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G4PreCompoundIon.cc
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25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4PreCompoundIon
33 //
34 // Author: V.Lara
35 //
36 // Modified:
37 // 10.02.2009 J. M. Quesada fixed bug in level density of light fragments
38 // 20.08.2010 V.Ivanchenko added G4Pow and G4PreCompoundParameters pointers
39 // use int Z and A and cleanup
40 //
41 
42 #include "G4PreCompoundIon.hh"
43 #include "G4PhysicalConstants.hh"
44 #include "G4NuclearLevelData.hh"
45 #include "G4DeexPrecoParameters.hh"
46 
49  G4VCoulombBarrier* aCoulombBarrier)
50  : G4PreCompoundFragment(part,aCoulombBarrier)
51 {
53  fact = 0.75*CLHEP::millibarn/(CLHEP::pi*r0*r0*r0);
54 }
55 
57 {}
58 
61  const G4Fragment& aFragment)
62 {
63  G4double efinal = eKin + theBindingEnergy;
64  if(efinal <= 0.0 ) { return 0.0; }
65 
66  G4double U = aFragment.GetExcitationEnergy();
67  G4int P = aFragment.GetNumberOfParticles();
68  G4int H = aFragment.GetNumberOfHoles();
69  G4int A = GetA();
70  G4int N = P + H;
71 
72  static const G4double sixoverpi2 = 6.0/CLHEP::pi2;
73  G4double g0 = sixoverpi2*fNucData->GetLevelDensity(theFragZ, theFragA, U);
74  G4double g1 = sixoverpi2*fNucData->GetLevelDensity(theResZ, theResA, 0.0);
75 
76  G4double gj = g1;
77 
78  G4double A0 = G4double(P*P+H*H+P-3*H)/(4.0*g0);
79  G4double A1 = std::max(0.0,(A0*g0 + A*(A-2*P-1)*0.25)/g1);
80 
81  G4double E0 = U - A0;
82  if (E0 <= 0.0) { return 0.0; }
83 
84  G4double E1 = std::max(0.0,theMaxKinEnergy - eKin - A1);
85 
86  G4double Aj = A*(A+1)/(4.0*gj);
87  G4double Ej = std::max(0.0,efinal - Aj);
88 
89  G4double rj = GetRj(P, aFragment.GetNumberOfCharged());
90  G4double xs = CrossSection(eKin);
91 
92  G4double pA = fact*eKin*xs*rj
94  * std::sqrt(2.0/(theReducedMass*efinal))
95  * g4calc->powN(g1*E1/(g0*E0), N-A-1)
96  * g4calc->powN(gj*Ej/(g0*E0), A-1)*gj*g1/(g0*g0*E0*theResA);
97 
98  return pA;
99 }
100 
102 {
103  return -theCoulombBarrier;
104 }