source: trunk/source/processes/electromagnetic/standard/include/G4eBremsstrahlungRelModel.hh @ 991

Last change on this file since 991 was 991, checked in by garnier, 15 years ago

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26// $Id: G4eBremsstrahlungRelModel.hh,v 1.10 2008/11/14 09:25:19 vnivanch Exp $
27// GEANT4 tag $Name: geant4-09-02 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class header file
32//
33//
34// File name:     G4eBremsstrahlungRelModel
35//                extention of standard G4eBremsstrahlungModel
36//
37// Author:        Andreas Schaelicke
38//
39// Creation date: 28.03.2008
40//
41// Modifications:
42//
43//
44// Class Description:
45//
46// Implementation of energy loss for gamma emission by electrons and
47// positrons including an improved version of the LPM effect
48
49// -------------------------------------------------------------------
50//
51
52#ifndef G4eBremsstrahlungRelModel_h
53#define G4eBremsstrahlungRelModel_h 1
54
55#include "G4VEmModel.hh"
56#include "G4NistManager.hh"
57
58class G4ParticleChangeForLoss;
59class G4PhysicsVector;
60
61class G4eBremsstrahlungRelModel : public G4VEmModel
62{
63
64public:
65
66  G4eBremsstrahlungRelModel(const G4ParticleDefinition* p = 0, 
67                            const G4String& nam = "eBremRel");
68
69  virtual ~G4eBremsstrahlungRelModel();
70
71  virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&);
72
73  G4double MinEnergyCut(const G4ParticleDefinition*, 
74                        const G4MaterialCutsCouple*);
75
76  virtual G4double ComputeDEDXPerVolume(const G4Material*,
77                                        const G4ParticleDefinition*,
78                                        G4double kineticEnergy,
79                                        G4double cutEnergy);
80                                       
81  virtual G4double ComputeCrossSectionPerAtom(const G4ParticleDefinition*,
82                                              G4double tkin, 
83                                              G4double Z,   G4double,
84                                              G4double cutEnergy,
85                                              G4double maxEnergy = DBL_MAX);
86 
87  virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*,
88                                 const G4MaterialCutsCouple*,
89                                 const G4DynamicParticle*,
90                                 G4double cutEnergy,
91                                 G4double maxEnergy);
92
93  virtual void SetupForMaterial(const G4ParticleDefinition*,
94                                const G4Material*,G4double);
95
96  inline void SetLPMconstant(G4double val);
97  inline G4double LPMconstant() const;
98
99protected:
100
101  inline G4double MaxSecondaryEnergy(const G4ParticleDefinition*,
102                                     G4double kineticEnergy);
103
104private:
105
106  void InitialiseConstants();
107
108  void CalcLPMFunctions(G4double gammaEnergy);
109
110  G4double ComputeBremLoss(G4double cutEnergy);
111
112  G4double ComputeXSectionPerAtom(G4double cutEnergy);
113
114  G4double ComputeDXSectionPerAtom(G4double gammaEnergy);
115
116  G4double ComputeRelDXSectionPerAtom(G4double gammaEnergy);
117
118  void SetParticle(const G4ParticleDefinition* p);
119
120  // * fast inline functions *
121  inline void SetCurrentElement(const G4double);
122
123  inline G4double Phi1(G4double,G4double);
124  inline G4double Phi1M2(G4double,G4double);
125  inline G4double Psi1(G4double,G4double);
126  inline G4double Psi1M2(G4double,G4double);
127
128  // hide assignment operator
129  G4eBremsstrahlungRelModel & operator=(const  G4eBremsstrahlungRelModel &right);
130  G4eBremsstrahlungRelModel(const  G4eBremsstrahlungRelModel&);
131
132protected:
133
134  G4NistManager*              nist;
135  const G4ParticleDefinition* particle;
136  G4ParticleDefinition*       theGamma;
137  G4ParticleChangeForLoss*    fParticleChange;
138
139  static const G4double xgi[8], wgi[8];
140  static const G4double Fel_light[5];
141  static const G4double Finel_light[5];
142
143  G4double minThreshold;
144
145  // cash
146  G4double particleMass;
147  G4double kinEnergy;
148  G4double totalEnergy;
149  G4double currentZ;
150  G4double z13, z23, lnZ;
151  G4double Fel, Finel, fCoulomb, fMax; 
152  G4double densityFactor;
153  G4double densityCorr;
154
155  // LPM effect
156  G4double lpmEnergy;
157  G4PhysicsVector  *fXiLPM, *fPhiLPM, *fGLPM;
158  G4double xiLPM, phiLPM, gLPM;
159
160  // critical gamma energies
161  G4double klpm, kp;
162
163  G4bool   isElectron;
164
165private:
166  // consts
167  G4double highKinEnergy;
168  G4double lowKinEnergy;
169  G4double fMigdalConstant;
170  G4double fLPMconstant;
171  G4double bremFactor;
172  G4double energyThresholdLPM;
173  G4double facFel, facFinel;
174  G4double preS1,logTwo;
175
176  G4bool   use_completescreening;
177
178  G4bool   isInitialised;
179};
180
181//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
182
183inline void G4eBremsstrahlungRelModel::SetCurrentElement(const G4double Z)
184{
185  if(Z != currentZ) {
186    currentZ = Z;
187
188    G4int iz = G4int(Z);
189    z13 = nist->GetZ13(iz);
190    z23 = z13*z13;
191    lnZ = nist->GetLOGZ(iz);
192
193    if (iz <= 4) {
194      Fel = Fel_light[iz]; 
195      Finel = Finel_light[iz] ; 
196    }
197    else {
198      Fel = facFel - lnZ/3. ;
199      Finel = facFinel - 2.*lnZ/3. ;
200    }
201
202    fCoulomb=GetCurrentElement()->GetfCoulomb();
203    fMax   =  Fel-fCoulomb + Finel/currentZ  +  (1.+1./currentZ)/12.;
204  }
205}
206
207//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
208
209inline G4double
210G4eBremsstrahlungRelModel::MaxSecondaryEnergy(const G4ParticleDefinition*,
211                                              G4double kineticEnergy)
212{
213  return kineticEnergy;
214}
215
216//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
217
218
219inline G4double G4eBremsstrahlungRelModel::Phi1(G4double gg, G4double)
220{
221  //       Thomas-Fermi FF from Tsai, eq.(3.38) for Z>=5
222  return 20.863 - 2.*std::log(1. + sqr(0.55846*gg) )
223    - 4.*( 1. - 0.6*std::exp(-0.9*gg) - 0.4*std::exp(-1.5*gg) );
224}
225
226inline G4double G4eBremsstrahlungRelModel::Phi1M2(G4double gg, G4double)
227{
228  //       Thomas-Fermi FF from Tsai, eq. (3.39) for Z>=5
229  // return Phi1(gg,Z) -
230  return 2./(3.*(1. + 6.5*gg +6.*gg*gg) );
231}
232
233inline G4double G4eBremsstrahlungRelModel::Psi1(G4double eps, G4double)
234{
235  //       Thomas-Fermi FF from Tsai, eq.(3.40) for Z>=5
236  return 28.340 - 2.*std::log(1. + sqr(3.621*eps) )
237    - 4.*( 1. - 0.7*std::exp(-8*eps) - 0.3*std::exp(-29.*eps) );
238}
239
240inline G4double G4eBremsstrahlungRelModel::Psi1M2(G4double eps, G4double)
241{
242  //       Thomas-Fermi FF from Tsai, eq. (3.41) for Z>=5
243  return  2./(3.*(1. + 40.*eps +400.*eps*eps) );
244}
245
246//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
247
248inline 
249void G4eBremsstrahlungRelModel::SetLPMconstant(G4double val) 
250{
251  fLPMconstant = val;
252}
253
254//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
255
256inline 
257G4double G4eBremsstrahlungRelModel::LPMconstant() const 
258{
259  return fLPMconstant;
260}
261
262//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
263
264
265#endif
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