| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer << 3 // * DISCLAIMER *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th << 5 // * The following disclaimer summarizes all the specific disclaimers *
6 // * the Geant4 Collaboration. It is provided << 6 // * of contributors to this software. The specific disclaimers,which *
7 // * conditions of the Geant4 Software License << 7 // * govern, are listed with their locations in: *
8 // * LICENSE and available at http://cern.ch/ << 8 // * http://cern.ch/geant4/license *
9 // * include a list of copyright holders. <<
10 // * 9 // * *
11 // * Neither the authors of this software syst 10 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 11 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 12 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 13 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file << 14 // * use. *
16 // * for the full disclaimer and the limitatio <<
17 // * 15 // * *
18 // * This code implementation is the result << 16 // * This code implementation is the intellectual property of the *
19 // * technical work of the GEANT4 collaboratio << 17 // * GEANT4 collaboration. *
20 // * By using, copying, modifying or distri << 18 // * By copying, distributing or modifying the Program (or any work *
21 // * any work based on the software) you ag << 19 // * based on the Program) you indicate your acceptance of this *
22 // * use in resulting scientific publicati << 20 // * statement, and all its terms. *
23 // * acceptance of all terms of the Geant4 Sof <<
24 // ******************************************* 21 // ********************************************************************
25 // 22 //
26 // 23 //
27 // ------------------------------------------- 24 // -------------------------------------------------------------------
28 // 25 //
29 // GEANT4 Class file 26 // GEANT4 Class file
30 // 27 //
31 // 28 //
32 // File name: G4Generator2BS 29 // File name: G4Generator2BS
33 // 30 //
34 // Author: Andreia Trindade (andreia@li 31 // Author: Andreia Trindade (andreia@lip.pt)
35 // Pedro Rodrigues (psilva@lip 32 // Pedro Rodrigues (psilva@lip.pt)
36 // Luis Peralta (luis@lip.p 33 // Luis Peralta (luis@lip.pt)
37 // 34 //
38 // Creation date: 2 June 2003 35 // Creation date: 2 June 2003
39 // 36 //
40 // Modifications: 37 // Modifications:
41 // 02 Jun 2003 First implementat << 38 // 02 Jun 2003 First implementation acording with new design
42 // 05 Nov 2003 MGP Fixed std namespa << 39 // 05 Nov 2003 MGP Fixed std namespace
43 // 17 Nov 2003 MGP Fixed compilation << 40 // 17 Nov 2003 MGP Fixed compilation problem on Windows
44 // 12 Oct 2010 V.Ivanchenko Moved RejectionFu <<
45 // 09 May 2011 L.Pandola Initialize privat <<
46 // 41 //
47 // Class Description: 42 // Class Description:
48 // 43 //
49 // Concrete base class for Bremsstrahlung Angu << 44 // Concrete base class for Bremsstrahlung Angular Distribution Generation - 2BS Distribution
50 // 2BS Distribution <<
51 // 45 //
52 // Class Description: End 46 // Class Description: End
53 // 47 //
54 // ------------------------------------------- 48 // -------------------------------------------------------------------
55 // 49 //
>> 50 //
56 51
57 #include "G4Generator2BS.hh" 52 #include "G4Generator2BS.hh"
58 #include "Randomize.hh" << 53 #include "Randomize.hh"
59 #include "G4PhysicalConstants.hh" << 54 //
60 #include "G4SystemOfUnits.hh" << 55
61 #include "G4Pow.hh" << 56 G4Generator2BS::G4Generator2BS(const G4String& name):G4VBremAngularDistribution(name)
62 << 57 {;}
63 G4Generator2BS::G4Generator2BS(const G4String& << 58
64 : G4VEmAngularDistribution("AngularGen2BS"), << 59 //
65 ratio1(1.),ratio2(1.),delta(0.) <<
66 { <<
67 g4pow = G4Pow::GetInstance(); <<
68 nwarn = 0; <<
69 } <<
70 60
71 G4Generator2BS::~G4Generator2BS() 61 G4Generator2BS::~G4Generator2BS()
72 {} << 62 {;}
>> 63
>> 64 //
73 65
74 G4ThreeVector& G4Generator2BS::SampleDirection << 66 G4double G4Generator2BS::PolarAngle(const G4double initial_energy,
75 G4double final_energy, << 67 const G4double final_energy,
76 G4int Z, << 68 const G4int Z)
77 const G4Material*) <<
78 { 69 {
>> 70
79 // Adapted from "Improved bremsstrahlung pho 71 // Adapted from "Improved bremsstrahlung photon angular sampling in the EGS4 code system"
80 // by Alex F. Bielajew, Rahde Mohan anc Chen 72 // by Alex F. Bielajew, Rahde Mohan anc Chen-Shou Chui, PIRS-0203
81 // Ionizing Radiation Standards 73 // Ionizing Radiation Standards
82 // Institute for National Measurement Standa 74 // Institute for National Measurement Standards
83 // National Research Council of Canada 75 // National Research Council of Canada
84 // Departement of Medical Physics, Memorial 76 // Departement of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York
85 77
86 G4double energy = dp->GetTotalEnergy(); <<
87 ratio = final_energy/energy; <<
88 ratio1 = (1 + ratio)*(1 + ratio); <<
89 ratio2 = 1 + ratio*ratio; <<
90 <<
91 G4double gamma = energy/electron_mass_c2; <<
92 G4double beta = std::sqrt((gamma - 1)*(gamm <<
93 <<
94 // VI speadup <<
95 fz = 0.00008116224*g4pow->Z13(Z)*g4pow->Z13( <<
96 <<
97 // majoranta <<
98 G4double ymax = 2*beta*(1 + beta)*gamma*gamm <<
99 G4double gMax = RejectionFunction(0.0); <<
100 gMax = std::max(gMax,RejectionFunction(ymax) <<
101 78
102 G4double y, gfun; << 79 G4double theta = 0;
>> 80
>> 81 G4double initialTotalEnergy = (initial_energy+electron_mass_c2)/electron_mass_c2;
>> 82 G4double finalTotalEnergy = (final_energy+electron_mass_c2)/electron_mass_c2;
>> 83 EnergyRatio = finalTotalEnergy/initialTotalEnergy;
>> 84 G4double gMaxEnergy = (M_PI*initialTotalEnergy)*(M_PI*initialTotalEnergy);
>> 85
>> 86 G4double Zeff = sqrt(static_cast<G4double>(Z) * (static_cast<G4double>(Z) + 1.0));
>> 87 z = (0.00008116224*(pow(Zeff,0.3333333)));
>> 88
>> 89 // Rejection arguments
>> 90 rejection_argument1 = (1.0+EnergyRatio*EnergyRatio);
>> 91 rejection_argument2 = - 2.0*EnergyRatio + 3.0*rejection_argument1;
>> 92 rejection_argument3 = ((1-EnergyRatio)/(2.0*initialTotalEnergy*EnergyRatio))*
>> 93 ((1-EnergyRatio)/(2.0*initialTotalEnergy*EnergyRatio));
>> 94
>> 95 // Calculate rejection function at 0, 1 and Emax
>> 96 G4double gfunction0 = RejectionFunction(0);
>> 97 G4double gfunction1 = RejectionFunction(1);
>> 98 G4double gfunctionEmax = RejectionFunction(gMaxEnergy);
>> 99
>> 100
>> 101 // Calculate Maximum value
>> 102 G4double gMaximum = std::max(gfunction0,gfunction1);
>> 103 gMaximum = std::max(gMaximum,gfunctionEmax);
>> 104
>> 105 G4double rand, gfunctionTest, randTest;
103 106
104 do{ 107 do{
105 G4double q = G4UniformRand(); << 108 rand = G4UniformRand();
106 y = q*ymax/(1 + ymax*(1 - q)); << 109 rand = rand/(1-rand+1.0/gMaxEnergy);
107 gfun = RejectionFunction(y); << 110 gfunctionTest = RejectionFunction(rand);
108 << 111 randTest = G4UniformRand();
109 // violation point << 112
110 if(gfun > gMax && nwarn >= 20) { << 113 }while(randTest > (gfunctionTest/gMaximum));
111 ++nwarn; << 114
112 G4cout << "### WARNING in G4Generator2BS << 115 theta = sqrt(rand)/initialTotalEnergy;
113 << " Egamma(MeV)" << (energy - final_e << 116
114 << " gMax= " << gMax << " < " << gfun << 117
115 << " results are not reliable!" << 118 return theta;
116 << G4endl; << 119 }
117 if(20 == nwarn) { << 120 //
118 G4cout << " WARNING in G4Generator2BS is c << 121
119 } << 122 G4double G4Generator2BS::RejectionFunction(G4double value) const
120 } << 123 {
121 << 124
122 } while(G4UniformRand()*gMax > gfun || y > y << 125 G4double argument = (1+value)*(1+value);
123 << 126
124 G4double cost = 1 - 2*y/ymax; << 127 G4double gfunction = (4+log(rejection_argument3+(z/argument)))*
125 G4double sint = std::sqrt((1 - cost)*(1 + co << 128 ((4*EnergyRatio*value/argument)-rejection_argument1)+rejection_argument2;
126 G4double phi = twopi*G4UniformRand(); <<
127 129
128 fLocalDirection.set(sint*std::cos(phi), sint << 130 return gfunction;
129 fLocalDirection.rotateUz(dp->GetMomentumDire <<
130 131
131 return fLocalDirection; <<
132 } 132 }
133 133
134 void G4Generator2BS::PrintGeneratorInformation 134 void G4Generator2BS::PrintGeneratorInformation() const
135 { 135 {
136 G4cout << "\n" << G4endl; 136 G4cout << "\n" << G4endl;
137 G4cout << "Bremsstrahlung Angular Generator << 137 G4cout << "Bremsstrahlung Angular Generator is 2BS Generator from 2BS Koch & Motz distribution (Rev Mod Phys 31(4), 920 (1959))" << G4endl;
138 << "from 2BS Koch & Motz distribution (Rev <<
139 G4cout << "Sampling algorithm adapted from P 138 G4cout << "Sampling algorithm adapted from PIRS-0203" << G4endl;
140 G4cout << "\n" << G4endl; 139 G4cout << "\n" << G4endl;
141 } 140 }
142 141
143 142