source: trunk/source/processes/electromagnetic/standard/include/G4WentzelOKandVIxSection.hh @ 1316

Last change on this file since 1316 was 1316, checked in by garnier, 14 years ago

update geant4-09-04-beta-cand-01 interfaces-V09-03-09 vis-V09-03-08
File size: 7.5 KB
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25//
26// $Id: G4WentzelOKandVIxSection.hh,v 1.5 2010/06/01 11:13:31 vnivanch Exp $
27// GEANT4 tag $Name: geant4-09-04-beta-cand-01 $
28//
29// -------------------------------------------------------------------
30//
31//
32// GEANT4 Class header file
33//
34//
35// File name:     G4WentzelOKandVIxSection
36//
37// Authors:       V.Ivanchenko and O.Kadri
38//
39// Creation date: 21.05.2010
40//
41// Modifications:
42//
43//
44// Class Description:
45//
46// Implementation of the computation of total and transport cross sections,
47// sample scattering angle for the single scattering case.
48// to be used by single and multiple scattering models. References:
49// 1) G.Wentzel, Z. Phys. 40 (1927) 590.
50// 2) J.M. Fernandez-Varea et al., NIM B73 (1993) 447.
51//
52// -------------------------------------------------------------------
53//
54
55#ifndef G4WentzelOKandVIxSection_h
56#define G4WentzelOKandVIxSection_h 1
57
58//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
59
60#include "globals.hh"
61#include "G4Material.hh"
62#include "G4Element.hh"
63#include "G4ElementVector.hh"
64#include "G4NistManager.hh"
65#include "G4ThreeVector.hh"
66#include "G4Pow.hh"
67
68class G4ParticleDefinition;
69
70//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
71
72class G4WentzelOKandVIxSection 
73{
74
75public:
76
77  G4WentzelOKandVIxSection();
78
79  virtual ~G4WentzelOKandVIxSection();
80
81  void Initialise(const G4ParticleDefinition*, G4double CosThetaLim);
82
83  void SetupParticle(const G4ParticleDefinition*);
84
85  // return cos(ThetaMax) for msc and cos(thetaMin) for single scattering
86  // cut = DBL_MAX means no scattering off electrons
87  G4double SetupTarget(G4int Z, G4double cut = DBL_MAX);
88
89  G4double ComputeTransportCrossSectionPerAtom(G4double CosThetaMax);
90 
91  G4ThreeVector SampleSingleScattering(G4double CosThetaMin,
92                                       G4double CosThetaMax,
93                                       G4double elecRatio = 0.0);
94
95  inline G4double ComputeNuclearCrossSection(G4double CosThetaMin,
96                                             G4double CosThetaMax);
97 
98  inline G4double ComputeElectronCrossSection(G4double CosThetaMin,
99                                              G4double CosThetaMax);
100 
101  inline G4double SetupKinematic(G4double kinEnergy, const G4Material* mat);
102 
103  inline void SetTargetMass(G4double value);
104
105  inline void SetRelativisticMass(G4double value);
106
107  inline G4double GetMomentumSquare() const;
108
109  inline G4double GetCosThetaNuc() const;
110
111  inline G4double GetCosThetaElec() const;
112
113private:
114
115  void ComputeMaxElectronScattering(G4double cut);
116
117  //  hide assignment operator
118  G4WentzelOKandVIxSection & operator=(const  G4WentzelOKandVIxSection &right);
119  G4WentzelOKandVIxSection(const  G4WentzelOKandVIxSection&);
120
121  const G4ParticleDefinition* theProton;
122  const G4ParticleDefinition* theElectron;
123  const G4ParticleDefinition* thePositron;
124  const G4Material* currentMaterial;
125
126  G4NistManager*  fNistManager;
127  G4Pow*          fG4pow;
128
129  G4double numlimit;
130
131  G4double elecXSRatio;
132
133  // integer parameters
134  G4int    nwarnings;
135  G4int    nwarnlimit;
136
137  // single scattering parameters
138  G4double coeff;
139  G4double cosTetMaxElec;
140  G4double cosTetMaxNuc;
141  G4double cosThetaMax;
142  G4double alpha2;
143
144  // projectile
145  const G4ParticleDefinition* particle;
146
147  G4double chargeSquare;
148  G4double charge3;
149  G4double spin;
150  G4double mass;
151  G4double tkin;
152  G4double mom2;
153  G4double invbeta2;
154  G4double kinFactor;
155  G4double etag;
156  G4double ecut;
157  G4double lowEnergyLimit;
158
159  // target
160  G4int    targetZ;
161  G4double targetMass;
162  G4double screenZ;
163  G4double formfactA;
164  G4double factorA2;
165  G4double factB;
166  G4double factD;
167
168  static G4double ScreenRSquare[100];
169  static G4double FormFactor[100];
170};
171
172//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
173
174inline G4double
175G4WentzelOKandVIxSection::SetupKinematic(G4double ekin, const G4Material* mat)
176{
177  if(ekin != tkin || mat != currentMaterial) { 
178    currentMaterial = mat;
179    tkin  = ekin;
180    mom2  = tkin*(tkin + 2.0*mass);
181    invbeta2 = 1.0 +  mass*mass/mom2;
182    factB = spin/invbeta2;
183    cosTetMaxNuc = cosThetaMax;
184    if(std::fabs(cosThetaMax) < 1.0) {
185      cosTetMaxNuc = 
186        std::max(cosThetaMax,1.-factorA2*mat->GetIonisation()->GetInvA23()/mom2);
187    }
188  } 
189  return cosTetMaxNuc;
190}
191
192//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
193
194inline void G4WentzelOKandVIxSection::SetTargetMass(G4double value)
195{
196  targetMass = value;
197  factD = sqrt(mom2)/value;
198}
199
200//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
201
202inline void G4WentzelOKandVIxSection::SetRelativisticMass(G4double value)
203{
204  mass = value;
205}
206
207//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
208
209inline G4double G4WentzelOKandVIxSection::GetMomentumSquare() const
210{
211  return mom2;
212}
213
214//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
215
216inline G4double G4WentzelOKandVIxSection::GetCosThetaNuc() const
217{
218  return cosTetMaxNuc;
219}
220
221//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
222
223inline G4double G4WentzelOKandVIxSection::GetCosThetaElec() const
224{
225  return cosTetMaxElec;
226}
227
228//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
229
230inline G4double
231G4WentzelOKandVIxSection::ComputeNuclearCrossSection(G4double cosTMin,
232                                                     G4double cosTMax)
233{
234  G4double xsec = 0.0;
235  if(cosTMax < cosTMin) {
236    xsec = targetZ*kinFactor*(cosTMin - cosTMax)/
237      ((1.0 - cosTMin + screenZ)*(1.0 - cosTMax + screenZ));
238  }
239  return xsec;
240}
241
242//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
243
244inline G4double
245G4WentzelOKandVIxSection::ComputeElectronCrossSection(G4double cosTMin,
246                                                      G4double cosTMax)
247{
248  G4double xsec = 0.0;
249  G4double cost1 = std::max(cosTMin,cosTetMaxElec);
250  G4double cost2 = std::max(cosTMax,cosTetMaxElec);
251  if(cost1 > cost2) {
252    xsec = kinFactor*(cost1 - cost2)/((1.0 - cost1 + screenZ)*(1.0 - cost2 + screenZ));
253  }
254  return xsec;
255}
256//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
257
258#endif
259
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