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25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4hBremsstrahlungModel
33 //
34 // Author: Vladimir Ivanchenko on base of G4MuBremsstrahlungModel
35 //
36 // Creation date: 28.02.2008
37 //
38 // Modifications:
39 //
40
41 //
42 // Class Description:
43 //
44 //
45 // -------------------------------------------------------------------
46 //
47 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
48 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
49
50 #include "G4hBremsstrahlungModel.hh"
51 #include "G4PhysicalConstants.hh"
52 #include "G4SystemOfUnits.hh"
53 #include "G4Log.hh"
54 #include "G4NistManager.hh"
55
56 using namespace std;
57
58 G4hBremsstrahlungModel::G4hBremsstrahlungModel(const G4ParticleDefinition* p,
59 const G4String& nam)
60 : G4MuBremsstrahlungModel(p, nam)
61 {}
62
63 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
64
65 G4hBremsstrahlungModel::~G4hBremsstrahlungModel()
66 {}
67
68 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69
70 G4double G4hBremsstrahlungModel::ComputeDMicroscopicCrossSection(
71 G4double tkin,
72 G4double Z,
73 G4double gammaEnergy)
74 // differential cross section
75 {
76 G4double dxsection = 0.;
77
78 if(gammaEnergy > tkin) return dxsection;
79 // G4cout << "G4hBremsstrahlungModel m= " << mass
80 // << " " << particle->GetParticleName() << G4endl;
81 G4double E = tkin + mass ;
82 G4double v = gammaEnergy/E ;
83 G4double delta = 0.5*mass*mass*v/(E-gammaEnergy);
84 G4double rab0=delta*sqrte ;
85
86 G4int iz = std::max(G4lrint(Z), 1);
87
88 G4double z13 = 1.0/nist->GetZ13(iz);
89 G4double dn = mass*nist->GetA27(iz)/(70.*MeV);
90
91 G4double b = (1 == iz) ? bh : btf;
92
93 // nucleus contribution logarithm
94 G4double rab1=b*z13;
95 G4double fn=G4Log(rab1/(dn*(electron_mass_c2+rab0*rab1))*
96 (mass+delta*(dn*sqrte-2.))) ;
97 fn = std::max(fn, 0.0);
98
99 G4double x = 1.0 - v;
100 if(particle->GetPDGSpin() != 0) { x += 0.75*v*v; }
101
102 dxsection = coeff*x*Z*Z*fn/gammaEnergy;
103
104 return dxsection;
105 }
106
107 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
108