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27 // 27 // //
28 // File: G4BetaPlusDecay.cc 28 // File: G4BetaPlusDecay.cc //
29 // Author: D.H. Wright (SLAC) 29 // Author: D.H. Wright (SLAC) //
30 // Date: 14 November 2014 30 // Date: 14 November 2014 //
31 // Modifications: 31 // Modifications: //
32 // 23.08.2023 V.Ivanchenko 32 // 23.08.2023 V.Ivanchenko //
33 // 33 // //
34 ////////////////////////////////////////////// 34 ////////////////////////////////////////////////////////////////////////////////
35 35
36 #include "G4BetaPlusDecay.hh" 36 #include "G4BetaPlusDecay.hh"
37 #include "G4BetaDecayCorrections.hh" 37 #include "G4BetaDecayCorrections.hh"
38 #include "G4IonTable.hh" 38 #include "G4IonTable.hh"
39 #include "G4ThreeVector.hh" 39 #include "G4ThreeVector.hh"
40 #include "G4LorentzVector.hh" 40 #include "G4LorentzVector.hh"
41 #include "G4DynamicParticle.hh" 41 #include "G4DynamicParticle.hh"
42 #include "G4DecayProducts.hh" 42 #include "G4DecayProducts.hh"
43 #include "G4PhysicalConstants.hh" 43 #include "G4PhysicalConstants.hh"
44 #include "G4SystemOfUnits.hh" 44 #include "G4SystemOfUnits.hh"
45 #include "G4Positron.hh" 45 #include "G4Positron.hh"
46 #include "G4NeutrinoE.hh" 46 #include "G4NeutrinoE.hh"
47 #include "G4RandomDirection.hh" 47 #include "G4RandomDirection.hh"
48 #include "G4BetaSpectrumSampler.hh" 48 #include "G4BetaSpectrumSampler.hh"
49 #include <iostream> 49 #include <iostream>
50 #include <iomanip> 50 #include <iomanip>
51 51
52 namespace { 52 namespace {
53 const G4double eMass = CLHEP::electron_mass_ 53 const G4double eMass = CLHEP::electron_mass_c2;
54 } 54 }
55 55
56 G4BetaPlusDecay::G4BetaPlusDecay(const G4Parti 56 G4BetaPlusDecay::G4BetaPlusDecay(const G4ParticleDefinition* theParentNucleus,
57 const G4doubl 57 const G4double& branch, const G4double& e0,
58 const G4doubl 58 const G4double& excitationE,
59 const G4Ions: 59 const G4Ions::G4FloatLevelBase& flb,
60 const G4BetaD 60 const G4BetaDecayType& betaType)
61 : G4NuclearDecay("beta+ decay", BetaPlus, exc 61 : G4NuclearDecay("beta+ decay", BetaPlus, excitationE, flb),
62 maxEnergy(e0/eMass - 2.0), << 62 maxEnergy((e0 - 2*eMass)/eMass),
63 estep(maxEnergy/(G4double)(npti - 1)) 63 estep(maxEnergy/(G4double)(npti - 1))
64 { 64 {
65 SetParent(theParentNucleus); // Store name 65 SetParent(theParentNucleus); // Store name of parent nucleus, delete G4MT_parent
66 SetBR(branch); 66 SetBR(branch);
67 SetNumberOfDaughters(3); 67 SetNumberOfDaughters(3);
68 68
69 fPrimaryIon = theParentNucleus; 69 fPrimaryIon = theParentNucleus;
70 fLepton = G4Positron::Positron(); 70 fLepton = G4Positron::Positron();
71 fNeutrino = G4NeutrinoE::NeutrinoE(); 71 fNeutrino = G4NeutrinoE::NeutrinoE();
72 72
73 G4IonTable* theIonTable = G4ParticleTable::G 73 G4IonTable* theIonTable = G4ParticleTable::GetParticleTable()->GetIonTable();
74 G4int daughterZ = theParentNucleus->GetAtomi 74 G4int daughterZ = theParentNucleus->GetAtomicNumber() - 1;
75 G4int daughterA = theParentNucleus->GetAtomi 75 G4int daughterA = theParentNucleus->GetAtomicMass();
76 fResIon = const_cast<const G4ParticleDefinit 76 fResIon = const_cast<const G4ParticleDefinition*>(theIonTable->GetIon(daughterZ, daughterA,
77 77 excitationE, flb));
78 78
79 parentMass = theParentNucleus->GetPDGMass(); 79 parentMass = theParentNucleus->GetPDGMass();
80 resMass = fResIon->GetPDGMass(); 80 resMass = fResIon->GetPDGMass();
81 81
82 SetUpBetaSpectrumSampler(daughterZ, daughter 82 SetUpBetaSpectrumSampler(daughterZ, daughterA, betaType);
83 83
84 SetDaughter(0, fResIon); 84 SetDaughter(0, fResIon);
85 SetDaughter(1, fLepton); 85 SetDaughter(1, fLepton);
86 SetDaughter(2, fNeutrino); 86 SetDaughter(2, fNeutrino);
87 87
88 // Fill G4MT_parent with theParentNucleus (s 88 // Fill G4MT_parent with theParentNucleus (stored by SetParent in ctor)
89 CheckAndFillParent(); 89 CheckAndFillParent();
90 90
91 // Fill G4MT_daughters with e+, nu and resid << 91 // Fill G4MT_daughters with e-, nu and residual nucleus (stored by SetDaughter)
92 CheckAndFillDaughters(); 92 CheckAndFillDaughters();
93 } 93 }
94 94
95 G4DecayProducts* G4BetaPlusDecay::DecayIt(G4do 95 G4DecayProducts* G4BetaPlusDecay::DecayIt(G4double)
96 { 96 {
97 // Set up final state 97 // Set up final state
98 // parentParticle is set at rest here becaus 98 // parentParticle is set at rest here because boost with correct momentum
99 // is done later 99 // is done later
100 G4DynamicParticle prim(fPrimaryIon, G4ThreeV 100 G4DynamicParticle prim(fPrimaryIon, G4ThreeVector(0,0,1), 0.0);
101 G4DecayProducts* products = new G4DecayProdu 101 G4DecayProducts* products = new G4DecayProducts(prim);
102 102
103 // Generate positron isotropic in angle, wit 103 // Generate positron isotropic in angle, with energy from stored spectrum
104 const G4double eKE = eMass*G4BetaSpectrumSam 104 const G4double eKE = eMass*G4BetaSpectrumSampler::shoot(npti, cdf, estep);
105 105
106 G4double eMomentum = std::sqrt(eKE*(eKE + 2. 106 G4double eMomentum = std::sqrt(eKE*(eKE + 2.*eMass));
107 G4ThreeVector dir = G4RandomDirection(); 107 G4ThreeVector dir = G4RandomDirection();
108 G4DynamicParticle* dp = new G4DynamicParticl 108 G4DynamicParticle* dp = new G4DynamicParticle(fLepton, dir, eKE);
109 products->PushProducts(dp); 109 products->PushProducts(dp);
110 /* 110 /*
111 G4cout << "G4BetaPlusDecay::DecayIt: " << fP 111 G4cout << "G4BetaPlusDecay::DecayIt: " << fPrimaryIon->GetParticleName()
112 << " -> " << fResIon->GetParticleName() << 112 << " -> " << fResIon->GetParticleName() << " + " << fLepton->GetParticleName()
113 << " + " << fNeutrino->GetParticleName() << 113 << " + " << fNeutrino->GetParticleName() << " Ee(MeV)=" << eKE
114 << G4endl; 114 << G4endl;
115 */ 115 */
116 // 4-momentum of residual ion and neutrino 116 // 4-momentum of residual ion and neutrino
117 G4LorentzVector lv(-eMomentum*dir.x(), -eMom 117 G4LorentzVector lv(-eMomentum*dir.x(), -eMomentum*dir.y(), -eMomentum*dir.z(),
118 parentMass - eKE - eMass) 118 parentMass - eKE - eMass);
119 119
120 const G4double elim = CLHEP::eV; << 120 G4double edel = std::max(lv.e() - resMass, 0.0);
121 // centrum of mass system << 121 if (edel > CLHEP::eV) {
122 G4double M = lv.mag(); << 122
123 G4double edel = M - resMass; << 123 // centrum of mass system
124 // Free energy should be above limit << 124 G4double M = lv.mag();
125 if (edel >= elim) { << 125
126 // neutrino 126 // neutrino
127 G4double eNu = 0.5*(M - resMass*resMass/M) 127 G4double eNu = 0.5*(M - resMass*resMass/M);
128 G4LorentzVector lvnu(eNu*G4RandomDirection 128 G4LorentzVector lvnu(eNu*G4RandomDirection(), eNu);
129 lvnu.boost(lv.boostVector()); 129 lvnu.boost(lv.boostVector());
130 dir = lvnu.vect().unit(); 130 dir = lvnu.vect().unit();
131 dp = new G4DynamicParticle(fNeutrino, dir, 131 dp = new G4DynamicParticle(fNeutrino, dir, lvnu.e());
132 products->PushProducts(dp); 132 products->PushProducts(dp);
133 133
134 // residual 134 // residual
135 lv -= lvnu; 135 lv -= lvnu;
136 dir = lv.vect().unit(); 136 dir = lv.vect().unit();
137 G4double ekin = std::max(lv.e() - resMass, 137 G4double ekin = std::max(lv.e() - resMass, 0.0);
138 dp = new G4DynamicParticle(fResIon, dir, e 138 dp = new G4DynamicParticle(fResIon, dir, ekin);
139 products->PushProducts(dp); 139 products->PushProducts(dp);
140 140
141 } else { 141 } else {
142 // neglecting relativistic kinematic and g 142 // neglecting relativistic kinematic and giving all energy to neutrino
143 dp = new G4DynamicParticle(fNeutrino, G4Ra << 143 dp = new G4DynamicParticle(fNeutrino, G4RandomDirection(), edel);
144 products->PushProducts(dp); 144 products->PushProducts(dp);
145 dp = new G4DynamicParticle(fResIon, G4Thre 145 dp = new G4DynamicParticle(fResIon, G4ThreeVector(0.0,0.0,1.0), 0.0);
146 products->PushProducts(dp); 146 products->PushProducts(dp);
147 } 147 }
148 148
149 return products; 149 return products;
150 } 150 }
151 151
152 152
153 void 153 void
154 G4BetaPlusDecay::SetUpBetaSpectrumSampler(cons 154 G4BetaPlusDecay::SetUpBetaSpectrumSampler(const G4int& daughterZ,
155 cons 155 const G4int& daughterA,
156 cons 156 const G4BetaDecayType& betaType)
157 { 157 {
158 cdf[0] = 0.0; <<
159 <<
160 // Check for cases in which Q < 2Me (e.g. z6 158 // Check for cases in which Q < 2Me (e.g. z67.a162)
161 if (maxEnergy > 0.) { 159 if (maxEnergy > 0.) {
162 G4BetaDecayCorrections corrections(-daught 160 G4BetaDecayCorrections corrections(-daughterZ, daughterA);
163 161
164 // Fill array to store cumulative spectrum 162 // Fill array to store cumulative spectrum
165 G4double ex; // Positron kinetic energy << 163 G4double ex;
166 G4double p; // Positron momentum in unit 164 G4double p; // Positron momentum in units of electron mass
167 G4double f; // Spectral shape function 165 G4double f; // Spectral shape function
168 G4double f0 = 0.0; <<
169 G4double sum = 0.0; 166 G4double sum = 0.0;
170 for (G4int i = 1; i < npti-1; ++i) { << 167 for (G4int i = 0; i < npti; ++i) {
171 ex = estep*i; << 168 ex = (0 == i) ? maxEnergy*1.e-6 : estep*i;
172 p = std::sqrt(ex*(ex + 2.)); 169 p = std::sqrt(ex*(ex + 2.));
173 f = p*(1. + ex)*(maxEnergy - ex)*(maxEne 170 f = p*(1. + ex)*(maxEnergy - ex)*(maxEnergy - ex);
174 171
175 // Apply Fermi factor to get allowed sha 172 // Apply Fermi factor to get allowed shape
176 f *= corrections.FermiFunction(1. + ex); 173 f *= corrections.FermiFunction(1. + ex);
177 174
178 // Apply shape factor for forbidden tran 175 // Apply shape factor for forbidden transitions
179 f *= corrections.ShapeFactor(betaType, p 176 f *= corrections.ShapeFactor(betaType, p, maxEnergy - ex);
180 sum += f + f0; << 177 sum += f;
181 cdf[i] = sum; 178 cdf[i] = sum;
182 f0 = f; <<
183 } 179 }
184 cdf[npti-1] = sum + f0; <<
185 } else { 180 } else {
186 for (G4int i = 0; i < npti; ++i) { cdf[i] 181 for (G4int i = 0; i < npti; ++i) { cdf[i] = 0.0; }
187 } 182 }
188 } 183 }
189 184
190 void G4BetaPlusDecay::DumpNuclearInfo() 185 void G4BetaPlusDecay::DumpNuclearInfo()
191 { 186 {
192 G4cout << " G4BetaPlusDecay " << fPrimaryIo 187 G4cout << " G4BetaPlusDecay " << fPrimaryIon->GetParticleName()
193 << " -> " << fResIon->GetParticleName() << 188 << " -> " << fResIon->GetParticleName() << " + " << fLepton->GetParticleName()
194 << " + " << fNeutrino->GetParticleName() << 189 << " + " << fNeutrino->GetParticleName() << " Eemax(MeV)="
195 << maxEnergy*eMass << " BR=" << GetBR() << 190 << maxEnergy*eMass << " BR=" << GetBR() << "%" << G4endl;
196 } 191 }
197 192