| 1 | //
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| 2 | // ********************************************************************
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| 3 | // * License and Disclaimer *
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| 4 | // * *
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of *
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and *
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| 7 | // * conditions of the Geant4 Software License, included in the file *
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These *
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| 9 | // * include a list of copyright holders. *
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| 10 | // * *
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| 11 | // * Neither the authors of this software system, nor their employing *
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| 12 | // * institutes,nor the agencies providing financial support for this *
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| 13 | // * work make any representation or warranty, express or implied, *
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| 14 | // * regarding this software system or assume any liability for its *
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| 15 | // * use. Please see the license in the file LICENSE and URL above *
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| 16 | // * for the full disclaimer and the limitation of liability. *
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| 17 | // * *
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| 18 | // * This code implementation is the result of the scientific and *
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| 19 | // * technical work of the GEANT4 collaboration. *
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| 20 | // * By using, copying, modifying or distributing the software (or *
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| 21 | // * any work based on the software) you agree to acknowledge its *
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| 22 | // * use in resulting scientific publications, and indicate your *
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| 23 | // * acceptance of all terms of the Geant4 Software license. *
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| 24 | // ********************************************************************
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| 25 | //
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| 26 | //
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| 27 | //
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| 28 | ///////////////////////////////////////////////////////////////////////////
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| 29 | //
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| 30 | // Rough model describing a gamma function distributed radiator of X-ray
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| 31 | // transition radiation. XTR is considered to flux after radiator!
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| 32 | // Thicknesses of plates and gas gaps are distributed according to gamma
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| 33 | // distribution. x are thicknesses of plates or gas gaps:
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| 34 | //
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| 35 | // p(x) = (alpha/<x>)^alpha * x^(alpha-1) * std::exp(-alpha*x/<x>) / G(alpha)
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| 36 | //
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| 37 | // G(alpha) is Euler's gamma function.
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| 38 | // Plates have mean <x> = fPlateThick > 0 and power alpha = fAlphaPlate > 0 :
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| 39 | // Gas gaps have mean <x> = fGasThick > 0 and power alpha = fAlphaGas > 0 :
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| 40 | // We suppose that:
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| 41 | // formation zone ~ mean thickness << absorption length
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| 42 | // for each material and in the range 1-100 keV. This allows us to simplify
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| 43 | // interference effects in radiator stack (GetStackFactor method).
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| 44 | //
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| 45 | //
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| 46 | // History:
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| 47 | //
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| 48 | // 03.10.05 V. Grichine, first version
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| 49 | //
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| 50 |
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| 51 | #ifndef G4XTRGammaRadModel_h
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| 52 | #define G4XTRGammaRadModel_h 1
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| 53 |
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| 54 | #include "G4VXTRenergyLoss.hh"
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| 55 |
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| 56 | class G4XTRGammaRadModel : public G4VXTRenergyLoss
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| 57 | {
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| 58 | public:
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| 59 |
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| 60 | G4XTRGammaRadModel (G4LogicalVolume *anEnvelope,
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| 61 | G4double,G4double,
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| 62 | G4Material*,G4Material*,
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| 63 | G4double,G4double,G4int,
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| 64 | const G4String & processName = "XTRgammaRadiator" );
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| 65 | virtual ~G4XTRGammaRadModel ();
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| 66 |
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| 67 | // Pure virtual function from base class
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| 68 |
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| 69 | G4double GetStackFactor( G4double energy, G4double gamma, G4double varAngle);
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| 70 |
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| 71 | private:
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| 72 |
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| 73 | // G4double fAlphaPlate, fAlphaGas ;
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| 74 | };
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| 75 |
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| 76 | #endif
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