G4XTRGammaRadModel.cc

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#include <complex>

#include "G4XTRGammaRadModel.hh"
#include "Randomize.hh"

#include "G4Gamma.hh"

using namespace std;

//
// Constructor, destructor

G4XTRGammaRadModel::G4XTRGammaRadModel(G4LogicalVolume* anEnvelope,
                                     G4double alphaPlate,
                                     G4double alphaGas,
                                     G4Material* foilMat,G4Material* gasMat,
                                     G4double a, G4double b, G4int n,
                                     const G4String& processName) :
  G4VXTRenergyLoss(anEnvelope,foilMat,gasMat,a,b,n,processName)
{
  G4cout<<"Gamma distributed X-ray TR radiator model is called"<<G4endl ;

  // Build energy and angular integral spectra of X-ray TR photons from
  // a radiator

  fAlphaPlate = alphaPlate ;
  fAlphaGas   = alphaGas   ;
  G4cout<<"fAlphaPlate = "<<fAlphaPlate<<" ; fAlphaGas = "<<fAlphaGas<<G4endl ;
  fExitFlux = true;
  //  BuildTable() ;
}


G4XTRGammaRadModel::~G4XTRGammaRadModel()
{
  ;
}



//
// Rough approximation for radiator interference factor for the case of
// fully GamDistr radiator. The plate and gas gap thicknesses are distributed 
// according to exponent. The mean values of the plate and gas gap thicknesses 
// are supposed to be about XTR formation zones but much less than 
// mean absorption length of XTR photons in coresponding material.

G4double 
G4XTRGammaRadModel::GetStackFactor( G4double energy, 
                                         G4double gamma, G4double varAngle )
{
  G4double result, Qa, Qb, Q, Za, Zb, Ma, Mb ;
  
  Za = GetPlateFormationZone(energy,gamma,varAngle) ;
  Zb = GetGasFormationZone(energy,gamma,varAngle) ;

  Ma = GetPlateLinearPhotoAbs(energy) ;
  Mb = GetGasLinearPhotoAbs(energy) ;

  Qa = ( 1.0 + fPlateThick*Ma/fAlphaPlate ) ;
  Qa = std::pow(Qa,-fAlphaPlate) ;
  Qb = ( 1.0 + fGasThick*Mb/fAlphaGas ) ;
  Qb = std::pow(Qb,-fAlphaGas) ;
  Q  = Qa*Qb ;

  G4complex Ca(1.0+0.5*fPlateThick*Ma/fAlphaPlate,fPlateThick/Za/fAlphaPlate) ; 
  G4complex Cb(1.0+0.5*fGasThick*Mb/fAlphaGas,fGasThick/Zb/fAlphaGas) ; 

  G4complex Ha = std::pow(Ca,-fAlphaPlate) ;  
  G4complex Hb = std::pow(Cb,-fAlphaGas) ;
  G4complex H  = Ha*Hb ;

  G4complex F1 = ( 0.5*(1+Qa)*(1.0+H) - Ha - Qa*Hb )/(1.0-H) ;

  G4complex F2 = (1.0-Ha)*(Qa-Ha)*Hb/(1.0-H)/(Q-H) ;

  F2          *= std::pow(Q,G4double(fPlateNumber)) - std::pow(H,fPlateNumber) ;

  result      = ( 1. - std::pow(Q,G4double(fPlateNumber)) )/( 1. - Q ) ;

  G4complex stack  = result*F1;
            stack += F2;
            stack *= 2.0*OneInterfaceXTRdEdx(energy,gamma,varAngle);

      result = std::real(stack);

      // result     *= 2.0*std::real(F1);
      // result     += 2.0*std::real(F2);

  return      result ;
}


//
//