Geant4_10
G4WentzelOKandVIxSection.hh
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26 // $Id: G4WentzelOKandVIxSection.hh 69548 2013-05-08 10:03:12Z gcosmo $
27 //
28 // -------------------------------------------------------------------
29 //
30 //
31 // GEANT4 Class header file
32 //
33 //
34 // File name: G4WentzelOKandVIxSection
35 //
36 // Authors: V.Ivanchenko and O.Kadri
37 //
38 // Creation date: 21.05.2010
39 //
40 // Modifications:
41 //
42 //
43 // Class Description:
44 //
45 // Implementation of the computation of total and transport cross sections,
46 // sample scattering angle for the single scattering case.
47 // to be used by single and multiple scattering models. References:
48 // 1) G.Wentzel, Z. Phys. 40 (1927) 590.
49 // 2) J.M. Fernandez-Varea et al., NIM B73 (1993) 447.
50 //
51 // -------------------------------------------------------------------
52 //
53 
54 #ifndef G4WentzelOKandVIxSection_h
55 #define G4WentzelOKandVIxSection_h 1
56 
57 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
58 
59 #include "globals.hh"
60 #include "G4Material.hh"
61 #include "G4Element.hh"
62 #include "G4ElementVector.hh"
63 #include "G4NistManager.hh"
64 #include "G4ThreeVector.hh"
65 #include "G4Pow.hh"
66 
68 
69 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
70 
72 {
73 
74 public:
75 
77 
78  virtual ~G4WentzelOKandVIxSection();
79 
80  void Initialise(const G4ParticleDefinition*, G4double CosThetaLim);
81 
83 
84  // return cos(ThetaMax) for msc and cos(thetaMin) for single scattering
85  // cut = DBL_MAX means no scattering off electrons
87 
89 
91  G4double CosThetaMax,
92  G4double elecRatio = 0.0);
93 
94  inline G4double ComputeNuclearCrossSection(G4double CosThetaMin,
95  G4double CosThetaMax);
96 
98  G4double CosThetaMax);
99 
100  inline G4double SetupKinematic(G4double kinEnergy, const G4Material* mat);
101 
102  inline void SetTargetMass(G4double value);
103 
104  inline G4double GetMomentumSquare() const;
105 
106  inline G4double GetCosThetaNuc() const;
107 
108  inline G4double GetCosThetaElec() const;
109 
110 private:
111 
112  void ComputeMaxElectronScattering(G4double cut);
113 
114  // hide assignment operator
117 
118  const G4ParticleDefinition* theProton;
119  const G4ParticleDefinition* theElectron;
120  const G4ParticleDefinition* thePositron;
121  const G4Material* currentMaterial;
122 
123  G4NistManager* fNistManager;
124  G4Pow* fG4pow;
125 
126  G4double numlimit;
127 
128  G4double elecXSRatio;
129 
130  // integer parameters
131  G4int nwarnings;
132  G4int nwarnlimit;
133 
134  // single scattering parameters
135  G4double coeff;
136  G4double cosTetMaxElec;
137  G4double cosTetMaxNuc;
138  G4double cosThetaMax;
139  G4double alpha2;
140 
141  // projectile
142  const G4ParticleDefinition* particle;
143 
144  G4double chargeSquare;
145  G4double charge3;
146  G4double spin;
147  G4double mass;
148  G4double tkin;
149  G4double mom2;
150  G4double momCM2;
151  G4double invbeta2;
152  G4double kinFactor;
153  G4double etag;
154  G4double ecut;
155  G4double lowEnergyLimit;
156 
157  // target
158  G4int targetZ;
159  G4double targetMass;
160  G4double screenZ;
161  G4double formfactA;
162  G4double factorA2;
163  G4double factB;
164  G4double factB1;
165  G4double factD;
166  G4double gam0pcmp;
167  G4double pcmp2;
168 
169  static G4double ScreenRSquareElec[100];
170  static G4double ScreenRSquare[100];
171  static G4double FormFactor[100];
172 };
173 
174 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
175 
176 inline G4double
178 {
179  if(ekin != tkin || mat != currentMaterial) {
180  currentMaterial = mat;
181  tkin = ekin;
182  mom2 = tkin*(tkin + 2.0*mass);
183  invbeta2 = 1.0 + mass*mass/mom2;
184  factB = spin/invbeta2;
185  cosTetMaxNuc =
186  std::max(cosThetaMax,1.-factorA2*mat->GetIonisation()->GetInvA23()/mom2);
187  }
188  return cosTetMaxNuc;
189 }
190 
191 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
192 
194 {
195  targetMass = value;
196  factD = std::sqrt(mom2)/value;
197 }
198 
199 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
200 
202 {
203  return mom2;
204 }
205 
206 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
207 
209 {
210  return cosTetMaxNuc;
211 }
212 
213 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
214 
216 {
217  return cosTetMaxElec;
218 }
219 
220 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
221 
222 inline G4double
224  G4double cosTMax)
225 {
226  G4double xsec = 0.0;
227  if(cosTMax < cosTMin) {
228  xsec = targetZ*kinFactor*(cosTMin - cosTMax)/
229  ((1.0 - cosTMin + screenZ)*(1.0 - cosTMax + screenZ));
230  }
231  return xsec;
232 }
233 
234 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
235 
236 inline G4double
238  G4double cosTMax)
239 {
240  G4double xsec = 0.0;
241  G4double cost1 = std::max(cosTMin,cosTetMaxElec);
242  G4double cost2 = std::max(cosTMax,cosTetMaxElec);
243  if(cost1 > cost2) {
244  xsec = kinFactor*(cost1 - cost2)/((1.0 - cost1 + screenZ)*(1.0 - cost2 + screenZ));
245  }
246  return xsec;
247 }
248 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
249 
250 #endif
251 
void SetupParticle(const G4ParticleDefinition *)
G4IonisParamMat * GetIonisation() const
Definition: G4Material.hh:224
Definition: G4Pow.hh:56
G4ThreeVector SampleSingleScattering(G4double CosThetaMin, G4double CosThetaMax, G4double elecRatio=0.0)
int G4int
Definition: G4Types.hh:78
G4double SetupTarget(G4int Z, G4double cut=DBL_MAX)
Float_t mat
Definition: plot.C:40
G4double ComputeTransportCrossSectionPerAtom(G4double CosThetaMax)
Float_t Z
Definition: plot.C:39
G4double GetInvA23() const
G4double SetupKinematic(G4double kinEnergy, const G4Material *mat)
G4double ComputeElectronCrossSection(G4double CosThetaMin, G4double CosThetaMax)
T max(const T t1, const T t2)
brief Return the largest of the two arguments
G4double ComputeNuclearCrossSection(G4double CosThetaMin, G4double CosThetaMax)
const XML_Char int const XML_Char * value
Definition: expat.h:331
double G4double
Definition: G4Types.hh:76
#define DBL_MAX
Definition: templates.hh:83
void Initialise(const G4ParticleDefinition *, G4double CosThetaLim)