G4PolarizedComptonCrossSection Class Reference

#include <G4PolarizedComptonCrossSection.hh>

Inheritance diagram for G4PolarizedComptonCrossSection:

Public Member Functions
	G4PolarizedComptonCrossSection ()
virtual	~G4PolarizedComptonCrossSection ()
virtual void	Initialize (G4double eps, G4double X, G4double phi, const G4StokesVector &p0, const G4StokesVector &p1, G4int flag=0)
G4double	XSection (const G4StokesVector &pol2, const G4StokesVector &pol3)
G4double	TotalXSection (G4double xmin, G4double xmax, G4double y, const G4StokesVector &pol0, const G4StokesVector &pol1)
G4StokesVector	GetPol2 ()
G4StokesVector	GetPol3 ()
Public Member Functions inherited from G4VPolarizedCrossSection
	G4VPolarizedCrossSection ()
virtual	~G4VPolarizedCrossSection ()
virtual void	Initialize (G4double, G4double, G4double, const G4StokesVector &p0, const G4StokesVector &p1, G4int flag=0)
virtual G4double	XSection (const G4StokesVector &pol2, const G4StokesVector &pol3)=0
virtual G4double	TotalXSection (G4double xmin, G4double xmax, G4double y, const G4StokesVector &pol0, const G4StokesVector &pol1)
virtual G4StokesVector	GetPol2 ()
virtual G4StokesVector	GetPol3 ()
G4double	GetYmin ()
virtual G4double	GetXmin (G4double y)
virtual G4double	GetXmax (G4double y)
void	SetMaterial (G4double A, G4double Z, G4double coul)

Additional Inherited Members
Protected Member Functions inherited from G4VPolarizedCrossSection
void	SetXmin (G4double xmin)
void	SetXmax (G4double xmax)
void	SetYmin (G4double ymin)
Protected Attributes inherited from G4VPolarizedCrossSection
G4double	fXmin
G4double	fXmax
G4double	fYmin
G4double	theA
G4double	theZ
G4double	fCoul

Detailed Description

Definition at line 57 of file G4PolarizedComptonCrossSection.hh.

Constructor & Destructor Documentation

G4PolarizedComptonCrossSection()

G4PolarizedComptonCrossSection::G4PolarizedComptonCrossSection

(

)

Definition at line 51 of file G4PolarizedComptonCrossSection.cc.

                                                               :
  gammaPol0(false), electronPol1(false), gammaPol2(false), electronPol3(false),
  epsilon(0.)
  {
  SetYmin(0.);
 
  //  G4cout<<"G4PolarizedComptonCrossSection() init\n";
 
  re2 = classic_electr_radius * classic_electr_radius * sqr(4*pi/hbarc);
  //  G4double unit_conversion = hbarc_squared ;
  //  G4cout<<" (keV)^2* m^2 ="<<unit_conversion<<"\n";
  phi0 = 0.; polXS = 0.; unpXS = 0.;
  phi2 = G4ThreeVector(0., 0., 0.);
  phi3 = G4ThreeVector(0., 0., 0.);
  polxx = polyy = polzz = polxz = polzx = polyz = polzy = polxy = polyx = 0.;
  diffXSFactor = 1.;
  totalXSFactor = 1.;
}

~G4PolarizedComptonCrossSection()

G4PolarizedComptonCrossSection::~G4PolarizedComptonCrossSection ( )

virtual

Definition at line 71 of file G4PolarizedComptonCrossSection.cc.

{}

Member Function Documentation

GetPol2()

G4StokesVector G4PolarizedComptonCrossSection::GetPol2 ( )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 215 of file G4PolarizedComptonCrossSection.cc.

{
  // Note, mean polarization can not contain correlation 
  // effects.
  return 1./phi0 * phi2;
}

Referenced by G4PolarizedComptonModel::SampleSecondaries().

GetPol3()

G4StokesVector G4PolarizedComptonCrossSection::GetPol3 ( )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 224 of file G4PolarizedComptonCrossSection.cc.

{
  // Note, mean polarization can not contain correlation 
  // effects.
  return 1./phi0 * phi3;
}

Referenced by G4PolarizedComptonModel::SampleSecondaries().

Initialize()

void G4PolarizedComptonCrossSection::Initialize ( G4double  eps, G4double  X, G4double  phi, const G4StokesVector &  p0, const G4StokesVector &  p1, G4int  flag = 0  )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 75 of file G4PolarizedComptonCrossSection.cc.

{
  G4double cosT = 1. - (1./eps - 1.)/X;
  if(cosT > 1.+1.e-8)  cosT = 1.;
  if(cosT < -1.-1.e-8) cosT = -1.;
  G4double cosT2 = cosT*cosT;
  G4double cosT3 = cosT2*cosT;
  G4double sinT2 = 1. - cosT2;
  if(sinT2 > 1. + 1.e-8) sinT2 = 1.;
  if(sinT2 < 0.)     sinT2 = 0.;
  G4double sinT = std::sqrt(sinT2);
  G4double cos2T = 2.*cosT2 - 1.;
  G4double sin2T = 2.*sinT*cosT;
  G4double eps2 = sqr(eps);
  DefineCoefficients(pol0,pol1);
  diffXSFactor = re2/(4.*X);
 
  // unpolarized Cross Section
  unpXS = (eps2 + 1. - eps*sinT2)/(2.*eps);
  // initial polarization dependence
  polXS = -sinT2*pol0.x() + (1. - eps)*sinT*polzx + ((eps2 - 1.)/eps)*cosT*polzz;
  polXS *= 0.5;
 
  phi0 = unpXS + polXS;
 
  if (flag == 2 ){
  // polarization of outgoing photon
  G4double PHI21 = -sinT2 + 0.5*(cos2T + 3.)*pol0.x() - ((1. - eps)/eps)*sinT*polzx;
  PHI21 *= 0.5;
  G4double PHI22 = cosT*pol0.y() + ((1. - eps)/(2.*eps))*sinT*polzy;
  G4double PHI23 = ((eps2 + 1.)/eps)*cosT*pol0.z() - ((1. - eps)/eps)*(eps*cosT2 + 1.)*pol1.z();
  PHI23 += 0.5*(1. - eps)*sin2T*pol1.x();
  PHI23 += (eps - 1.)*(-sinT2*polxz + sinT*polyy - 0.5*sin2T*polxx);
  PHI23 *= 0.5;
  phi2 = G4ThreeVector(PHI21, PHI22, PHI23);
 
  // polarization of outgoing electron
  G4double PHI32 = -sinT2*polxy + ((1. - eps)/eps)*sinT*polyz + 0.5*(cos2T + 3.)*pol1.y();
  PHI32 *= 0.5;
 
  G4double PHI31 = 0., PHI31add = 0., PHI33 = 0., PHI33add = 0.;
 
  if ((1. - eps) > 1.e-12){
    G4double helpVar = std::sqrt(eps2 - 2.*cosT*eps + 1.);
 
    PHI31 = (1. - eps)*(1. + cosT)*sinT*pol0.z();
    PHI31 += (-eps*cosT3 + eps*cosT2 + (eps - 2.)*cosT + eps)*pol1.x();
    PHI31 += -(eps*cosT2 - eps*cosT + cosT + 1.)*sinT*pol1.z();
    PHI31 /= 2.*helpVar;
 
    PHI31add = -eps*sqr(1. - cosT)*(1. + cosT)*polxx;
    PHI31add += (1. - eps)*sinT2*polyy;
    PHI31add += -(-eps2 + cosT*(cosT*eps - eps + 1.)*eps + eps - 1.)*sinT*polxz/eps;
    PHI31add /= 2.*helpVar;
    
    PHI33 = ((1. - eps)/eps)*(-eps*cosT2 + eps*(eps + 1.)*cosT - 1.)*pol0.z();
    PHI33 += -(eps*cosT2 + (1. - eps)*eps*cosT + 1.)*sinT*pol1.x();
    PHI33 += -(-eps2*cosT3 + eps*(eps2 - eps + 1.)*cosT2 - cosT + eps2)*pol1.z()/eps;
    PHI33 /= -2.*helpVar;
 
    PHI33add = (eps*(eps - cosT - 1.)*cosT + 1.)*sinT*polxx;
    PHI33add += -(-eps2 + cosT*eps + eps - 1.)*sinT2*polxz;
    PHI33add += (eps - 1.)*(cosT - eps)*sinT*polyy;
    PHI33add /= -2.*helpVar;
  }else{
     PHI31 = -pol1.z() - (X - 1.)*std::sqrt(1. - eps)*pol1.x()/std::sqrt(2.*X);
     PHI31add = -(-X*X*pol1.z() - 2.*X*(2.*pol0.z() - pol1.z()) - (4.*pol0.x() + 5.)*pol1.z())*(1. - eps)/(4.*X);
     
     PHI33 = pol1.x() - (X - 1.)*std::sqrt(1. - eps)*pol1.z()/std::sqrt(2.*X);
     PHI33add = -(X*X - 2.*X + 4.*pol0.x() + 5.)*(1. - eps)*pol1.x()/(4.*X);
  }
  phi3 = G4ThreeVector(PHI31 + PHI31add, PHI32, PHI33 + PHI33add);
    
  }
  unpXS *= diffXSFactor;
  polXS *= diffXSFactor;
  phi0 *= diffXSFactor;
  phi2 *= diffXSFactor;
  phi3 *= diffXSFactor;
  
}

Referenced by G4PolarizedComptonModel::SampleSecondaries().

TotalXSection()

G4double G4PolarizedComptonCrossSection::TotalXSection ( G4double  xmin, G4double  xmax, G4double  y, const G4StokesVector &  pol0, const G4StokesVector &  pol1  )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 187 of file G4PolarizedComptonCrossSection.cc.

{
  
  //  G4double k0 = gammaEnergy / electron_mass_c2 ;
  G4double k1 = 1 + 2*k0 ;
 
//   // pi*re^2
//   G4double re=2.81794e-15; //m
//   G4double barn=1.e-28; //m^2
  G4double Z=theZ;
 
  G4double unit = Z*pi*classic_electr_radius  
    * classic_electr_radius ; // *1./barn;
 
  G4double pre = unit/(sqr(k0)*sqr(1.+2.*k0));
 
  G4double xs_0 = ((k0 - 2.)*k0  -2.)*sqr(k1)*std::log(k1) + 2.*k0*(k0*(k0 + 1.)*(k0 + 8.) + 2.);       
  G4double xs_pol = (k0 + 1.)*sqr(k1)*std::log(k1) - 2.*k0*(5.*sqr(k0) + 4.*k0 + 1.);
 
  return pre*(xs_0/k0 + pol0.p3()*pol1.z()*xs_pol);
}

XSection()

G4double G4PolarizedComptonCrossSection::XSection ( const G4StokesVector &  pol2, const G4StokesVector &  pol3  )

virtual

Implements G4VPolarizedCrossSection.

Definition at line 160 of file G4PolarizedComptonCrossSection.cc.

{
  gammaPol2    = !(pol2==G4StokesVector::ZERO);
  electronPol3 = !(pol3==G4StokesVector::ZERO);
 
  G4double phi = 0.;
  // polarization independent part
  phi += phi0;
 
 
  if (gammaPol2) { 
    // part depending on the polarization of the final photon  
    phi += phi2*pol2;
  }
 
  if (electronPol3) {
    // part depending on the polarization of the final electron  
    phi += phi3*pol3;
  }
 
  // return cross section.
  return phi;
} 

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

• G4PolarizedComptonCrossSection.hh
• G4PolarizedComptonCrossSection.cc