source: trunk/source/processes/electromagnetic/standard/include/G4eCoulombScatteringModel.hh@ 1314

Last change on this file since 1314 was 1228, checked in by garnier, 16 years ago

update geant4.9.3 tag
File size: 8.5 KB
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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// $Id: G4eCoulombScatteringModel.hh,v 1.49 2009/10/10 15:16:57 vnivanch Exp $
27// GEANT4 tag $Name: geant4-09-03 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class header file
32//
33//
34// File name: G4eCoulombScatteringModel
35//
36// Author: Vladimir Ivanchenko
37//
38// Creation date: 19.02.2006
39//
40// Modifications:
41// 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the
42// logic of building - only elements from G4ElementTable
43// 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim
44// 19.08.06 V.Ivanchenko add inline function ScreeningParameter and
45// make some members protected
46// 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e-
47// 09.06.08 V.Ivanchenko add SelectIsotope and sampling of the recoil ion
48// 17.06.09 C.Consoalndi modified SetupTarget method - remove kinFactor
49//
50//
51// Class Description:
52//
53// Implementation of eCoulombScattering of pointlike charge particle
54// on Atomic Nucleus for interval of scattering anles in Lab system
55// thetaMin - ThetaMax, nucleus recoil is neglected.
56// The model based on analysis of J.M.Fernandez-Varea et al.
57// NIM B73(1993)447 originated from G.Wentzel Z.Phys. 40(1927)590 with
58// screening parameter from H.A.Bethe Phys. Rev. 89 (1953) 1256.
59//
60
61// -------------------------------------------------------------------
62//
63
64#ifndef G4eCoulombScatteringModel_h
65#define G4eCoulombScatteringModel_h 1
66
67#include "G4VEmModel.hh"
68#include "G4PhysicsTable.hh"
69#include "globals.hh"
70#include "G4NistManager.hh"
71#include <vector>
72
73class G4ParticleChangeForGamma;
74class G4ParticleDefinition;
75
76class G4eCoulombScatteringModel : public G4VEmModel
77{
78
79public:
80
81 G4eCoulombScatteringModel(const G4String& nam = "eCoulombScattering");
82
83 virtual ~G4eCoulombScatteringModel();
84
85 virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&);
86
87 virtual G4double ComputeCrossSectionPerAtom(
88 const G4ParticleDefinition*,
89 G4double kinEnergy,
90 G4double Z,
91 G4double A,
92 G4double cut,
93 G4double emax);
94
95 virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*,
96 const G4MaterialCutsCouple*,
97 const G4DynamicParticle*,
98 G4double tmin,
99 G4double maxEnergy);
100
101 inline void SetRecoilThreshold(G4double eth);
102
103protected:
104
105 G4double CrossSectionPerAtom();
106
107 G4double SampleCosineTheta();
108
109 inline void DefineMaterial(const G4MaterialCutsCouple*);
110
111 inline void SetupParticle(const G4ParticleDefinition*);
112
113 inline void SetupKinematic(G4double kinEnergy, G4double cut);
114
115 inline void SetupTarget(G4double Z, G4double kinEnergy);
116
117private:
118
119 void ComputeMaxElectronScattering(G4double cut);
120
121 // hide assignment operator
122 G4eCoulombScatteringModel & operator=(const G4eCoulombScatteringModel &right);
123 G4eCoulombScatteringModel(const G4eCoulombScatteringModel&);
124
125protected:
126
127 const G4ParticleDefinition* theProton;
128 const G4ParticleDefinition* theElectron;
129 const G4ParticleDefinition* thePositron;
130
131 G4ParticleTable* theParticleTable;
132 G4ParticleChangeForGamma* fParticleChange;
133 G4NistManager* fNistManager;
134
135 const std::vector<G4double>* pCuts;
136
137 const G4MaterialCutsCouple* currentCouple;
138 const G4Material* currentMaterial;
139 const G4Element* currentElement;
140 G4int currentMaterialIndex;
141
142 G4double coeff;
143 G4double cosThetaMin;
144 G4double cosThetaMax;
145 G4double cosTetMinNuc;
146 G4double cosTetMaxNuc;
147 G4double cosTetMaxNuc2;
148 G4double cosTetMaxElec;
149 G4double cosTetMaxElec2;
150 G4double q2Limit;
151 G4double recoilThreshold;
152 G4double elecXSection;
153 G4double nucXSection;
154 G4double ecut;
155
156 // projectile
157 const G4ParticleDefinition* particle;
158
159 G4double chargeSquare;
160 G4double spin;
161 G4double mass;
162 G4double tkin;
163 G4double mom2;
164 G4double invbeta2;
165 G4double etag;
166 G4double lowEnergyLimit;
167
168 // target
169 G4double targetZ;
170 G4double targetMass;
171 G4double screenZ;
172 G4double formfactA;
173 G4int idxelm;
174 G4int iz;
175
176private:
177
178 G4double alpha2;
179 G4double faclim;
180
181 static G4double ScreenRSquare[100];
182 static G4double FormFactor[100];
183
184 G4bool isInitialised;
185};
186
187//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
188
189inline
190void G4eCoulombScatteringModel::DefineMaterial(const G4MaterialCutsCouple* cup)
191{
192 if(cup != currentCouple) {
193 currentCouple = cup;
194 currentMaterial = cup->GetMaterial();
195 currentMaterialIndex = currentCouple->GetIndex();
196 }
197}
198
199//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
200
201inline
202void G4eCoulombScatteringModel::SetupParticle(const G4ParticleDefinition* p)
203{
204 // Initialise mass and charge
205 if(p != particle) {
206 particle = p;
207 mass = particle->GetPDGMass();
208 spin = particle->GetPDGSpin();
209 G4double q = particle->GetPDGCharge()/eplus;
210 chargeSquare = q*q;
211 tkin = 0.0;
212 }
213}
214
215//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
216
217inline void G4eCoulombScatteringModel::SetupKinematic(G4double ekin,
218 G4double cut)
219{
220 if(ekin != tkin || ecut != cut) {
221 tkin = ekin;
222 mom2 = tkin*(tkin + 2.0*mass);
223 invbeta2 = 1.0 + mass*mass/mom2;
224 cosTetMinNuc = cosThetaMin;
225 cosTetMaxNuc = cosThetaMax;
226 if(mass < MeV && cosThetaMin < 1.0 && ekin <= 10.*cut) {
227 cosTetMinNuc = ekin*(cosThetaMin + 1.0)/(10.*cut) - 1.0;
228 }
229 ComputeMaxElectronScattering(cut);
230 }
231}
232
233//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
234
235inline void G4eCoulombScatteringModel::SetupTarget(G4double Z, G4double e)
236{
237 if(Z != targetZ || e != etag) {
238 etag = e;
239 targetZ = Z;
240 iz= G4int(Z);
241 if(iz > 99) iz = 99;
242 targetMass = fNistManager->GetAtomicMassAmu(iz)*amu_c2;
243 screenZ = ScreenRSquare[iz]/mom2;
244 screenZ *=(1.13 + std::min(1.0,3.76*Z*Z*invbeta2*alpha2));
245 if(mass > MeV) { screenZ *= 2.0; }
246 formfactA = FormFactor[iz]*mom2;
247 cosTetMaxNuc2 = cosTetMaxNuc;
248 if(1 == iz && particle == theProton && cosTetMaxNuc2 < 0.0) {
249 cosTetMaxNuc2 = 0.0;
250 }
251 cosTetMaxElec2 = cosTetMaxElec;
252 }
253}
254
255//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
256
257inline void G4eCoulombScatteringModel::SetRecoilThreshold(G4double eth)
258{
259 recoilThreshold = eth;
260}
261
262//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
263
264#endif
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