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G4hBremsstrahlungModel.cc
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26 // $Id: G4hBremsstrahlungModel.cc 74020 2013-09-19 13:38:38Z gcosmo $
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4hBremsstrahlungModel
34 //
35 // Author: Vladimir Ivanchenko on base of G4MuBremsstrahlungModel
36 //
37 // Creation date: 28.02.2008
38 //
39 // Modifications:
40 //
41 
42 //
43 // Class Description:
44 //
45 //
46 // -------------------------------------------------------------------
47 //
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50 
52 #include "G4PhysicalConstants.hh"
53 #include "G4SystemOfUnits.hh"
54 #include "G4Log.hh"
55 
56 using namespace std;
57 
59  const G4String& nam)
60  : G4MuBremsstrahlungModel(p, nam)
61 {}
62 
63 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
64 
66 {}
67 
68 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69 
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 = G4int(Z);
87  if(iz < 1) { iz = 1; }
88 
89  G4double z13 = 1.0/nist->GetZ13(iz);
90  G4double dn = mass*nist->GetA27(iz)/(70.*MeV);
91 
92  G4double b = btf;
93  if(1 == iz) b = bh;
94 
95  // nucleus contribution logarithm
96  G4double rab1=b*z13;
97  G4double fn=G4Log(rab1/(dn*(electron_mass_c2+rab0*rab1))*
98  (mass+delta*(dn*sqrte-2.))) ;
99  if(fn <0.) fn = 0. ;
100 
101  G4double x = 1.0 - v;
102  if(particle->GetPDGSpin() != 0) { x += 0.75*v*v; }
103 
104  dxsection = coeff*x*Z*Z*fn/gammaEnergy;
105 
106  return dxsection;
107 }
108 
109 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
const char * p
Definition: xmltok.h:285
G4double GetA27(G4int Z) const
virtual G4double ComputeDMicroscopicCrossSection(G4double tkin, G4double Z, G4double gammaEnergy) override
int G4int
Definition: G4Types.hh:78
static constexpr double electron_mass_c2
G4double GetZ13(G4double Z) const
const G4ParticleDefinition * particle
G4hBremsstrahlungModel(const G4ParticleDefinition *p=nullptr, const G4String &nam="hBrem")
G4double G4Log(G4double x)
Definition: G4Log.hh:230
G4double GetPDGSpin() const
static constexpr double MeV
Definition: G4SIunits.hh:214
double G4double
Definition: G4Types.hh:76