Geant4  10.01
G4BetaFermiFunction.cc
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27 #include "globals.hh"
28 #include "G4BetaFermiFunction.hh"
29 
30 const G4double G4BetaFermiFunction::PI=3.14159;
31 
33 //
34 // calculate the Fermi Function foe energy E0
35 //
37 {
38  G4double A1, A2;
39  G4double P, U, S, Y;
40  G4double F2;
41  G4double E = E0+1.;
42  P=std::sqrt(E*E-1.0) ;
43  U=Z/137.0;
44  S=std::sqrt(1.0-U*U) - 1.;
45  Y = 2*PI*U*E/P;
46  A1 = U*U*E*E + P*P/4.;
47  A2 = std::fabs(Y/(1-std::exp(-Y)));
48  F2 = std::pow(A1,S) * A2;
49  return F2;
50 }
51 
53 //
54 // calculate the Fermi normalization factor
55 // here E0 is the end point energy of the beta decay
56 //
58 {
59 
60  G4double A1, A2;
61  G4double P, U, S, Y;
62  G4double F2,E;
63  G4double EE = E0/100.;
64  U=Z/137.0;
65  S=std::sqrt(1.0-U*U) - 1.;
66  G4double F1 = 1E-10;
67  for (G4int i = 1; i<=100 ; i++) {
68  E = G4double(i)*EE + 1.;
69  P=std::sqrt(E*E-1.0) ;
70  Y = 2*PI*U*E/P;
71  A1 = U*U*E*E + P*P/4.;
72  A2 = std::fabs(Y/(1-std::exp(-Y)));
73  F2 = std::pow(A1,S) * A2;
74  if (F2 > F1) F1 = F2;
75  }
76  return F1;
77 }
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static const G4double PI
int G4int
Definition: G4Types.hh:78
G4double GetFF(const G4double E)
G4double GetFFN(const G4double E0)
double G4double
Definition: G4Types.hh:76