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geant4/source/processes/electromagnetic/dna/models/src/G4DNABornAngle.cc
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//
// ********************************************************************
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// * *
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//
// -------------------------------------------------------------------
//
// GEANT4 Class file
//
//
// File name: G4DNABornAngle
//
// Author: Vladimir Ivantcheko
//
// Creation date: 23 August 2013
//
// Modifications:
//
// Class Description:
//
// Delta-electron Angular Distribution Generation
//
// Class Description: End
//
// -------------------------------------------------------------------
//
#include "G4DNABornAngle.hh"
#include "G4PhysicalConstants.hh"
#include "Randomize.hh"
#include "G4ParticleDefinition.hh"
#include "G4Electron.hh"
#include "G4SystemOfUnits.hh"
using namespace std;
G4DNABornAngle::G4DNABornAngle(const G4String&)
: G4VEmAngularDistribution("deltaBorn")
{
fElectron = G4Electron::Electron();
}
G4DNABornAngle::~G4DNABornAngle()
{}
G4ThreeVector&
G4DNABornAngle::SampleDirectionForShell(const G4DynamicParticle* dp,
G4double secKinetic, G4int,
G4int,
const G4Material*)
{
G4double k = dp->GetKineticEnergy();
G4double cosTheta = 1.0;
if (dp->GetDefinition() == fElectron)
{
if (secKinetic < 50.*eV) cosTheta = (2.*G4UniformRand())-1.;
else if (secKinetic <= 200.*eV)
{
if (G4UniformRand() <= 0.1) cosTheta = (2.*G4UniformRand())-1.;
else cosTheta = G4UniformRand()*(std::sqrt(2.)/2);
}
else
{
G4double sin2O =
(1.-secKinetic/k)/(1.+secKinetic/(2.*electron_mass_c2));
cosTheta = std::sqrt(1.-sin2O);
}
}
else
{
G4double mass = dp->GetDefinition()->GetPDGMass();
G4double maxSecKinetic = 4.* (electron_mass_c2 / mass) * k;
// cosTheta = std::sqrt(secKinetic / maxSecKinetic);
// Restriction below 100 eV from Emfietzoglou (2000)
if (secKinetic>100*eV) cosTheta = std::sqrt(secKinetic / maxSecKinetic);
else cosTheta = (2.*G4UniformRand())-1.;
}
G4double sint = sqrt((1.0 - cosTheta)*(1.0 + cosTheta));
G4double phi = twopi*G4UniformRand();
fLocalDirection.set(sint*cos(phi), sint*sin(phi), cosTheta);
fLocalDirection.rotateUz(dp->GetMomentumDirection());
return fLocalDirection;
}
G4ThreeVector&
G4DNABornAngle::SampleDirection(const G4DynamicParticle* dp,
G4double secEkin, G4int Z,
const G4Material* mat)
{
return SampleDirectionForShell(dp, secEkin, Z, 0, mat);
}
void G4DNABornAngle::PrintGeneratorInformation() const
{}