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25 //
26 //
27 //
28 // P. Arce, June-2014 Conversion neutron_hp to particle_hp
29 //
30 #include "G4ParticleHPNBodyPhaseSpace.hh"
31
32 #include "G4Alpha.hh"
33 #include "G4Deuteron.hh"
34 #include "G4Electron.hh"
35 #include "G4Gamma.hh"
36 #include "G4He3.hh"
37 #include "G4Neutron.hh"
38 #include "G4PhysicalConstants.hh"
39 #include "G4Positron.hh"
40 #include "G4Proton.hh"
41 #include "G4ThreeVector.hh"
42 #include "G4Triton.hh"
43 #include "Randomize.hh"
44
45 G4ReactionProduct* G4ParticleHPNBodyPhaseSpace::Sample(G4double anEnergy, G4double massCode,
46 G4double)
47 {
48 auto result = new G4ReactionProduct;
49 auto Z = static_cast<G4int>(massCode / 1000);
50 auto A = static_cast<G4int>(massCode - 1000 * Z);
51
52 if (massCode == 0) {
53 result->SetDefinition(G4Gamma::Gamma());
54 }
55 else if (A == 0) {
56 result->SetDefinition(G4Electron::Electron());
57 if (Z == 1) result->SetDefinition(G4Positron::Positron());
58 }
59 else if (A == 1) {
60 result->SetDefinition(G4Neutron::Neutron());
61 if (Z == 1) result->SetDefinition(G4Proton::Proton());
62 }
63 else if (A == 2) {
64 result->SetDefinition(G4Deuteron::Deuteron());
65 }
66 else if (A == 3) {
67 result->SetDefinition(G4Triton::Triton());
68 if (Z == 2) result->SetDefinition(G4He3::He3());
69 }
70 else if (A == 4) {
71 result->SetDefinition(G4Alpha::Alpha());
72 if (Z != 2) throw G4HadronicException(__FILE__, __LINE__, "Unknown ion case 1");
73 }
74 else {
75 throw G4HadronicException(__FILE__, __LINE__,
76 "G4ParticleHPNBodyPhaseSpace: Unknown ion case 2");
77 }
78
79 // Get the energy from phase-space distribution
80 // in CMS
81 // P = Cn*std::sqrt(E')*(Emax-E')**(3*n/2-4)
82 G4double maxE = GetEmax(anEnergy, result->GetMass());
83 if (maxE <= 0) {
84 maxE = 1. * CLHEP::eV;
85 }
86 G4double energy = 0.;
87 G4double max(0);
88 if (theTotalCount <= 3) {
89 max = maxE / 2.;
90 }
91 else if (theTotalCount == 4) {
92 max = maxE / 5.;
93 }
94 else if (theTotalCount == 5) {
95 max = maxE / 8.;
96 }
97 else {
98 throw G4HadronicException(
99 __FILE__, __LINE__,
100 "NeutronHP Phase-space distribution cannot cope with this number of particles");
101 }
102 G4double testit;
103 G4double rand0 = Prob(max, maxE, theTotalCount);
104 G4double rand;
105
106 G4int icounter = 0;
107 G4int icounter_max = 1024;
108 do {
109 icounter++;
110 if (icounter > icounter_max) {
111 G4cout << "Loop-counter exceeded the threshold value at " << __LINE__ << "th line of "
112 << __FILE__ << "." << G4endl;
113 break;
114 }
115 rand = rand0 * G4UniformRand();
116 energy = maxE * G4UniformRand();
117 testit = Prob(energy, maxE, theTotalCount);
118 } while (rand > testit); // Loop checking, 11.05.2015, T. Koi
119 result->SetKineticEnergy(energy);
120
121 // now do random direction
122 G4double cosTh = 2. * G4UniformRand() - 1.;
123 G4double phi = twopi * G4UniformRand();
124 G4double theta = std::acos(cosTh);
125 G4double sinth = std::sin(theta);
126 G4double mtot = result->GetTotalMomentum();
127 G4ThreeVector tempVector(mtot * sinth * std::cos(phi), mtot * sinth * std::sin(phi),
128 mtot * std::cos(theta));
129 result->SetMomentum(tempVector);
130 G4ReactionProduct aCMS = *GetTarget() + *GetProjectileRP();
131 result->Lorentz(*result, -1. * aCMS);
132 return result;
133 }
134