| 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 | // $Id: G4Generator2BN.cc,v 1.9 2010/10/14 14:01:02 vnivanch Exp $
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| 27 | // GEANT4 tag $Name: geant4-09-04-ref-00 $
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| 28 | //
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| 29 | // -------------------------------------------------------------------
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| 30 | //
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| 31 | // GEANT4 Class file
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| 32 | //
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| 33 | //
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| 34 | // File name: G4Generator2BN
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| 35 | //
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| 36 | // Author: Andreia Trindade (andreia@lip.pt)
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| 37 | // Pedro Rodrigues (psilva@lip.pt)
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| 38 | // Luis Peralta (luis@lip.pt)
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| 39 | //
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| 40 | // Creation date: 21 June 2003
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| 41 | //
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| 42 | // Modifications:
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| 43 | // 21 Jun 2003 First implementation acording with new design
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| 44 | // 05 Nov 2003 MGP Fixed compilation warning
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| 45 | // 14 Mar 2004 Code optimization
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| 46 | //
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| 47 | // Class Description:
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| 48 | //
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| 49 | // Concrete base class for Bremsstrahlung Angular Distribution Generation
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| 50 | // 2BN Distribution
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| 51 | //
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| 52 | // Class Description: End
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| 53 | //
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| 54 | // -------------------------------------------------------------------
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| 55 | //
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| 56 |
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| 57 | #include "G4Generator2BN.hh"
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| 58 | #include "Randomize.hh"
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| 59 | //
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| 60 |
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| 61 | G4double G4Generator2BN::Atab[320] =
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| 62 | { 0.0264767, 0.0260006, 0.0257112, 0.0252475, 0.024792, 0.0243443, 0.0240726, 0.0236367,
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| 63 | 0.023209, 0.0227892, 0.0225362, 0.0221284, 0.0217282,0.0214894, 0.0211005, 0.0207189,
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| 64 | 0.0204935, 0.0201227, 0.0197588, 0.019546, 0.0191923,0.0188454, 0.0186445, 0.0183072,
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| 65 | 0.0179763, 0.0177866, 0.0174649, 0.0172828, 0.0169702,0.0166634, 0.0164915, 0.0161933,
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| 66 | 0.0160283, 0.0157384, 0.0155801, 0.0152981, 0.0151463,0.0148721, 0.0147263, 0.0144598,
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| 67 | 0.01432, 0.0140607, 0.0139267, 0.0136744, 0.0135459,0.0133005, 0.0131773, 0.0129385,
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| 68 | 0.0128205, 0.0125881, 0.012475, 0.0122488, 0.0121406,0.0119204, 0.0118167, 0.0117158,
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| 69 | 0.0115032, 0.0114067, 0.0111995, 0.0111072, 0.0110175,0.0108173, 0.0107316, 0.0105365,
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| 70 | 0.0104547, 0.0102646, 0.0101865, 0.010111, 0.00992684,0.0098548,0.00967532,0.00960671,
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| 71 | 0.00943171,0.00936643,0.00930328,0.0091337, 0.00907372,0.00890831,0.00885141,0.00869003,
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| 72 | 0.00863611,0.00858428,0.00842757,0.00837854,0.0082256,0.00817931,0.00803,0.00798639,
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| 73 | 0.00784058,0.00779958,0.00776046,0.00761866,0.00758201,0.00744346,0.00740928,0.00727384,
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| 74 | 0.00724201,0.00710969,0.00708004,0.00695074,0.00692333,0.00679688,0.00677166,0.00664801,
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| 75 | 0.00662484,0.00650396,0.00648286,0.00636458,0.00634545,0.00622977,0.00621258,0.00609936,
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| 76 | 0.00608412,0.00597331,0.00595991,0.00585143,0.00583988,0.0057337,0.0057239,0.00561991,
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| 77 | 0.0056119, 0.00551005,0.00550377,0.00540399,0.00539938,0.00530162,0.00529872,0.00520292,
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| 78 | 0.0051091, 0.00510777,0.00501582,0.00501608,0.00492594,0.00492781,0.00483942,0.0048429,
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| 79 | 0.00475622,0.00476127,0.00467625,0.00468287,0.00459947,0.00451785,0.00452581,0.00444573,
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| 80 | 0.00445522,0.00437664,0.00438768,0.00431057,0.00432316,0.00424745,0.0042616,0.00418726,
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| 81 | 0.004203, 0.00413, 0.00405869,0.00407563,0.00400561,0.00402414,0.00395536,0.00397553,
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| 82 | 0.00390795,0.00392975,0.00386339,0.00379862,0.00382167,0.00375805,0.00378276,0.00372031,
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| 83 | 0.00374678,0.00368538,0.00371363,0.00365335,0.00359463,0.0036242, 0.00356653,0.003598,
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| 84 | 0.00354139,0.00357481,0.00351921,0.00355464,0.00350005,0.0034471,0.00348403,0.00343208,
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| 85 | 0.0034712, 0.00342026,0.00346165,0.00341172,0.00345548,0.00340657,0.00335944,0.00340491,
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| 86 | 0.00335885,0.00340692,0.00336191,0.00341273,0.00336879,0.00342249,0.00337962,0.00333889,
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| 87 | 0.00339463,0.00335506,0.00341401,0.00337558,0.00343797,0.00340067,0.00336584,0.00343059,
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| 88 | 0.0033969, 0.00346557,0.00343302,0.00350594,0.00347448,0.00344563,0.00352163,0.00349383,
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| 89 | 0.00357485,0.00354807,0.00352395,0.00360885,0.00358571,0.00367661,0.00365446,0.00375194,
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| 90 | 0.00373078,0.00371234,0.00381532,0.00379787,0.00390882,0.00389241,0.00387881,0.00399675,
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| 91 | 0.00398425,0.00411183,0.00410042,0.00409197,0.00422843,0.00422123,0.00436974,0.0043637,
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| 92 | 0.00436082,0.00452075,0.00451934,0.00452125,0.00469406,0.00469756,0.00488741,0.00489221,
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| 93 | 0.00490102,0.00510782,0.00511801,0.00513271,0.0053589, 0.00537524,0.00562643,0.00564452,
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| 94 | 0.0056677, 0.00594482,0.00596999,0.0059999, 0.00630758,0.00634014,0.00637849,0.00672136,
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| 95 | 0.00676236,0.00680914,0.00719407,0.0072439, 0.00730063,0.0077349, 0.00779494,0.00786293,
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| 96 | 0.00835577,0.0084276, 0.00850759,0.00907162,0.00915592,0.00924925,0.00935226,0.00999779,
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| 97 | 0.0101059, 0.0102249, 0.0109763, 0.0111003, 0.0112367, 0.0113862, 0.0122637, 0.0124196,
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| 98 | 0.0125898, 0.0136311, 0.0138081, 0.0140011, 0.0142112, 0.0154536, 0.0156723, 0.0159099,
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| 99 | 0.016168, 0.0176664, 0.0179339, 0.0182246, 0.0185396, 0.020381, 0.0207026, 0.0210558,
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| 100 | 0.0214374, 0.0237377, 0.0241275, 0.0245528, 0.0250106, 0.0255038, 0.0284158, 0.0289213,
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| 101 | 0.0294621, 0.0300526, 0.0338619, 0.0344537, 0.0351108, 0.0358099, 0.036554, 0.0416399
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| 102 | };
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| 103 |
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| 104 | G4double G4Generator2BN::ctab[320] =
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| 105 | { 0.482253, 0.482253, 0.489021, 0.489021, 0.489021, 0.489021, 0.495933,
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| 106 | 0.495933, 0.495933, 0.495933, 0.502993, 0.502993, 0.502993, 0.510204,
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| 107 | 0.510204, 0.510204, 0.517572, 0.517572, 0.517572, 0.5251, 0.5251,
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| 108 | 0.5251, 0.532793, 0.532793, 0.532793, 0.540657, 0.540657, 0.548697,
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| 109 | 0.548697, 0.548697, 0.556917, 0.556917, 0.565323, 0.565323, 0.573921,
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| 110 | 0.573921, 0.582717, 0.582717, 0.591716, 0.591716, 0.600925, 0.600925,
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| 111 | 0.610352, 0.610352, 0.620001, 0.620001, 0.629882, 0.629882, 0.64,
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| 112 | 0.64, 0.650364, 0.650364, 0.660982, 0.660982, 0.671862, 0.683013,
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| 113 | 0.683013, 0.694444, 0.694444, 0.706165, 0.718184, 0.718184, 0.730514,
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| 114 | 0.730514, 0.743163, 0.743163, 0.756144, 0.769468, 0.769468, 0.783147,
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| 115 | 0.783147, 0.797194, 0.797194, 0.811622, 0.826446, 0.826446, 0.84168,
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| 116 | 0.84168, 0.857339, 0.857339, 0.873439, 0.889996, 0.889996, 0.907029,
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| 117 | 0.907029, 0.924556, 0.924556, 0.942596, 0.942596, 0.961169, 0.980296,
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| 118 | 0.980296, 1, 1, 1.0203, 1.0203, 1.04123, 1.04123,
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| 119 | 1.06281, 1.06281, 1.08507, 1.08507, 1.10803, 1.10803, 1.13173,
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| 120 | 1.13173, 1.1562, 1.1562, 1.18147, 1.18147, 1.20758, 1.20758,
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| 121 | 1.23457, 1.23457, 1.26247, 1.26247, 1.29132, 1.29132, 1.32118,
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| 122 | 1.32118, 1.35208, 1.35208, 1.38408, 1.38408, 1.41723, 1.41723,
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| 123 | 1.45159, 1.45159, 1.45159, 1.48721, 1.48721, 1.52416, 1.52416,
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| 124 | 1.5625, 1.5625, 1.60231, 1.60231, 1.64366, 1.64366, 1.68663,
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| 125 | 1.68663, 1.68663, 1.7313, 1.7313, 1.77778, 1.77778, 1.82615,
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| 126 | 1.82615, 1.87652, 1.87652, 1.92901, 1.92901, 1.98373, 1.98373,
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| 127 | 1.98373, 2.04082, 2.04082, 2.1004, 2.1004, 2.16263, 2.16263,
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| 128 | 2.22767, 2.22767, 2.22767, 2.29568, 2.29568, 2.36686, 2.36686,
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| 129 | 2.44141, 2.44141, 2.51953, 2.51953, 2.51953, 2.60146, 2.60146,
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| 130 | 2.68745, 2.68745, 2.77778, 2.77778, 2.87274, 2.87274, 2.87274,
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| 131 | 2.97265, 2.97265, 3.07787, 3.07787, 3.18878, 3.18878, 3.30579,
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| 132 | 3.30579, 3.30579, 3.42936, 3.42936, 3.55999, 3.55999, 3.69822,
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| 133 | 3.69822, 3.84468, 3.84468, 3.84468, 4, 4, 4.16493,
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| 134 | 4.16493, 4.34028, 4.34028, 4.34028, 4.52694, 4.52694, 4.7259,
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| 135 | 4.7259, 4.93827, 4.93827, 4.93827, 5.16529, 5.16529, 5.40833,
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| 136 | 5.40833, 5.40833, 5.66893, 5.66893, 5.94884, 5.94884, 6.25,
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| 137 | 6.25, 6.25, 6.57462, 6.57462, 6.92521, 6.92521, 6.92521,
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| 138 | 7.3046, 7.3046, 7.71605, 7.71605, 7.71605, 8.16327, 8.16327,
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| 139 | 8.65052, 8.65052, 8.65052, 9.18274, 9.18274, 9.18274, 9.76562,
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| 140 | 9.76562, 10.4058, 10.4058, 10.4058, 11.1111, 11.1111, 11.1111,
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| 141 | 11.8906, 11.8906, 12.7551, 12.7551, 12.7551, 13.7174, 13.7174,
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| 142 | 13.7174, 14.7929, 14.7929, 14.7929, 16, 16, 16,
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| 143 | 17.3611, 17.3611, 17.3611, 18.9036, 18.9036, 18.9036, 20.6612,
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| 144 | 20.6612, 20.6612, 22.6757, 22.6757, 22.6757, 22.6757, 25,
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| 145 | 25, 25, 27.7008, 27.7008, 27.7008, 27.7008, 30.8642,
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| 146 | 30.8642, 30.8642, 34.6021, 34.6021, 34.6021, 34.6021, 39.0625,
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| 147 | 39.0625, 39.0625, 39.0625, 44.4444, 44.4444, 44.4444, 44.4444,
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| 148 | 51.0204, 51.0204, 51.0204, 51.0204, 59.1716, 59.1716, 59.1716,
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| 149 | 59.1716, 59.1716, 69.4444, 69.4444, 69.4444, 69.4444, 82.6446,
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| 150 | 82.6446, 82.6446, 82.6446, 82.6446, 100
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| 151 | };
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| 152 |
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| 153 |
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| 154 | G4Generator2BN::G4Generator2BN(const G4String&)
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| 155 | : G4VBremAngularDistribution("AngularGen2BN")
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| 156 | {
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| 157 | b = 1.2;
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| 158 | index_min = -300;
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| 159 | index_max = 20;
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| 160 |
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| 161 | // Set parameters minimum limits Ekelectron = 250 eV and kphoton = 100 eV
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| 162 | kmin = 100*eV;
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| 163 | Ekmin = 250*eV;
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| 164 | kcut = 100*eV;
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| 165 |
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| 166 | // Increment Theta value for surface interpolation
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| 167 | dtheta = 0.1*rad;
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| 168 |
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| 169 | // Construct Majorant Surface to 2BN cross-section
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| 170 | // (we dont need this. Pre-calculated values are used instead due to performance issues
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| 171 | // ConstructMajorantSurface();
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| 172 | }
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| 173 |
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| 174 | //
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| 175 |
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| 176 | G4Generator2BN::~G4Generator2BN()
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| 177 | {}
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| 178 |
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| 179 | //
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| 180 |
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| 181 | G4double G4Generator2BN::PolarAngle(const G4double initial_energy,
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| 182 | const G4double final_energy,
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| 183 | const G4int) // Z
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| 184 | {
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| 185 |
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| 186 | G4double theta = 0;
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| 187 |
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| 188 | G4double k = initial_energy - final_energy;
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| 189 |
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| 190 | theta = Generate2BN(initial_energy, k);
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| 191 |
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| 192 | return theta;
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| 193 | }
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| 194 | //
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| 195 |
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| 196 | G4double G4Generator2BN::CalculateFkt(G4double k, G4double theta, G4double A, G4double c) const
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| 197 | {
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| 198 | G4double Fkt_value = 0;
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| 199 | Fkt_value = A*std::pow(k,-b)*theta/(1+c*theta*theta);
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| 200 | return Fkt_value;
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| 201 | }
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| 202 |
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| 203 | G4double G4Generator2BN::Calculatedsdkdt(G4double kout, G4double theta, G4double Eel) const
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| 204 | {
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| 205 |
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| 206 | G4double dsdkdt_value = 0.;
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| 207 | G4double Z = 1;
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| 208 | // classic radius (in cm)
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| 209 | G4double r0 = 2.82E-13;
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| 210 | //squared classic radius (in barn)
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| 211 | G4double r02 = r0*r0*1.0E+24;
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| 212 |
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| 213 | // Photon energy cannot be greater than electron kinetic energy
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| 214 | if(kout > (Eel-electron_mass_c2)){
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| 215 | dsdkdt_value = 0;
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| 216 | return dsdkdt_value;
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| 217 | }
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| 218 |
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| 219 | G4double E0 = Eel/electron_mass_c2;
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| 220 | G4double k = kout/electron_mass_c2;
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| 221 | G4double E = E0 - k;
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| 222 |
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| 223 | if(E <= 1*MeV ){ // Kinematic limit at 1 MeV !!
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| 224 | dsdkdt_value = 0;
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| 225 | return dsdkdt_value;
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| 226 | }
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| 227 |
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| 228 |
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| 229 | G4double p0 = std::sqrt(E0*E0-1);
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| 230 | G4double p = std::sqrt(E*E-1);
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| 231 | G4double L = std::log((E*E0-1+p*p0)/(E*E0-1-p*p0));
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| 232 | G4double delta0 = E0 - p0*std::cos(theta);
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| 233 | G4double epsilon = std::log((E+p)/(E-p));
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| 234 | G4double Z2 = Z*Z;
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| 235 | G4double sintheta2 = std::sin(theta)*std::sin(theta);
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| 236 | G4double E02 = E0*E0;
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| 237 | G4double E2 = E*E;
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| 238 | G4double p02 = E0*E0-1;
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| 239 | G4double k2 = k*k;
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| 240 | G4double delta02 = delta0*delta0;
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| 241 | G4double delta04 = delta02* delta02;
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| 242 | G4double Q = std::sqrt(p02+k2-2*k*p0*std::cos(theta));
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| 243 | G4double Q2 = Q*Q;
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| 244 | G4double epsilonQ = std::log((Q+p)/(Q-p));
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| 245 |
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| 246 |
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| 247 | dsdkdt_value = Z2 * (r02/(8*pi*137)) * (1/k) * (p/p0) *
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| 248 | ( (8 * (sintheta2*(2*E02+1))/(p02*delta04)) -
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| 249 | ((2*(5*E02+2*E*E0+3))/(p02 * delta02)) -
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| 250 | ((2*(p02-k2))/((Q2*delta02))) +
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| 251 | ((4*E)/(p02*delta0)) +
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| 252 | (L/(p*p0))*(
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| 253 | ((4*E0*sintheta2*(3*k-p02*E))/(p02*delta04)) +
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| 254 | ((4*E02*(E02+E2))/(p02*delta02)) +
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| 255 | ((2-2*(7*E02-3*E*E0+E2))/(p02*delta02)) +
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| 256 | (2*k*(E02+E*E0-1))/((p02*delta0))
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| 257 | ) -
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| 258 | ((4*epsilon)/(p*delta0)) +
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| 259 | ((epsilonQ)/(p*Q))*
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| 260 | (4/delta02-(6*k/delta0)-(2*k*(p02-k2))/(Q2*delta0))
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| 261 | );
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| 262 |
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| 263 |
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| 264 |
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| 265 | dsdkdt_value = dsdkdt_value*std::sin(theta);
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| 266 | return dsdkdt_value;
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| 267 | }
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| 268 |
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| 269 | void G4Generator2BN::ConstructMajorantSurface()
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| 270 | {
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| 271 |
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| 272 | G4double Eel;
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| 273 | G4int vmax;
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| 274 | G4double Ek;
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| 275 | G4double k, theta, k0, theta0, thetamax;
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| 276 | G4double ds, df, dsmax, dk, dt;
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| 277 | G4double ratmin;
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| 278 | G4double ratio = 0;
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| 279 | G4double Vds, Vdf;
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| 280 | G4double A, c;
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| 281 |
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| 282 | G4cout << "**** Constructing Majorant Surface for 2BN Distribution ****" << G4endl;
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| 283 |
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| 284 | if(kcut > kmin) kmin = kcut;
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| 285 |
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| 286 | G4int i = 0;
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| 287 | // Loop on energy index
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| 288 | for(G4int index = index_min; index < index_max; index++){
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| 289 |
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| 290 | G4double fraction = index/100.;
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| 291 | Ek = std::pow(10.,fraction);
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| 292 | Eel = Ek + electron_mass_c2;
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| 293 |
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| 294 | // find x-section maximum at k=kmin
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| 295 | dsmax = 0.;
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| 296 | thetamax = 0.;
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| 297 |
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| 298 | for(theta = 0.; theta < pi; theta = theta + dtheta){
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| 299 |
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|---|
| 300 | ds = Calculatedsdkdt(kmin, theta, Eel);
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| 301 |
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|---|
| 302 | if(ds > dsmax){
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|---|
| 303 | dsmax = ds;
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|---|
| 304 | thetamax = theta;
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|---|
| 305 | }
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|---|
| 306 | }
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|---|
| 307 |
|
|---|
| 308 | // Compute surface paremeters at kmin
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|---|
| 309 | if(Ek < kmin || thetamax == 0){
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|---|
| 310 | c = 0;
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|---|
| 311 | A = 0;
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|---|
| 312 | }else{
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|---|
| 313 | c = 1/(thetamax*thetamax);
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|---|
| 314 | A = 2*std::sqrt(c)*dsmax/(std::pow(kmin,-b));
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|---|
| 315 | }
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|---|
| 316 |
|
|---|
| 317 | // look for correction factor to normalization at kmin
|
|---|
| 318 | ratmin = 1.;
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|---|
| 319 |
|
|---|
| 320 | // Volume under surfaces
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|---|
| 321 | Vds = 0.;
|
|---|
| 322 | Vdf = 0.;
|
|---|
| 323 | k0 = 0.;
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|---|
| 324 | theta0 = 0.;
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|---|
| 325 |
|
|---|
| 326 | vmax = G4int(100.*std::log10(Ek/kmin));
|
|---|
| 327 |
|
|---|
| 328 | for(G4int v = 0; v < vmax; v++){
|
|---|
| 329 | G4double fraction = (v/100.);
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|---|
| 330 | k = std::pow(10.,fraction)*kmin;
|
|---|
| 331 |
|
|---|
| 332 | for(theta = 0.; theta < pi; theta = theta + dtheta){
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|---|
| 333 | dk = k - k0;
|
|---|
| 334 | dt = theta - theta0;
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|---|
| 335 | ds = Calculatedsdkdt(k,theta, Eel);
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|---|
| 336 | Vds = Vds + ds*dk*dt;
|
|---|
| 337 | df = CalculateFkt(k,theta, A, c);
|
|---|
| 338 | Vdf = Vdf + df*dk*dt;
|
|---|
| 339 |
|
|---|
| 340 | if(ds != 0.){
|
|---|
| 341 | if(df != 0.) ratio = df/ds;
|
|---|
| 342 | }
|
|---|
| 343 |
|
|---|
| 344 | if(ratio < ratmin && ratio != 0.){
|
|---|
| 345 | ratmin = ratio;
|
|---|
| 346 | }
|
|---|
| 347 | }
|
|---|
| 348 | }
|
|---|
| 349 |
|
|---|
| 350 |
|
|---|
| 351 | // sampling efficiency
|
|---|
| 352 | Atab[i] = A/ratmin * 1.04;
|
|---|
| 353 | ctab[i] = c;
|
|---|
| 354 |
|
|---|
| 355 | // G4cout << Ek << " " << i << " " << index << " " << Atab[i] << " " << ctab[i] << " " << G4endl;
|
|---|
| 356 | i++;
|
|---|
| 357 | }
|
|---|
| 358 |
|
|---|
| 359 | }
|
|---|
| 360 |
|
|---|
| 361 | G4double G4Generator2BN::Generate2BN(G4double Ek, G4double k) const
|
|---|
| 362 | {
|
|---|
| 363 |
|
|---|
| 364 | G4double Eel;
|
|---|
| 365 | G4double kmin2;
|
|---|
| 366 | G4double kmax, t;
|
|---|
| 367 | G4double cte2;
|
|---|
| 368 | G4double y, u;
|
|---|
| 369 | G4double fk, ft;
|
|---|
| 370 | G4double ds;
|
|---|
| 371 | G4double A2;
|
|---|
| 372 | G4double A, c;
|
|---|
| 373 |
|
|---|
| 374 | G4int trials = 0;
|
|---|
| 375 | G4int index;
|
|---|
| 376 |
|
|---|
| 377 | // find table index
|
|---|
| 378 | index = G4int(std::log10(Ek)*100) - index_min;
|
|---|
| 379 | Eel = Ek + electron_mass_c2;
|
|---|
| 380 |
|
|---|
| 381 | kmax = Ek;
|
|---|
| 382 | kmin2 = kcut;
|
|---|
| 383 |
|
|---|
| 384 | c = ctab[index];
|
|---|
| 385 | A = Atab[index];
|
|---|
| 386 | if(index < index_max){
|
|---|
| 387 | A2 = Atab[index+1];
|
|---|
| 388 | if(A2 > A) A = A2;
|
|---|
| 389 | }
|
|---|
| 390 |
|
|---|
| 391 | do{
|
|---|
| 392 | // generate k accordimg to std::pow(k,-b)
|
|---|
| 393 | trials++;
|
|---|
| 394 |
|
|---|
| 395 | // normalization constant
|
|---|
| 396 | // cte1 = (1-b)/(std::pow(kmax,(1-b))-std::pow(kmin2,(1-b)));
|
|---|
| 397 | // y = G4UniformRand();
|
|---|
| 398 | // k = std::pow(((1-b)/cte1*y+std::pow(kmin2,(1-b))),(1/(1-b)));
|
|---|
| 399 |
|
|---|
| 400 | // generate theta accordimg to theta/(1+c*std::pow(theta,2)
|
|---|
| 401 | // Normalization constant
|
|---|
| 402 | cte2 = 2*c/std::log(1+c*pi2);
|
|---|
| 403 |
|
|---|
| 404 | y = G4UniformRand();
|
|---|
| 405 | t = std::sqrt((std::exp(2*c*y/cte2)-1)/c);
|
|---|
| 406 | u = G4UniformRand();
|
|---|
| 407 |
|
|---|
| 408 | // point acceptance algorithm
|
|---|
| 409 | fk = std::pow(k,-b);
|
|---|
| 410 | ft = t/(1+c*t*t);
|
|---|
| 411 | ds = Calculatedsdkdt(k,t,Eel);
|
|---|
| 412 |
|
|---|
| 413 | // violation point
|
|---|
| 414 | if(ds > (A*fk*ft)) G4cout << "WARNING IN G4Generator2BN !!!" << Ek << " " << (ds-A*fk*ft)/ds << G4endl;
|
|---|
| 415 |
|
|---|
| 416 | }while(u*A*fk*ft > ds);
|
|---|
| 417 |
|
|---|
| 418 | return t;
|
|---|
| 419 |
|
|---|
| 420 | }
|
|---|
| 421 |
|
|---|
| 422 | void G4Generator2BN::PrintGeneratorInformation() const
|
|---|
| 423 | {
|
|---|
| 424 | G4cout << "\n" << G4endl;
|
|---|
| 425 | G4cout << "Bremsstrahlung Angular Generator is 2BN Generator from 2BN Koch & Motz distribution (Rev Mod Phys 31(4), 920 (1959))" << G4endl;
|
|---|
| 426 | G4cout << "\n" << G4endl;
|
|---|
| 427 | }
|
|---|
| 428 |
|
|---|
