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25 //
26 // G4eSingleCoulombScatteringModel.cc
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class header file
30 //
31 // File name: G4eSingleCoulombScatteringModel
32 //
33 // Author: Cristina Consolandi
34 //
35 // Creation date: 20.10.2012
36 //
37 // Class Description:
38 // Single Scattering model for electron-nuclei interaction.
39 // Suitable for high energy electrons and low scattering angles.
40 //
41 //
42 // Reference:
43 // M.J. Boschini et al. "Non Ionizing Energy Loss induced by Electrons
44 // in the Space Environment" Proc. of the 13th International Conference
45 // on Particle Physics and Advanced Technology
46 //
47 // (13th ICPPAT, Como 3-7/10/2011), World Scientific (Singapore).
48 // Available at: http://arxiv.org/abs/1111.4042v4
49 //
50 //
51 // -------------------------------------------------------------------
52 //
53 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
54
55
56 #include "G4eSingleCoulombScatteringModel.hh"
57 #include "G4PhysicalConstants.hh"
58 #include "G4SystemOfUnits.hh"
59 #include "Randomize.hh"
60 #include "G4ParticleChangeForGamma.hh"
61 #include "G4Proton.hh"
62 #include "G4ProductionCutsTable.hh"
63 #include "G4NucleiProperties.hh"
64 #include "G4NistManager.hh"
65 #include "G4ParticleTable.hh"
66 #include "G4IonTable.hh"
67
68 #include "G4UnitsTable.hh"
69 #include "G4EmParameters.hh"
70
71 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
72
73 using namespace std;
74
75 G4eSingleCoulombScatteringModel::G4eSingleCoulombScatteringModel(const G4String& nam)
76 : G4VEmModel(nam),
77 cosThetaMin(1.0)
78 {
79 fNistManager = G4NistManager::Instance();
80 theIonTable = G4ParticleTable::GetParticleTable()->GetIonTable();
81 fParticleChange = nullptr;
82
83 pCuts=nullptr;
84 currentMaterial = nullptr;
85 currentElement = nullptr;
86 currentCouple = nullptr;
87
88 lowEnergyLimit = 0*keV;
89 recoilThreshold = 0.*eV;
90 XSectionModel = 1;
91 FormFactor = 0;
92 particle = nullptr;
93 mass=0.0;
94 currentMaterialIndex = -1;
95
96 Mottcross = new G4ScreeningMottCrossSection();
97 //G4cout <<"## G4eSingleCoulombScatteringModel: " << this << " " << Mottcross << G4endl;
98 }
99
100 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
101
102 G4eSingleCoulombScatteringModel::~G4eSingleCoulombScatteringModel()
103 {
104 //G4cout <<"## G4eSingleCoulombScatteringModel: delete " << this << " " << Mottcross << G4endl;
105 delete Mottcross;
106 }
107
108 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
109
110 void G4eSingleCoulombScatteringModel::Initialise(const G4ParticleDefinition* p,
111 const G4DataVector& cuts)
112 {
113 G4EmParameters* param = G4EmParameters::Instance();
114
115 SetupParticle(p);
116 currentCouple = nullptr;
117 currentMaterialIndex = -1;
118 //cosThetaMin = cos(PolarAngleLimit());
119 Mottcross->Initialise(p,cosThetaMin);
120
121 pCuts = &cuts;
122 //G4ProductionCutsTable::GetProductionCutsTable()->GetEnergyCutsVector(3);
123
124 /*
125 G4cout << "!!! G4eSingleCoulombScatteringModel::Initialise for "
126 << part->GetParticleName() << " cos(TetMin)= " << cosThetaMin
127 << " cos(TetMax)= " << cosThetaMax <<G4endl;
128 G4cout << "cut= " << (*pCuts)[0] << " cut1= " << (*pCuts)[1] << G4endl;
129 */
130
131 if(!fParticleChange) {
132 fParticleChange = GetParticleChangeForGamma();
133 }
134
135 if(IsMaster()) {
136 InitialiseElementSelectors(p,cuts);
137 }
138
139 FormFactor=param->NuclearFormfactorType();
140
141 //G4cout<<"NUCLEAR FORM FACTOR: "<<FormFactor<<G4endl;
142 }
143
144 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
145
146 void
147 G4eSingleCoulombScatteringModel::InitialiseLocal(const G4ParticleDefinition*,
148 G4VEmModel* masterModel)
149 {
150 SetElementSelectors(masterModel->GetElementSelectors());
151 }
152
153 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
154
155 void G4eSingleCoulombScatteringModel::SetXSectionModel(const G4String& model)
156 {
157 if(model == "Fast" || model == "fast") { XSectionModel=1; }
158 else if(model == "Precise" || model == "precise") { XSectionModel=0; }
159 else {
160 G4cout<<"G4eSingleCoulombScatteringModel WARNING: "<<model
161 <<" is not a valid model name"<<G4endl;
162 }
163 }
164
165 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
166
167 G4double G4eSingleCoulombScatteringModel::ComputeCrossSectionPerAtom(
168 const G4ParticleDefinition* p,
169 G4double kinEnergy,
170 G4double Z,
171 G4double ,
172 G4double,
173 G4double )
174 {
175 SetupParticle(p);
176
177 G4double cross =0.0;
178 if(kinEnergy < lowEnergyLimit) return cross;
179
180 DefineMaterial(CurrentCouple());
181
182 //Total Cross section
183 Mottcross->SetupKinematic(kinEnergy, Z);
184 cross = Mottcross->NuclearCrossSection(FormFactor,XSectionModel);
185
186 //cout<< "Compute Cross Section....cross "<<G4BestUnit(cross,"Surface") << " cm2 "<< cross/cm2 <<" Z: "<<Z<<" kinEnergy: "<<kinEnergy<<endl;
187
188 //G4cout<<"Energy: "<<kinEnergy/MeV<<" Total Cross: "<<cross<<G4endl;
189 return cross;
190 }
191
192 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
193
194 void G4eSingleCoulombScatteringModel::SampleSecondaries(
195 std::vector<G4DynamicParticle*>* fvect,
196 const G4MaterialCutsCouple* couple,
197 const G4DynamicParticle* dp,
198 G4double cutEnergy,
199 G4double)
200 {
201 G4double kinEnergy = dp->GetKineticEnergy();
202 //cout<<"--- kinEnergy "<<kinEnergy<<endl;
203
204 if(kinEnergy < lowEnergyLimit) return;
205
206 DefineMaterial(couple);
207 SetupParticle(dp->GetDefinition());
208
209 // Choose nucleus
210 //last two :cutEnergy= min e kinEnergy=max
211 currentElement = SelectTargetAtom(couple, particle, kinEnergy,
212 dp->GetLogKineticEnergy(), cutEnergy, kinEnergy);
213 G4int iz = currentElement->GetZasInt();
214 G4int ia = SelectIsotopeNumber(currentElement);
215 G4double mass2 = G4NucleiProperties::GetNuclearMass(ia, iz);
216
217 //G4cout<<"..Z: "<<Z<<" ..iz: "<<iz<<" ..ia: "<<ia<<" ..mass2: "<<mass2<<G4endl;
218
219 Mottcross->SetupKinematic(kinEnergy, iz);
220 G4double cross= Mottcross->NuclearCrossSection(FormFactor,XSectionModel);
221 if(cross == 0.0) { return; }
222 //cout<< "Energy: "<<kinEnergy/MeV<<" Z: "<<Z<<"....cross "<<G4BestUnit(cross,"Surface") << " cm2 "<< cross/cm2 <<endl;
223
224 G4double z1 = Mottcross->GetScatteringAngle(FormFactor,XSectionModel);
225 G4double sint = sin(z1);
226 G4double cost = cos(z1);
227 G4double phi = twopi* G4UniformRand();
228
229 // kinematics in the Lab system
230 G4double ptot = sqrt(kinEnergy*(kinEnergy + 2.0*mass));
231 G4double e1 = mass + kinEnergy;
232
233 // Lab. system kinematics along projectile direction
234 G4LorentzVector v0 = G4LorentzVector(0, 0, ptot, e1+mass2);
235 G4LorentzVector v1 = G4LorentzVector(0, 0, ptot, e1);
236 G4ThreeVector bst = v0.boostVector();
237 v1.boost(-bst);
238 // CM projectile
239 G4double momCM = v1.pz();
240
241 // Momentum after scattering of incident particle
242 v1.setX(momCM*sint*cos(phi));
243 v1.setY(momCM*sint*sin(phi));
244 v1.setZ(momCM*cost);
245
246 // CM--->Lab
247 v1.boost(bst);
248
249 // Rotate to global system
250 G4ThreeVector dir = dp->GetMomentumDirection();
251 G4ThreeVector newDirection = v1.vect().unit();
252 newDirection.rotateUz(dir);
253
254 fParticleChange->ProposeMomentumDirection(newDirection);
255
256 // recoil
257 v0 -= v1;
258 G4double trec = std::max(v0.e() - mass2, 0.0);
259 G4double edep = 0.0;
260
261 G4double tcut = recoilThreshold;
262
263 //G4cout<<" Energy Transfered: "<<trec/eV<<G4endl;
264
265 if(pCuts) {
266 tcut= std::max(tcut,(*pCuts)[currentMaterialIndex]);
267 //G4cout<<"Cuts: "<<(*pCuts)[currentMaterialIndex]/eV<<" eV"<<G4endl;
268 //G4cout<<"Threshold: "<<tcut/eV<<" eV"<<G4endl;
269 }
270
271 if(trec > tcut) {
272 G4ParticleDefinition* ion = theIonTable->GetIon(iz, ia, 0);
273 newDirection = v0.vect().unit();
274 newDirection.rotateUz(dir);
275 auto newdp = new G4DynamicParticle(ion, newDirection, trec);
276 fvect->push_back(newdp);
277 } else if(trec > 0.0) {
278 edep = trec;
279 fParticleChange->ProposeNonIonizingEnergyDeposit(edep);
280 }
281
282 // finelize primary energy and energy balance
283 G4double finalT = v1.e() - mass;
284 //G4cout<<"Final Energy: "<<finalT/eV<<G4endl;
285 if(finalT <= lowEnergyLimit) {
286 edep += finalT;
287 finalT = 0.0;
288 }
289 edep = std::max(edep, 0.0);
290 fParticleChange->SetProposedKineticEnergy(finalT);
291 fParticleChange->ProposeLocalEnergyDeposit(edep);
292
293 }
294
295 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
296