| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4CoulombScattering
33 //
34 // Author: Vladimir Ivanchenko
35 //
36 // Creation date: 22.08.2004
37 //
38 // Modifications:
39 // 01.08.06 V.Ivanchenko add choice between G4eCoulombScatteringModel and
40 // G4CoulombScatteringModel
41 //
42
43 //
44 // -------------------------------------------------------------------
45 //
46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
47 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
48
49 #include "G4CoulombScattering.hh"
50 #include "G4SystemOfUnits.hh"
51 #include "G4eCoulombScatteringModel.hh"
52 #include "G4IonCoulombScatteringModel.hh"
53 #include "G4Proton.hh"
54 #include "G4EmParameters.hh"
55
56 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
57
58 G4CoulombScattering::G4CoulombScattering(const G4String& nam, G4bool comb)
59 : G4VEmProcess(nam),
60 q2Max(CLHEP::TeV*CLHEP::TeV),
61 isCombined(comb)
62 {
63 SetBuildTableFlag(true);
64 SetStartFromNullFlag(false);
65 SetSplineFlag(false);
66 SetCrossSectionType(fEmOnePeak);
67 SetSecondaryParticle(G4Proton::Proton());
68 SetProcessSubType(fCoulombScattering);
69 }
70
71 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
72
73 G4CoulombScattering::G4CoulombScattering(const G4String& nam)
74 : G4CoulombScattering(nam, true)
75 {}
76
77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
78
79 G4CoulombScattering::G4CoulombScattering(G4bool comb)
80 : G4CoulombScattering("CoulombScat", comb)
81 {}
82
83 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
84
85 G4CoulombScattering::~G4CoulombScattering() = default;
86
87 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
88
89 G4bool G4CoulombScattering::IsApplicable(const G4ParticleDefinition& p)
90 {
91 return (p.GetPDGCharge() != 0.0);
92 }
93
94 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
95
96 void G4CoulombScattering::InitialiseProcess(const G4ParticleDefinition* p)
97 {
98 // second initialisation not allowed for the time being
99 // this means that polar angle limit change will not be appled
100 // after first initialisation
101 if(isInitialised) { return; }
102
103 G4EmParameters* param = G4EmParameters::Instance();
104 G4double a = param->FactorForAngleLimit()*CLHEP::hbarc/CLHEP::fermi;
105 q2Max = 0.5*a*a;
106 G4double theta = param->MscThetaLimit();
107
108 // restricted or non-restricted cross section table
109 if(isCombined) {
110 if(theta == CLHEP::pi) {
111 // for restriced single scattering change cross section shape
112 SetCrossSectionType(fEmIncreasing);
113 SetStartFromNullFlag(true);
114 }
115 } else {
116 SetSplineFlag(true);
117 SetCrossSectionType(fEmDecreasing);
118 }
119 isInitialised = true;
120 G4double mass = p->GetPDGMass();
121 G4String name = p->GetParticleName();
122
123 G4bool ion = false;
124 if (mass > CLHEP::GeV || p->GetParticleType() == "nucleus") {
125 SetBuildTableFlag(false);
126 ion = true;
127 if(name != "GenericIon") { SetVerboseLevel(0); }
128 } else {
129 if(name != "e-" && name != "e+" &&
130 name != "mu+" && name != "mu-" && name != "pi+" &&
131 name != "kaon+" && name != "proton" ) { SetVerboseLevel(0); }
132 }
133 /*
134 G4cout << "### G4CoulombScattering::InitialiseProcess: "
135 << p->GetParticleName()
136 << " Emin(MeV)= " << MinKinEnergy()/MeV
137 << " Emax(TeV)= " << MaxKinEnergy()/TeV
138 << " nbins= " << LambdaBinning()
139 << " theta= " << theta
140 << " mass(MeV)= " << mass
141 << " isCombined=" << isCombined
142 << " ion=" << ion
143 << G4endl;
144 */
145 if(nullptr == EmModel(0)) {
146 if(ion) { SetEmModel(new G4IonCoulombScatteringModel()); }
147 else { SetEmModel(new G4eCoulombScatteringModel(isCombined)); }
148 }
149 G4VEmModel* model = EmModel(0);
150 G4double emin = std::max(param->MinKinEnergy(),model->LowEnergyLimit());
151 G4double emax = std::min(param->MaxKinEnergy(),model->HighEnergyLimit());
152 model->SetPolarAngleLimit(theta);
153 model->SetLowEnergyLimit(emin);
154 model->SetHighEnergyLimit(emax);
155 AddEmModel(1, model);
156 }
157
158 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
159
160 G4double G4CoulombScattering::MinPrimaryEnergy(const G4ParticleDefinition* part,
161 const G4Material* mat)
162 {
163 // Pure Coulomb scattering
164 G4double emin = 0.0;
165
166 // Coulomb scattering combined with multiple or hadronic scattering
167 G4double theta = G4EmParameters::Instance()->MscThetaLimit();
168
169 if(0.0 < theta) {
170 G4double p2 = q2Max*mat->GetIonisation()->GetInvA23()/(1.0 - std::cos(theta));
171 G4double mass = part->GetPDGMass();
172 emin = p2/(std::sqrt(p2 + mass*mass) + mass);
173 }
174
175 return emin;
176 }
177
178 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
179
180 void G4CoulombScattering::StreamProcessInfo(std::ostream& outFile) const
181 {
182 G4double tetmin = G4EmParameters::Instance()->MscThetaLimit()/CLHEP::degree;
183 outFile << " ";
184 if(tetmin > 179.) { outFile << "ThetaMin(p)"; }
185 else { outFile << tetmin; }
186 outFile << " < Theta(degree) < 180";
187
188 if(q2Max < DBL_MAX) {
189 outFile << ", pLimit(GeV^1)= " << std::sqrt(q2Max)/GeV;
190 }
191 outFile << G4endl;
192 }
193
194 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
195
196 void G4CoulombScattering::ProcessDescription(std::ostream& out) const
197 {
198 out <<
199 " Coulomb scattering. Simulation of elastic scattering\n" <<
200 " events individually. May be used in combination with multiple\n" <<
201 " scattering, where Coulomb scattering is used for hard (large angle)\n" <<
202 " collisions and multiple scattering for soft collisions.";
203 G4VEmProcess::ProcessDescription(out);
204 }
205
206 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
207