G4RDGenerator2BS Class Reference

#include <G4RDGenerator2BS.hh>

Inheritance diagram for G4RDGenerator2BS:

Public Member Functions
	G4RDGenerator2BS (const G4String &name)
	~G4RDGenerator2BS ()
G4double	PolarAngle (const G4double initial_energy, const G4double final_energy, const G4int Z)
void	PrintGeneratorInformation () const
Public Member Functions inherited from G4RDVBremAngularDistribution
	G4RDVBremAngularDistribution (const G4String &name)
virtual	~G4RDVBremAngularDistribution ()

Protected Member Functions
G4double	RejectionFunction (G4double value) const

Detailed Description

Definition at line 59 of file G4RDGenerator2BS.hh.

Constructor & Destructor Documentation

G4RDGenerator2BS::G4RDGenerator2BS

(

const G4String &

name

)

Definition at line 60 of file G4RDGenerator2BS.cc.

                                                      :G4RDVBremAngularDistribution(name)
{;}

G4RDGenerator2BS::~G4RDGenerator2BS

(

)

Definition at line 65 of file G4RDGenerator2BS.cc.

{;}

Member Function Documentation

G4double G4RDGenerator2BS::PolarAngle ( const G4double  initial_energy, const G4double  final_energy, const G4int  Z  )

virtual

Implements G4RDVBremAngularDistribution.

Definition at line 70 of file G4RDGenerator2BS.cc.

References python.hepunit::electron_mass_c2, G4UniformRand, G4INCL::Math::max(), python.hepunit::pi, and RejectionFunction().

{

  // 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 theta = 0;

  G4double initialTotalEnergy = (initial_energy+electron_mass_c2)/electron_mass_c2;
  G4double finalTotalEnergy = (final_energy+electron_mass_c2)/electron_mass_c2;
  EnergyRatio = finalTotalEnergy/initialTotalEnergy;
  G4double gMaxEnergy = (pi*initialTotalEnergy)*(pi*initialTotalEnergy);

  G4double Zeff = std::sqrt(static_cast<G4double>(Z) * (static_cast<G4double>(Z) + 1.0));
  z = (0.00008116224*(std::pow(Zeff,0.3333333)));

  // Rejection arguments
  rejection_argument1 = (1.0+EnergyRatio*EnergyRatio); 
  rejection_argument2 = - 2.0*EnergyRatio + 3.0*rejection_argument1;
  rejection_argument3 = ((1-EnergyRatio)/(2.0*initialTotalEnergy*EnergyRatio))*
    ((1-EnergyRatio)/(2.0*initialTotalEnergy*EnergyRatio));

  // Calculate rejection function at 0, 1 and Emax
  G4double gfunction0 = RejectionFunction(0);
  G4double gfunction1 = RejectionFunction(1);
  G4double gfunctionEmax = RejectionFunction(gMaxEnergy);


  // Calculate Maximum value 
  G4double gMaximum = std::max(gfunction0,gfunction1);
  gMaximum = std::max(gMaximum,gfunctionEmax);

  G4double rand, gfunctionTest, randTest;

  do{
    rand = G4UniformRand();
    rand = rand/(1-rand+1.0/gMaxEnergy);
    gfunctionTest = RejectionFunction(rand);
    randTest = G4UniformRand();

  }while(randTest > (gfunctionTest/gMaximum));

  theta = std::sqrt(rand)/initialTotalEnergy;


  return theta;
}

void G4RDGenerator2BS::PrintGeneratorInformation ( ) const

virtual

Implements G4RDVBremAngularDistribution.

Definition at line 138 of file G4RDGenerator2BS.cc.

References G4cout, and G4endl.

{
  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;
} 

G4double G4RDGenerator2BS::RejectionFunction ( G4double  value ) const

protected

Definition at line 126 of file G4RDGenerator2BS.cc.

Referenced by PolarAngle().

{

  G4double argument = (1+value)*(1+value);

  G4double gfunction = (4+std::log(rejection_argument3+(z/argument)))*
    ((4*EnergyRatio*value/argument)-rejection_argument1)+rejection_argument2;

  return gfunction;

}

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

• G4RDGenerator2BS.hh
• G4RDGenerator2BS.cc