BS Class Reference

#include <G4Generator2BS.hh>

Inheritance diagram for G4Generator2BS:

Public Member Functions
	G4Generator2BS (const G4String &name="")
virtual	~G4Generator2BS ()
G4ThreeVector &	SampleDirection (const G4DynamicParticle *dp, G4double out_energy, G4int Z, const G4Material *mat=nullptr) override
void	PrintGeneratorInformation () const override
G4Generator2BS &	operator= (const G4Generator2BS &right)=delete
	G4Generator2BS (const G4Generator2BS &)=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

Protected Member Functions
G4double	RejectionFunction (G4double value) const

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

Detailed Description

Definition at line 64 of file G4Generator2BS.hh.

Constructor & Destructor Documentation

G4Generator2BS() [1/2]

G4Generator2BS::G4Generator2BS ( const G4String & name = "" )

explicit

Definition at line 63 of file G4Generator2BS.cc.

  : G4VEmAngularDistribution("AngularGen2BS"),fz(1.),ratio(1.),
    ratio1(1.),ratio2(1.),delta(0.)
{
  g4pow = G4Pow::GetInstance();
  nwarn = 0;
}

Referenced by G4Generator2BS(), and operator=().

~G4Generator2BS()

G4Generator2BS::~G4Generator2BS ( )

virtual

Definition at line 71 of file G4Generator2BS.cc.

{}

G4Generator2BS() [2/2]

G4Generator2BS::G4Generator2BS ( const G4Generator2BS & )

delete

Member Function Documentation

operator=()

G4Generator2BS & G4Generator2BS::operator= ( const G4Generator2BS & right )

delete

PrintGeneratorInformation()

void G4Generator2BS::PrintGeneratorInformation ( ) const

overridevirtual

Reimplemented from G4VEmAngularDistribution.

Definition at line 134 of file G4Generator2BS.cc.

{
  G4cout << "\n" << G4endl;
  G4cout << "Bremsstrahlung Angular Generator is 2BS Generator "
     << "from 2BS Koch & Motz distribution (Rev Mod Phys 31(4), 920 (1959))" << G4endl;
  G4cout << "Sampling algorithm adapted from PIRS-0203" << G4endl;
  G4cout << "\n" << G4endl;
} 

RejectionFunction()

G4double G4Generator2BS::RejectionFunction ( G4double value ) const

inlineprotected

Definition at line 99 of file G4Generator2BS.hh.

{
  G4double y2 = (1 + y)*(1 + y);
  G4double x  = 4*y*ratio/y2;
  return 4*x - ratio1 - (ratio2 - x)*G4Log(delta + fz/y2); 
}

Referenced by SampleDirection().

SampleDirection()

G4ThreeVector & G4Generator2BS::SampleDirection ( const G4DynamicParticle * dp, G4double out_energy, G4int Z, const G4Material * mat = nullptr )

overridevirtual

Implements G4VEmAngularDistribution.

Definition at line 74 of file G4Generator2BS.cc.

{
  // Adapted from "Improved bremsstrahlung photon angular sampling in the EGS4 code system"
  // by Alex F. Bielajew, Rahde Mohan anc Chen-Shou Chui, PIRS-0203
  // Ionizing Radiation Standards
  // Institute for National Measurement Standards 
  // National Research Council of Canada
  // Departement of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York
 
  G4double energy = dp->GetTotalEnergy();
  ratio = final_energy/energy;
  ratio1 = (1 + ratio)*(1 + ratio);
  ratio2 = 1 + ratio*ratio;
 
  G4double gamma = energy/electron_mass_c2;
  G4double beta  = std::sqrt((gamma - 1)*(gamma + 1))/gamma;
 
  // VI speadup
  fz = 0.00008116224*g4pow->Z13(Z)*g4pow->Z13(Z+1);
 
  // majoranta
  G4double ymax = 2*beta*(1 + beta)*gamma*gamma;
  G4double gMax = RejectionFunction(0.0);
  gMax = std::max(gMax,RejectionFunction(ymax));
 
  G4double y, gfun;
 
  do{
    G4double q = G4UniformRand();
    y = q*ymax/(1 + ymax*(1 - q));
    gfun = RejectionFunction(y);
 
    // violation point
    if(gfun > gMax && nwarn >= 20) {
      ++nwarn;
      G4cout << "### WARNING in G4Generator2BS: Etot(MeV)= " << energy/MeV 
         << "  Egamma(MeV)" << (energy - final_energy)/MeV
         << " gMax= " << gMax << "  < " << gfun
         << "  results are not reliable!" 
         << G4endl;
      if(20 == nwarn) { 
    G4cout << "   WARNING in G4Generator2BS is closed" << G4endl; 
      }
    }
 
  } while(G4UniformRand()*gMax > gfun || y > ymax);
  
  G4double cost = 1 - 2*y/ymax;
  G4double sint = std::sqrt((1 - cost)*(1 + cost));
  G4double phi  = 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:

• G4Generator2BS.hh
• G4Generator2BS.cc