00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // 00027 // 00029 // 00030 // Rough model describing a gamma function distributed radiator of X-ray 00031 // transition radiation. XTR is considered to flux after radiator! 00032 // Thicknesses of plates and gas gaps are distributed according to gamma 00033 // distribution. x are thicknesses of plates or gas gaps: 00034 // 00035 // p(x) = (alpha/<x>)^alpha * x^(alpha-1) * std::exp(-alpha*x/<x>) / G(alpha) 00036 // 00037 // G(alpha) is Euler's gamma function. 00038 // Plates have mean <x> = fPlateThick > 0 and power alpha = fAlphaPlate > 0 : 00039 // Gas gaps have mean <x> = fGasThick > 0 and power alpha = fAlphaGas > 0 : 00040 // We suppose that: 00041 // formation zone ~ mean thickness << absorption length 00042 // for each material and in the range 1-100 keV. This allows us to simplify 00043 // interference effects in radiator stack (GetStackFactor method). 00044 // 00045 // 00046 // History: 00047 // 00048 // 03.10.05 V. Grichine, first version 00049 // 00050 00051 #ifndef G4XTRGammaRadModel_h 00052 #define G4XTRGammaRadModel_h 1 00053 00054 #include "G4VXTRenergyLoss.hh" 00055 00056 class G4XTRGammaRadModel : public G4VXTRenergyLoss 00057 { 00058 public: 00059 00060 G4XTRGammaRadModel (G4LogicalVolume *anEnvelope, 00061 G4double,G4double, 00062 G4Material*,G4Material*, 00063 G4double,G4double,G4int, 00064 const G4String & processName = "XTRgammaRadiator" ); 00065 virtual ~G4XTRGammaRadModel (); 00066 00067 // Pure virtual function from base class 00068 00069 G4double GetStackFactor( G4double energy, G4double gamma, G4double varAngle); 00070 00071 private: 00072 00073 // G4double fAlphaPlate, fAlphaGas ; 00074 }; 00075 00076 #endif