| Geant4 Cross Reference |
1 // 1
2 // *******************************************
3 // * License and Disclaimer
4 // *
5 // * The Geant4 software is copyright of th
6 // * the Geant4 Collaboration. It is provided
7 // * conditions of the Geant4 Software License
8 // * LICENSE and available at http://cern.ch/
9 // * include a list of copyright holders.
10 // *
11 // * Neither the authors of this software syst
12 // * institutes,nor the agencies providing fin
13 // * work make any representation or warran
14 // * regarding this software system or assum
15 // * use. Please see the license in the file
16 // * for the full disclaimer and the limitatio
17 // *
18 // * This code implementation is the result
19 // * technical work of the GEANT4 collaboratio
20 // * By using, copying, modifying or distri
21 // * any work based on the software) you ag
22 // * use in resulting scientific publicati
23 // * acceptance of all terms of the Geant4 Sof
24 // *******************************************
25 //
26 // 16.05.17 V. Grichine first implementation
27
28
29 #include "G4NeutronElectronElXsc.hh"
30 #include "G4PhysicalConstants.hh"
31 #include "G4SystemOfUnits.hh"
32 #include "G4DynamicParticle.hh"
33 #include "G4ParticleDefinition.hh"
34 #include "G4ParticleTable.hh"
35 #include "G4IonTable.hh"
36 #include "G4HadTmpUtil.hh"
37 #include "G4NistManager.hh"
38 // #include "G4Integrator.hh"
39
40 #include "G4PhysicsLogVector.hh"
41 #include "G4PhysicsTable.hh"
42
43 #include "G4Neutron.hh"
44 #include "G4Electron.hh"
45
46
47 using namespace std;
48 using namespace CLHEP;
49
50 G4NeutronElectronElXsc::G4NeutronElectronElXsc
51 : G4VCrossSectionDataSet("NuElectronCcXsc")
52 {
53 // neutron magneton squared
54
55 fM = neutron_mass_c2; // neutron mass
56 fM2 = fM*fM;
57 fme = electron_mass_c2;
58 fme2 = fme*fme;
59 fMv2 = 0.7056*GeV*GeV;
60 fee = fme;
61 fee2 = fee*fee;
62 fAm = 0.001;
63
64 fCofXsc = pi*fine_structure_const*fine_stru
65 fCofXsc *= 3.6481; // neutron Fm^2(0)
66 fCofXsc /= fM*fM;
67
68 // G4cout<<"fCofXsc = "<<fCofXsc*GeV/cm2<<"
69
70 // G4cout<<"hbarc = "<<hbarc/MeV/fermi<<" Me
71
72 fCutEnergy = 0.; // default value
73
74 fEnergyBin = 200;
75 fMinEnergy = 1.*MeV;
76 fMaxEnergy = 10000.*GeV;
77
78 fEnergyXscVector = new G4PhysicsLogVector(fM
79
80 for( G4int iTkin = 0; iTkin < fEnergyBin; iT
81
82 fBiasingFactor = 1.;
83
84 // Initialise();
85 }
86
87 G4NeutronElectronElXsc::~G4NeutronElectronElXs
88 {
89 if( fEnergyXscVector )
90 {
91 delete fEnergyXscVector;
92 fEnergyXscVector = 0;
93 }
94 }
95
96 //////////////////////////////////////////////
97 //
98 // For neutrons in the precalculated energy in
99
100 G4bool
101 G4NeutronElectronElXsc::IsElementApplicable( c
102 {
103 G4bool result = false;
104 G4String pName = aPart->GetDefinition()->Get
105 G4double Tkin = aPart->GetKineticEnergy();
106
107 if( pName == "neutron" &&
108 Tkin >= fMinEnergy &&
109 Tkin <= fMaxEnergy ) result = true;
110
111 return result;
112 }
113
114 //////////////////////////////////////////////
115
116 void G4NeutronElectronElXsc::Initialise()
117 {
118 G4int iTkin;
119 G4double Tkin, rosxsc, xsc, delta, err=1.e-5
120 const G4ThreeVector mDir = G4ThreeVector(0.,
121 const G4ParticleDefinition* pD = G4Neutron::
122 G4Material* mat = G4NistManager::Instance()-
123
124 G4DynamicParticle dP;
125
126 for( iTkin = 0; iTkin < fEnergyBin; iTkin++)
127 {
128 Tkin = fEnergyXscVector->GetLowEdgeEnergy
129 dP = G4DynamicParticle(pD, mDir, Tkin);
130 rosxsc = GetRosenbluthXsc(&dP, 1, mat);
131 fEnergyXscVector->PutValue(iTkin, rosxsc);
132 xsc= fEnergyXscVector->Value(Tkin); // xsc
133 delta = 0.5*std::abs( (rosxsc-xsc) )/(rosx
134 if(delta > err) G4cout<<Tkin/GeV<<" GeV, r
135 }
136 return;
137 }
138
139 //////////////////////////////////////////////
140
141 G4double G4NeutronElectronElXsc::
142 GetElementCrossSection(const G4DynamicParticle
143 const G4Material*)
144 {
145 G4double result = 0., Tkin;
146
147 Tkin = aPart->GetKineticEnergy();
148
149 result = fEnergyXscVector->Value(Tkin);
150
151 result *= ZZ; // incoherent sum over all e
152
153 result *= fBiasingFactor;
154
155 return result;
156 }
157
158 //////////////////////////////////////////////
159 //
160 // Integration of the Rosenbluth differential
161
162 G4double G4NeutronElectronElXsc::
163 GetRosenbluthXsc(const G4DynamicParticle* aPar
164 const G4Material*)
165 {
166 G4double result = 0., momentum;
167
168 fee = aPart->GetTotalEnergy()*fme/fM;
169 fee2 = fee*fee;
170 momentum = sqrt( fee2 - fme2 );
171 fAm = CalculateAm(momentum);
172
173 // G4Integrator<G4NeutronElectronElXsc, G4do
174
175 // result = integral.Legendre96( this, &G4Ne
176
177 result *= fCofXsc;
178
179 result *= ZZ; // incoherent sum over all e
180
181 return result;
182 }
183
184 /////////////////////////////////////////
185 //
186 // Rosenbluth relation in the neutron rest fra
187 // x = sin^2(theta/2), theta is the electron s
188 // Magnetic form factor in the dipole approxim
189
190 G4double G4NeutronElectronElXsc::XscIntegrand(
191 {
192 G4double result = 1., q2, znq2, znf, znf2, z
193
194 znq2 = 1. + 2.*fee*x/fM;
195
196 q2 = 4.*fee2*x/znq2;
197
198 znf = 1 + q2/fMv2;
199 znf2 = znf*znf;
200 znf4 = znf2*znf2;
201
202 result /= ( x + fAm )*znq2*znq2*znf4;
203
204 result *= ( 1 - x )/( 1 + q2/4./fM2 ) + 2.*x
205
206 return result;
207 }
208
209 //////////////////////////////////////////////
210 //
211 // Rosenbluth xsc in microbarn from 1*MeV to 1
212
213 const G4double G4NeutronElectronElXsc::fXscArr
214 1.52681, 1.54903, 1.57123, 1.59341, 1.61556, 1
215 1.72601, 1.74805, 1.77007, 1.79208, 1.81407, 1
216 1.92385, 1.94578, 1.96771, 1.98962, 2.01154, 2
217 2.12105, 2.14295, 2.16485, 2.18675, 2.20865, 2
218 2.31807, 2.33992, 2.36173, 2.38351, 2.40524, 2
219 2.51262, 2.53369, 2.55457, 2.57524, 2.59565, 2
220 2.69281, 2.71104, 2.72881, 2.74607, 2.76282, 2
221 2.83811, 2.85139, 2.86408, 2.87616, 2.88764, 2
222 2.93641, 2.94453, 2.95213, 2.95924, 2.96588, 2
223 2.99268, 2.9969, 3.00078, 3.00435, 3.00761, 3.
224 3.02003, 3.02185, 3.02347, 3.02491, 3.02619, 3
225 3.03049, 3.03099, 3.03139, 3.03169, 3.03191, 3
226 3.03177, 3.03152, 3.0312, 3.03081, 3.03034, 3.
227 3.02684, 3.02588, 3.02482, 3.02365, 3.02237, 3
228 3.01389, 3.01169, 3.00929, 3.00666, 3.00379, 3
229 2.98487, 2.97996, 2.97459, 2.9687, 2.96226, 2.
230 2.91965, 2.90858, 2.89649, 2.88329, 2.86889, 2
231 2.77594, 2.7526, 2.72754, 2.70071, 2.67209, 2.
232 2.50336, 2.46504, 2.42548, 2.38484, 2.34328, 2
233 2.12735, 2.08345, 2.03954, 1.99569, 1.95191, 1
234 1.7348, 1.69171, 1.64869, 1.60575, 1.56286, 1.
235 1.34877, 1.30596, 1.26314, 1.22031, 1.17746, 1
236 0.962892, 0.919908 };
237