Geant4  10.01.p03
G4NuclearFermiDensity.hh
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27 
28 #ifndef G4NuclearFermiDensity_h
29 #define G4NuclearFermiDensity_h 1
30 
31 #include "globals.hh"
32 #include "G4ThreeVector.hh"
33 #include "G4VNuclearDensity.hh"
34 
35 #include <CLHEP/Units/PhysicalConstants.h> // pi, fermi,..
36 #include <cmath> // pow
37 
39 {
40  public:
43 
44  G4double GetRelativeDensity(const G4ThreeVector & aPosition) const
45  {
46  return 1./(1.+std::exp((aPosition.mag()-theR)/a));
47  }
48 
49  G4double GetRadius(const G4double maxRelativeDenisty) const
50  {
51  return (maxRelativeDenisty>0 && maxRelativeDenisty <= 1 ) ?
52  (theR + a*std::log((1-maxRelativeDenisty+std::exp(-1*theR/a))/maxRelativeDenisty)) : DBL_MAX;
53  }
54 
55  G4double GetDeriv(const G4ThreeVector & aPosition) const
56  {
57  G4double currentR=aPosition.mag();
58  if (currentR > 40*theR ) {return 0;}
59  else return -std::exp((currentR-theR)/a) * sqr(GetDensity(aPosition)) / (a*Getrho0());
60  }
61 
62  private:
64  G4double theR; // Nuclear Radius
65  const G4double a; // Determines the nuclear surface thickness
66 };
67 
68 #endif
69 
CLHEP::Hep3Vector G4ThreeVector
G4double Getrho0() const
int G4int
Definition: G4Types.hh:78
G4double GetDeriv(const G4ThreeVector &aPosition) const
G4double GetRelativeDensity(const G4ThreeVector &aPosition) const
G4NuclearFermiDensity(G4int anA, G4int aZ)
G4double GetDensity(const G4ThreeVector &aPosition) const
G4double GetRadius(const G4double maxRelativeDenisty) const
T sqr(const T &x)
Definition: templates.hh:145
double G4double
Definition: G4Types.hh:76
#define DBL_MAX
Definition: templates.hh:83