G4XTRRegularRadModel.cc

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#include <complex>

#include "G4XTRRegularRadModel.hh"
#include "G4PhysicalConstants.hh"
#include "Randomize.hh"

#include "G4Gamma.hh"
using namespace std;

//
// Constructor, destructor

G4XTRRegularRadModel::G4XTRRegularRadModel(G4LogicalVolume *anEnvelope,
                                         G4Material* foilMat,G4Material* gasMat,
                                         G4double a, G4double b, G4int n,
                                         const G4String& processName) :
  G4VXTRenergyLoss(anEnvelope,foilMat,gasMat,a,b,n,processName)  
{
  G4cout<<" XTR Regular discrete radiator model is called"<<G4endl ;

  fExitFlux = true;

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

  // BuildTable() ;
}


G4XTRRegularRadModel::~G4XTRRegularRadModel()
{
  ;
}

//
//

G4double G4XTRRegularRadModel::SpectralXTRdEdx(G4double energy)
{
  G4double result, sum = 0., tmp, cof1, cof2, cofMin, cofPHC, theta2, theta2k; 
    G4double aMa, bMb ,sigma, dump;
  G4int k, kMax, kMin;

  aMa = fPlateThick*GetPlateLinearPhotoAbs(energy);
  bMb = fGasThick*GetGasLinearPhotoAbs(energy);
  sigma = 0.5*(aMa + bMb);
  dump = std::exp(-fPlateNumber*sigma);
  if(verboseLevel > 2)  G4cout<<" dump = "<<dump<<G4endl;  
  cofPHC  = 4*pi*hbarc;
  tmp     = (fSigma1 - fSigma2)/cofPHC/energy;  
  cof1    = fPlateThick*tmp;
  cof2    = fGasThick*tmp;

  cofMin  =  energy*(fPlateThick + fGasThick)/fGamma/fGamma;
  cofMin += (fPlateThick*fSigma1 + fGasThick*fSigma2)/energy;
  cofMin /= cofPHC;

  theta2 = cofPHC/(energy*(fPlateThick + fGasThick));

  //  if (fGamma < 1200) kMin = G4int(cofMin);  // 1200 ?
  // else               kMin = 1;


  kMin = G4int(cofMin);
  if (cofMin > kMin) kMin++;

  // tmp  = (fPlateThick + fGasThick)*energy*fMaxThetaTR;
  // tmp /= cofPHC;
  // kMax = G4int(tmp);
  // if(kMax < 0) kMax = 0;
  // kMax += kMin;
  

  kMax = kMin + 49; //  19; // kMin + G4int(tmp);

  // tmp /= fGamma;
  // if( G4int(tmp) < kMin ) kMin = G4int(tmp);

  if(verboseLevel > 2)
  {    
    G4cout<<cof1<<"     "<<cof2<<"        "<<cofMin<<G4endl;
    G4cout<<"kMin = "<<kMin<<";    kMax = "<<kMax<<G4endl;
  }
  for( k = kMin; k <= kMax; k++ )
  {
    tmp    = pi*fPlateThick*(k + cof2)/(fPlateThick + fGasThick);
    result = (k - cof1)*(k - cof1)*(k + cof2)*(k + cof2);
    // tmp = std::sin(tmp)*std::sin(tmp)*std::abs(k-cofMin)/result;
    if( k == kMin && kMin == G4int(cofMin) )
    {
      sum   += 0.5*std::sin(tmp)*std::sin(tmp)*std::abs(k-cofMin)/result;
    }
    else
    {
      sum   += std::sin(tmp)*std::sin(tmp)*std::abs(k-cofMin)/result;
    }
    theta2k = std::sqrt(theta2*std::abs(k-cofMin));

    if(verboseLevel > 2)
    {    
      // G4cout<<"k = "<<k<<"; sqrt(theta2k) = "<<theta2k<<"; tmp = "<<std::sin(tmp)*std::sin(tmp)*std::abs(k-cofMin)/result
      //     <<";    sum = "<<sum<<G4endl;  
      G4cout<<k<<"   "<<theta2k<<"     "<<std::sin(tmp)*std::sin(tmp)*std::abs(k-cofMin)/result
              <<"      "<<sum<<G4endl;  
    }  
  }
  result = 2*( cof1 + cof2 )*( cof1 + cof2 )*sum/energy;
  // result *= ( 1 - std::exp(-0.5*fPlateNumber*sigma) )/( 1 - std::exp(-0.5*sigma) );  
  // fPlateNumber;
  result *= dump*( -1 + dump + 2*fPlateNumber ); 
  /*  
  fEnergy = energy;
  //  G4Integrator<G4VXTRenergyLoss,G4double(G4VXTRenergyLoss::*)(G4double)> integral;
  G4Integrator<G4TransparentRegXTRadiator,G4double(G4VXTRenergyLoss::*)(G4double)> integral;
 
  tmp = integral.Legendre96(this,&G4VXTRenergyLoss::SpectralAngleXTRdEdx,
                             0.0,0.3*fMaxThetaTR) +
      integral.Legendre96(this,&G4VXTRenergyLoss::SpectralAngleXTRdEdx,
                             0.3*fMaxThetaTR,0.6*fMaxThetaTR) +         
      integral.Legendre96(this,&G4VXTRenergyLoss::SpectralAngleXTRdEdx,
                             0.6*fMaxThetaTR,fMaxThetaTR) ;
  result += tmp;
  */
  return result;
}



//
// Approximation for radiator interference factor for the case of
// fully Regular radiator. The plate and gas gap thicknesses are fixed .
// 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 
G4XTRRegularRadModel::GetStackFactor( G4double energy, 
                                         G4double gamma, G4double varAngle )
{
  G4double result, Qa, Qb, Q, aZa, bZb, aMa, bMb, I2 ;
  
  aZa = fPlateThick/GetPlateFormationZone(energy,gamma,varAngle) ;
  bZb = fGasThick/GetGasFormationZone(energy,gamma,varAngle) ;

  aMa = fPlateThick*GetPlateLinearPhotoAbs(energy) ;
  bMb = fGasThick*GetGasLinearPhotoAbs(energy) ;

  Qa = std::exp(-aMa) ;
  Qb = std::exp(-bMb) ;
  Q  = Qa*Qb ;

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

  G4complex Ha( std::exp(-0.5*aMa)*std::cos(aZa),
               -std::exp(-0.5*aMa)*std::sin(aZa)   ) ; 
 
  G4complex Hb( std::exp(-0.5*bMb)*std::cos(bZb),
               -std::exp(-0.5*bMb)*std::sin(bZb)    ) ;

  G4complex H  = Ha*Hb ;

  G4complex Hs = std::conj(H) ;

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

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

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

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

  result      *= (1 - Qa)*(1 + Qa - 2*std::sqrt(Qa)*std::cos(aZa)) ;

  result      /= (1 - std::sqrt(Q))*(1 - std::sqrt(Q)) + 
                  4*std::sqrt(Q)*std::sin(0.5*(aZa+bZb))*std::sin(0.5*(aZa+bZb)) ;

  I2           = 1.; // 2.0*std::real(F2) ;

  I2           /= (1 - std::sqrt(Q))*(1 - std::sqrt(Q)) + 
                  4*std::sqrt(Q)*std::sin(0.5*(aZa+bZb))*std::sin(0.5*(aZa+bZb)) ;

  I2           /= Q*( (std::sqrt(Q)-std::cos(aZa+bZb))*(std::sqrt(Q)-std::cos(aZa+bZb)) + 
                      std::sin(aZa+bZb)*std::sin(aZa+bZb)   ) ;

  G4complex stack  = 2.*I2*F2;
            stack += result;
            stack *= OneInterfaceXTRdEdx(energy,gamma,varAngle);

            // result       += I2 ;
  result = std::real(stack);

  return      result ;
}


//
//

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