G4XTRGammaRadModel.cc

Go to the documentation of this file.

//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
//
//
 
#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<<"Gammma 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 ;
}
 
 
//
//
////////////////////////////////////////////////////////////////////////////