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// $Id$
//
// 
///////////////////////////////////////////////////////////////////////////
// 
// Rough process describing a radiator of X-ray transition radiation.  
// Thicknesses of plates and gas gaps are distributed according to gamma 
// distribution. x are thicknesses of plates or gas gaps:
//
// p(x) = (alpha/<x>)^alpha * x^(alpha-1) * std::exp(-alpha*x/<x>) / G(alpha)
//
// G(alpha) is Euler's gamma function.
// Plates have mean <x> = fPlateThick > 0 and power alpha = fAlphaPlate > 0 :
// Gas gaps have mean <x> = fGasThick > 0 and power alpha = fAlphaGas > 0 :
// We suppose that:
// formation zone ~ mean thickness << absorption length
// for each material and in the range 1-100 keV. This allows us to simplify
// interference effects in radiator stack (GetStackFactor method).
// 
// 
// History:
// 21.01.02 V. Grichine, first version 
//


#ifndef G4GammaXTRadiator_h
#define G4GammaXTRadiator_h 1

#include "G4VXTRenergyLoss.hh"

class G4GammaXTRadiator : public G4VXTRenergyLoss
{
public:

   G4GammaXTRadiator (G4LogicalVolume *anEnvelope,
                           G4double,G4double,
                           G4Material*,G4Material*,
                        G4double,G4double,G4int,
                        const G4String & processName = "XTRgammaRadiator");
  ~G4GammaXTRadiator ();

  // Pure virtual function from base class

  G4double GetStackFactor( G4double energy, G4double gamma, G4double varAngle);

private:

};

#endif