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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
47 G4PreCompoundIon::
48 G4PreCompoundIon(const G4ParticleDefinition* part,
49 G4VCoulombBarrier* aCoulombBarrier)
50 : G4PreCompoundFragment(part,aCoulombBarrier)
51 {
52 G4double r0 = theParameters->GetR0();
53 fact = 0.75*CLHEP::millibarn/(CLHEP::pi*r0*r0*r0);
54 }
55
56 G4double G4PreCompoundIon::
57 ProbabilityDistributionFunction(G4double eKin,
58 const G4Fragment& aFragment)
59 {
60 G4double efinal = eKin + theBindingEnergy;
61 if(efinal <= 0.0 ) { return 0.0; }
62
63 G4double U = aFragment.GetExcitationEnergy();
64 G4int P = aFragment.GetNumberOfParticles();
65 G4int H = aFragment.GetNumberOfHoles();
66 G4int A = GetA();
67 G4int N = P + H;
68
69 static const G4double sixoverpi2 = 6.0/CLHEP::pi2;
70 G4double g0 = sixoverpi2*fNucData->GetLevelDensity(theFragZ, theFragA, U);
71 G4double g1 = sixoverpi2*fNucData->GetLevelDensity(theResZ, theResA, 0.0);
72
73 G4double gj = g1;
74
75 G4double A0 = (P*P+H*H+P-3*H)/(4.0*g0);
76 G4double A1 = std::max(0.0,(A0*g0 + A*(A-2*P-1)*0.25)/g1);
77
78 G4double E0 = U - A0;
79 if (E0 <= 0.0) { return 0.0; }
80
81 G4double E1 = std::max(0.0,theMaxKinEnergy - eKin - A1);
82
83 G4double Aj = A*(A+1)/(4.0*gj);
84 G4double Ej = std::max(0.0,efinal - Aj);
85
86 G4double rj = GetRj(P, aFragment.GetNumberOfCharged());
87 G4double xs = CrossSection(eKin);
88
89 G4double pA = fact*eKin*xs*rj
90 * CoalescenceFactor(theFragA) * FactorialFactor(N,P)
91 * std::sqrt(2.0/(theReducedMass*efinal))
92 * g4calc->powN(g1*E1/(g0*E0), N-A-1)
93 * g4calc->powN(gj*Ej/(g0*E0), A-1)*gj*g1/(g0*g0*E0*theResA);
94
95 return pA;
96 }
97