G4PolarizedAnnihilationCrossSection Class Reference

#include <G4PolarizedAnnihilationCrossSection.hh>

Inheritance diagram for G4PolarizedAnnihilationCrossSection:

Public Member Functions
	G4PolarizedAnnihilationCrossSection ()
virtual	~G4PolarizedAnnihilationCrossSection ()
virtual void	Initialize (G4double eps, G4double gamma, G4double phi, const G4StokesVector &p0, const G4StokesVector &p1, G4int flag=0)
G4double	DiceEpsilon ()
virtual G4double	XSection (const G4StokesVector &pol2, const G4StokesVector &pol3)
virtual G4double	TotalXSection (G4double xmin, G4double xmax, G4double y, const G4StokesVector &pol0, const G4StokesVector &pol1)
G4StokesVector	GetPol2 ()
G4StokesVector	GetPol3 ()
virtual G4double	GetXmin (G4double y)
virtual G4double	GetXmax (G4double y)
G4double	getVar (G4int)
void	getCoeff ()
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 55 of file G4PolarizedAnnihilationCrossSection.hh.

Constructor & Destructor Documentation

G4PolarizedAnnihilationCrossSection()

G4PolarizedAnnihilationCrossSection::G4PolarizedAnnihilationCrossSection

(

)

Definition at line 52 of file G4PolarizedAnnihilationCrossSection.cc.

                                                                         :
  polxx(0.), polyy(0.), polzz(0.), polxz(0.), polzx(0.), polxy(0.), 
  polyx(0.), polyz(0.), polzy(0.),
  re2(1.), diffXSFactor(1.), totalXSFactor(1.),
  phi0(0.)
{
  re2 = classic_electr_radius * classic_electr_radius;
  phi2 = G4ThreeVector(0., 0., 0.);
  phi3 = G4ThreeVector(0., 0., 0.);
  dice = 0.;
  polXS= 0.;
  unpXS = 0.;
  ISPxx=ISPyy=ISPzz=ISPnd=0.;
}

~G4PolarizedAnnihilationCrossSection()

G4PolarizedAnnihilationCrossSection::~G4PolarizedAnnihilationCrossSection ( )

virtual

Definition at line 69 of file G4PolarizedAnnihilationCrossSection.cc.

{
}

Member Function Documentation

DiceEpsilon()

G4double G4PolarizedAnnihilationCrossSection::DiceEpsilon

(

)

Definition at line 317 of file G4PolarizedAnnihilationCrossSection.cc.

{
  return dice;
}

Referenced by G4PolarizedAnnihilationModel::SampleSecondaries().

getCoeff()

void G4PolarizedAnnihilationCrossSection::getCoeff

(

)

GetPol2()

G4StokesVector G4PolarizedAnnihilationCrossSection::GetPol2 ( )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 272 of file G4PolarizedAnnihilationCrossSection.cc.

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

Referenced by G4PolarizedAnnihilationModel::SampleSecondaries().

GetPol3()

G4StokesVector G4PolarizedAnnihilationCrossSection::GetPol3 ( )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 281 of file G4PolarizedAnnihilationCrossSection.cc.

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

Referenced by G4PolarizedAnnihilationModel::SampleSecondaries().

getVar()

G4double G4PolarizedAnnihilationCrossSection::getVar

(

G4int

choice

)

Definition at line 322 of file G4PolarizedAnnihilationCrossSection.cc.

{
  if (choice == -1) return polXS/unpXS;
  if (choice == 0) return unpXS;
  if (choice == 1) return ISPxx;
  if (choice == 2) return ISPyy;
  if (choice == 3) return ISPzz;
  if (choice == 4) return ISPnd;
  return 0;
}

Referenced by G4PolarizedAnnihilationModel::SampleSecondaries().

GetXmax()

G4double G4PolarizedAnnihilationCrossSection::GetXmax ( G4double  y )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 311 of file G4PolarizedAnnihilationCrossSection.cc.

{
  return 0.5*(1.+std::sqrt((y-1.)/(y+1.)));
}

GetXmin()

G4double G4PolarizedAnnihilationCrossSection::GetXmin ( G4double  y )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 307 of file G4PolarizedAnnihilationCrossSection.cc.

{
  return 0.5*(1.-std::sqrt((y-1.)/(y+1.)));
}

Initialize()

void G4PolarizedAnnihilationCrossSection::Initialize ( G4double  eps, G4double  gamma, G4double  phi, const G4StokesVector &  p0, const G4StokesVector &  p1, G4int  flag = 0  )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 90 of file G4PolarizedAnnihilationCrossSection.cc.

{
 
  diffXSFactor=re2/(gam - 1.);
  DefineCoefficients(pol0,pol1);
  //  
  // prepare dicing
  //
  dice = 0.;
  G4double symmXS = 0.125*((-1./sqr(gam + 1.))/sqr(eps) + 
               ((sqr(gam) + 4.*gam - 1.)/sqr(gam + 1.))/eps - 1.);
  //
  //
  //
  G4ThreeVector epsVector(1./sqr(eps), 1./eps, 1.);
  G4ThreeVector oneEpsVector(1./sqr(1. - eps), 1./(1.-eps), 1.);
  G4ThreeVector sumEpsVector(epsVector + oneEpsVector);
  G4ThreeVector difEpsVector(epsVector - oneEpsVector);
  G4ThreeVector calcVector(0., 0., 0.);
  //
  // temporary variables
  //
  G4double helpVar2 = 0., helpVar1 = 0.;
  //
  // unpolarised contribution
  //
  helpVar1 = (gam*gam + 4.*gam + 1.)/sqr(gam + 1.);
  helpVar2 = -1./sqr(gam + 1.);
  calcVector = G4ThreeVector(helpVar2, helpVar1, -1.);
  unpXS = 0.125 * calcVector * sumEpsVector;
 
  // initial particles polarised contribution
  helpVar2 = 1./sqr(gam + 1.);
  helpVar1 = -(gam*gam + 4.*gam + 1.)/sqr(gam + 1.);
  calcVector = G4ThreeVector(helpVar2, helpVar1, 0.5*(gam + 3.));
  ISPxx = 0.25*(calcVector * sumEpsVector)/(gam - 1.);
 
  helpVar1 = 1./sqr(gam + 1.);
  calcVector = G4ThreeVector(-helpVar1, 2.*gam*helpVar1, -1.);
  ISPyy = 0.125 * calcVector * sumEpsVector;
 
  helpVar1 = 1./(gam - 1.);
  helpVar2 = 1./sqr(gam + 1.);
  calcVector = G4ThreeVector(-(gam*gam + 1.)*helpVar2,(gam*gam*(gam + 1.) + 7.*gam + 3.)*helpVar2, -(gam + 3.));
  ISPzz = 0.125*helpVar1*(calcVector * sumEpsVector);
 
  helpVar1 = std::sqrt(std::fabs(eps*(1. - eps)*2.*(gam + 1.) - 1.));
  calcVector = G4ThreeVector(-1./(gam*gam - 1.), 2./(gam - 1.), 0.);
  ISPnd = 0.125*(calcVector * difEpsVector) * helpVar1;
 
  polXS = 0.;  
  polXS += ISPxx*polxx;
  polXS += ISPyy*polyy;
  polXS += ISPzz*polzz;
  polXS += ISPnd*(polzx + polxz);
  phi0 = unpXS + polXS;
  dice = symmXS;
  //  if(polzz != 0.) dice *= (1. + std::fabs(polzz*ISPzz/unpXS));
  if(polzz != 0.) {
    dice *= (1. + (polzz*ISPzz/unpXS));
    if (dice<0.) dice=0.;
  }
    // prepare final state coefficients
  if (flag==2) {
    //
    // circular polarisation
    //
    G4double circ1 = 0., circ2 = 0., circ3 = 0.;
    helpVar1 = 8.*sqr(1. - eps)*sqr(eps)*(gam - 1.)*sqr(gam + 1.)/std::sqrt(gam*gam - 1.);
    helpVar2 =  sqr(gam + 1.)*sqr(eps)*(-2.*eps + 3.) - (gam*gam + 3.*gam + 2.)*eps;
    circ1 = helpVar2 + gam;
    circ1 /= helpVar1;
    circ2 = helpVar2 + 1.;
    circ2 /= helpVar1;
    helpVar1 = std::sqrt(std::fabs(eps*(1. - eps)*2.*(gam + 1.) - 1.));
    helpVar1 /= std::sqrt(gam*gam - 1.);
    calcVector = G4ThreeVector(1., -2.*gam, 0.);
    circ3 = 0.125*(calcVector * sumEpsVector)/(gam + 1.);
    circ3 *= helpVar1;
 
    phi2.setZ( circ2*pol1.z() + circ1*pol0.z() + circ3*(pol1.x() + pol0.x()));
    phi3.setZ(-circ1*pol1.z() - circ2*pol0.z() - circ3*(pol1.x() + pol0.x()));
    //
    // common to both linear polarisation
    //
    calcVector = G4ThreeVector(-1., 2.*gam, 0.);
    G4double linearZero = 0.125*(calcVector * sumEpsVector)/sqr(gam + 1.);
    //   
    //        Linear Polarisation #1 
    //
    helpVar1 = std::sqrt(std::fabs(2.*(gam + 1.)*(1. - eps)*eps - 1.))/((gam + 1.)*eps*(1. - eps));
    helpVar2 = helpVar1*helpVar1;
    //
    // photon 1
    //
    G4double diagContrib = 0.125*helpVar2*(polxx + polyy - polzz);
    G4double nonDiagContrib = 0.125*helpVar1*(-polxz/(1. - eps) + polzx/eps);
 
    phi2.setX(linearZero + diagContrib + nonDiagContrib);
    //
    // photon 2
    //
    nonDiagContrib = 0.125*helpVar1*(polxz/eps - polzx/(1. - eps));
 
 
    phi3.setX(linearZero + diagContrib + nonDiagContrib);
   //   
   //        Linear Polarisation #2
   //
    helpVar1 = std::sqrt(gam*gam - 1.)*(2.*(gam + 1.)*eps*(1. - eps) - 1.);
    helpVar1 /= 8.*sqr(1. - eps)*sqr(eps)*sqr(gam + 1.)*(gam - 1.);
    helpVar2 = std::sqrt((gam*gam - 1.)*std::fabs(2.*(gam + 1.)*eps*(1. - eps) - 1.));
    helpVar2 /= 8.*sqr(1. - eps)*sqr(eps)*sqr(gam + 1.)*(gam - 1.);
 
    G4double contrib21 = (-polxy + polyx)*helpVar1;
    G4double contrib32 = -(eps*(gam + 1.) - 1.)*polyz + (eps*(gam + 1.) - gam)*polzy;
 
             contrib32 *=helpVar2;
    phi2.setY(contrib21 + contrib32);
 
             contrib32 = -(eps*(gam + 1.) - gam)*polyz + (eps*(gam + 1.) - 1.)*polzy;
             contrib32 *=helpVar2;
    phi3.setY(contrib21 + contrib32);
 
  }
  phi0 *= diffXSFactor;
  phi2 *= diffXSFactor;
  phi3 *= diffXSFactor;
}

Referenced by G4PolarizedAnnihilationModel::SampleSecondaries().

TotalXSection()

G4double G4PolarizedAnnihilationCrossSection::TotalXSection ( G4double  xmin, G4double  xmax, G4double  y, const G4StokesVector &  pol0, const G4StokesVector &  pol1  )

virtual

Reimplemented from G4VPolarizedCrossSection.

Definition at line 238 of file G4PolarizedAnnihilationCrossSection.cc.

{
  totalXSFactor =pi*re2/(gam + 1.);  // atomic number ignored  
  DefineCoefficients(pol0,pol1);
 
  G4double xs = 0.;
 
 
  G4double gam2 = gam*gam;
  G4double sqrtgam1 = std::sqrt(gam2 - 1.);
  G4double logMEM  = std::log(gam+sqrtgam1);
  G4double unpME = (gam*(gam + 4.) + 1.)*logMEM;
  unpME += -(gam + 3.)*sqrtgam1;
  unpME /= 4.*(gam2 - 1.);
//   G4double longPart = - 2.*(gam*(gam + 4.) + 1.)*logMEM; 
//   longPart += (gam*(gam + 4.) + 7.)*sqrtgam1;
//   longPart /= 4.*sqr(gam - 1.)*(gam + 1.);
  G4double longPart = (3+gam*(gam*(gam + 1.) + 7.))*logMEM; 
  longPart += - (5.+ gam*(3*gam + 4.))*sqrtgam1;
  longPart /= 4.*sqr(gam - 1.)*(gam + 1.);
  G4double tranPart = -(5*gam + 1.)*logMEM;
  tranPart += (gam + 5.)*sqrtgam1;
  tranPart /= 4.*sqr(gam - 1.)*(gam + 1.);
                   
  xs += unpME;
  xs += polzz*longPart;
  xs += (polxx + polyy)*tranPart;
 
  return xs*totalXSFactor;
}

Referenced by G4PolarizedAnnihilationModel::ComputeAsymmetriesPerElectron().

XSection()

G4double G4PolarizedAnnihilationCrossSection::XSection ( const G4StokesVector &  pol2, const G4StokesVector &  pol3  )

virtual

Implements G4VPolarizedCrossSection.

Definition at line 229 of file G4PolarizedAnnihilationCrossSection.cc.

{
  G4double xs=phi0+pol2*phi2+pol3*phi3;
  return xs;
}

---

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

• G4PolarizedAnnihilationCrossSection.hh
• G4PolarizedAnnihilationCrossSection.cc