[819] | 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 | // GEANT4 Class file |
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| 30 | // |
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| 31 | // |
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| 32 | // File name: G4ModifiedTsai |
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| 33 | // |
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| 34 | // Author: Andreia Trindade (andreia@lip.pt) |
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| 35 | // Pedro Rodrigues (psilva@lip.pt) |
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| 36 | // Luis Peralta (luis@lip.pt) |
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| 37 | // |
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| 38 | // Creation date: 21 March 2003 |
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| 39 | // |
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| 40 | // Modifications: |
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| 41 | // 21 Mar 2003 A. Trindade First implementation acording with new design |
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| 42 | // 24 Mar 2003 & Fix in Tsai generator in order to prevent theta generation above pi |
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| 43 | // |
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| 44 | // Class Description: |
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| 45 | // |
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| 46 | // Concrete base class for Bremsstrahlung Angular Distribution Generation - Tsai Model |
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| 47 | // |
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| 48 | // Class Description: End |
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| 49 | // |
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| 50 | // ------------------------------------------------------------------- |
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| 51 | // |
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| 52 | // |
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| 53 | |
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| 54 | #include "G4ModifiedTsai.hh" |
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| 55 | #include "Randomize.hh" |
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| 56 | // |
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| 57 | |
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| 58 | G4ModifiedTsai::G4ModifiedTsai(const G4String& name):G4VBremAngularDistribution(name) |
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| 59 | {;} |
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| 60 | |
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| 61 | // |
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| 62 | |
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| 63 | G4ModifiedTsai::~G4ModifiedTsai() |
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| 64 | {;} |
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| 65 | |
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| 66 | // |
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| 67 | |
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| 68 | G4double G4ModifiedTsai::PolarAngle(const G4double initial_energy, |
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| 69 | const G4double, // final_energy |
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| 70 | const G4int ) // Z |
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| 71 | { |
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| 72 | |
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| 73 | // Sample gamma angle (Z - axis along the parent particle). |
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| 74 | // Universal distribution suggested by L. Urban (Geant3 manual (1993) |
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| 75 | // Phys211) derived from Tsai distribution (Rev Mod Phys 49,421(1977)) |
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| 76 | |
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| 77 | G4double totalEnergy = initial_energy + electron_mass_c2; |
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| 78 | |
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| 79 | const G4double a1 = 0.625, a2 = 3.*a1, d = 27.; |
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| 80 | G4double u, theta = 0; |
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| 81 | |
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| 82 | do{ |
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| 83 | u = - std::log(G4UniformRand()*G4UniformRand()); |
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| 84 | |
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| 85 | if (9./(9.+d) > G4UniformRand()) u /= a1; |
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| 86 | else u /= a2; |
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| 87 | |
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| 88 | theta = u*electron_mass_c2/totalEnergy; |
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| 89 | }while(u > (totalEnergy*pi/electron_mass_c2)); |
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| 90 | |
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| 91 | return theta; |
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| 92 | } |
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| 93 | // |
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| 94 | |
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| 95 | void G4ModifiedTsai::PrintGeneratorInformation() const |
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| 96 | { |
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| 97 | |
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| 98 | G4cout << "\n" << G4endl; |
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| 99 | G4cout << "Bremsstrahlung Angular Generator is Modified Tsai" << G4endl; |
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| 100 | G4cout << "Universal distribution suggested by L. Urban (Geant3 manual (1993) Phys211)" << G4endl; |
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| 101 | G4cout << "Derived from Tsai distribution (Rev Mod Phys 49,421(1977)) \n" << G4endl; |
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| 102 | } |
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