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25 //
26 // G4ScreeningMottCrossSection.hh
27 //-------------------------------------------------------------------
28 //
29 // GEANT4 Class header file
30 //
31 // File name: G4ScreeningMottCrossSection
32 //
33 // Author: Cristina Consolandi
34 //
35 // Creation date: 20.10.2011
36 //
37 // Modifications:
38 //
39 // Class Description:
40 // Computation of electron Coulomb Scattering Cross Section.
41 // Suitable for high energy electrons and light target materials.
42 //
43 // Reference:
44 // M.J. Boschini et al.
45 // "Non Ionizing Energy Loss induced by Electrons in the Space Environment"
46 // Proc. of the 13th Int. Conf. on Particle Physics and Advanced Technology
47 // (13th ICPPAT, Como 3-7/10/2011), World Scientific (Singapore).
48 // Available at: http://arxiv.org/abs/1111.4042v4
49 //
50 // 1) Mott Differential Cross Section Approximation:
51 // For Target material up to Z=92 (U):
52 // As described in http://arxiv.org/abs/1111.4042v4
53 // par. 2.1 , eq. (16)-(17)
54 // Else (Z>92):
55 // W. A. McKinley and H. Fashbach, Phys. Rev. 74, (1948) 1759.
56 // 2) Screening coefficient:
57 // vomn G. Moliere, Z. Naturforsh A2 (1947), 133-145; A3 (1948), 78.
58 // 3) Nuclear Form Factor:
59 // A.V. Butkevich et al. Nucl. Instr. Meth. A488 (2002), 282-294.
60 //
61 // -----------------------------------------------------------------------------
62
63 //
64 #ifndef G4ScreeningMottCrossSection_h
65 #define G4ScreeningMottCrossSection_h 1
66
67 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
68
69 #include "globals.hh"
70 #include "G4ParticleDefinition.hh"
71 #include <vector>
72
73 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
74
75 static const G4int DIMMOTT = 750;
76
77 class G4NistManager;
78 class G4Pow;
79
80 class G4ScreeningMottCrossSection
81 {
82
83 public:
84
85 explicit G4ScreeningMottCrossSection();
86
87 ~G4ScreeningMottCrossSection();
88
89 void Initialise(const G4ParticleDefinition*, G4double cosThetaLim);
90
91 void SetupKinematic(G4double kinEnergy, G4int Z);
92
93 G4double NuclearCrossSection(G4int form, G4int fast);
94 G4double GetScatteringAngle(G4int form, G4int fast);
95
96 G4double RatioMottRutherford(G4double tet);
97 G4double RatioMottRutherfordCosT(G4double sin2t2);
98
99 G4double McFcorrection(G4double sin2t2);
100 inline void SetupParticle(const G4ParticleDefinition*);
101
102 G4ScreeningMottCrossSection & operator=
103 (const G4ScreeningMottCrossSection &right) = delete;
104 G4ScreeningMottCrossSection(const G4ScreeningMottCrossSection&) = delete;
105
106 private:
107
108 G4double ComputeAngle(G4int idx, G4double& rand);
109
110 G4double FormFactor2ExpHof(G4double sin2t2);
111 G4double FormFactor2Gauss(G4double sin2t2);
112 G4double FormFactor2UniformHelm(G4double sin2t2);
113 G4double DifferentialXSection(G4int idx, G4int form);
114
115 G4double GetTransitionRandom();
116
117 G4NistManager* fNistManager;
118 G4Pow* fG4pow;
119
120 const G4ParticleDefinition* particle;
121
122 G4double fTotalCross;
123 //cost - min - max
124 G4double cosThetaMin;// def 1.0
125 G4double cosThetaMax;// def -1.0
126
127 G4double cosTetMinNuc;
128 G4double cosTetMaxNuc;
129
130 //energy cut
131 G4double ecut;
132 G4double etag;
133
134 G4double spin;
135 G4double mass;
136
137 //lab of incedent particle
138 G4double tkinLab;
139 G4double momLab2;
140 G4double invbetaLab2;
141
142 //relative system with nucleus
143 G4double mu_rel;
144 G4double tkin;
145 G4double mom2;
146 G4double invbeta2;
147 G4double beta;
148 G4double gamma;
149
150 //constants
151 G4double alpha;
152 G4double htc2;
153 G4double e2;
154
155 // target nucleus
156 G4double targetMass;
157 G4double As;
158 G4int targetZ;
159 G4int targetA;
160
161 // working array
162 std::vector<G4double> cross;
163 };
164
165
166 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
167
168 inline
169 void G4ScreeningMottCrossSection::SetupParticle(const G4ParticleDefinition* p)
170 {
171 particle = p;
172 mass = particle->GetPDGMass();
173 spin = particle->GetPDGSpin();
174 if(0.0 != spin) { spin = 0.5; }
175 tkin = 0.0;
176 }
177
178 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
179
180 #endif
181