Geant4  10.01.p02
G4FissionProbability.cc
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27 // $Id: G4FissionProbability.cc 84396 2014-10-15 07:18:24Z gcosmo $
28 //
29 // Hadronic Process: Nuclear De-excitations
30 // by V. Lara (Oct 1998)
31 //
32 //
33 // J.M.Quesada (14 february 2009) bug fixed in fission width: missing parenthesis in the denominator
34 
35 
36 #include "G4FissionProbability.hh"
37 #include "G4PhysicalConstants.hh"
38 #include "G4PairingCorrection.hh"
41 
43  theEvapLDP(new G4EvaporationLevelDensityParameter),
44  theFissLDP(new G4FissionLevelDensityParameter),
45  ownEvapLDP(true),
46  ownFissLDP(true)
47 {}
48 
50 {
51  if (ownEvapLDP) delete theEvapLDP;
52  if (ownFissLDP) delete theFissLDP;
53 }
54 
55 
56 G4double
58  G4double MaximalKineticEnergy)
59  // Compute integrated probability of fission channel
60 {
61  if (MaximalKineticEnergy <= 0.0) return 0.0;
62  G4int A = fragment.GetA_asInt();
63  G4int Z = fragment.GetZ_asInt();
64  G4double U = fragment.GetExcitationEnergy();
65 
66  G4double Ucompound = U -
68 
69  G4double Ufission = U -
71 
72  G4double SystemEntropy =
73  2.0*std::sqrt(theEvapLDP->LevelDensityParameter(A,Z,Ucompound)*Ucompound);
74 
75  G4double afission = theFissLDP->LevelDensityParameter(A,Z,Ufission);
76 
77  G4double Cf = 2.0*std::sqrt(afission*MaximalKineticEnergy);
78 
79  // G4double Q1 = 1.0 + (Cf - 1.0)*std::exp(Cf);
80  // G4double Q2 = 4.0*pi*afission*std::exp(SystemEntropy);
81 
82  // G4double probability = Q1/Q2;
83 
84  G4double Exp1 = 0.0;
85  if (SystemEntropy <= 160.0) { Exp1 = std::exp(-SystemEntropy); }
86  // @@@@@@@@@@@@@@@@@ hpw changed max to min - cannot notify vicente now
87  G4double Exp2 = std::exp( std::min(700.0,Cf-SystemEntropy) );
88 
89  // JMQ 14/02/09 BUG fixed in fission probability (missing parenthesis
90  // at denominator)
91  //AH fix from Vincente: G4double probability =
92  // (Exp1 + (1.0-Cf)*Exp2) / 4.0*pi*afission;
93  // G4double probability = (Exp1 + (Cf-1.0)*Exp2) / 4.0*pi*afission;
94  G4double probability = (Exp1 + (Cf-1.0)*Exp2) / (4.0*pi*afission);
95 
96  return probability;
97 }
98 
G4double EmissionProbability(const G4Fragment &fragment, G4double MaximalKineticEnergy)
const G4double pi
int G4int
Definition: G4Types.hh:78
G4int GetA_asInt() const
Definition: G4Fragment.hh:243
G4double GetPairingCorrection(G4int A, G4int Z) const
static const G4double A[nN]
static G4PairingCorrection * GetInstance()
G4double GetFissionPairingCorrection(G4int A, G4int Z) const
G4VLevelDensityParameter * theEvapLDP
virtual G4double LevelDensityParameter(G4int A, G4int Z, G4double U) const =0
T min(const T t1, const T t2)
brief Return the smallest of the two arguments
G4int GetZ_asInt() const
Definition: G4Fragment.hh:248
double G4double
Definition: G4Types.hh:76
G4double GetExcitationEnergy() const
Definition: G4Fragment.hh:260
G4VLevelDensityParameter * theFissLDP