| Geant4 Cross Reference |
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26
27 #include "G4LENDElastic.hh"
28 #include "G4Pow.hh"
29 #include "G4PhysicalConstants.hh"
30 #include "G4SystemOfUnits.hh"
31 #include "G4Nucleus.hh"
32 #include "G4IonTable.hh"
33
34 //extern "C" double MyRNG(void*) { return drand48(); }
35 //extern "C" double MyRNG(void*) { return CLHEP::HepRandom::getTheEngine()->flat(); }
36
37 G4HadFinalState * G4LENDElastic::ApplyYourself(const G4HadProjectile& aTrack, G4Nucleus& aTarg )
38 {
39
40 G4double temp = aTrack.GetMaterial()->GetTemperature();
41
42 //G4int iZ = int ( aTarg.GetZ() );
43 //G4int iA = int ( aTarg.GetN() );
44 //migrate to integer A and Z (GetN_asInt returns number of neutrons in the nucleus since this)
45 G4int iZ = aTarg.GetZ_asInt();
46 G4int iA = aTarg.GetA_asInt();
47 G4int iM = 0;
48 if ( aTarg.GetIsotope() != NULL ) {
49 iM = aTarg.GetIsotope()->Getm();
50 }
51
52 G4double ke = aTrack.GetKineticEnergy();
53
54 G4HadFinalState* theResult = &theParticleChange;
55 theResult->Clear();
56
57 G4GIDI_target* aTarget = get_target_from_map( lend_manager->GetNucleusEncoding( iZ , iA , iM ) );
58 if ( aTarget == NULL ) return returnUnchanged( aTrack , theResult );
59
60 G4double aMu = aTarget->getElasticFinalState( ke*MeV, temp, MyRNG , NULL );
61
62 G4double phi = twopi*G4UniformRand();
63 G4double theta = std::acos( aMu );
64 //G4double sinth = std::sin( theta );
65
66 G4ReactionProduct theNeutron( aTrack.GetDefinition() );
67 theNeutron.SetMomentum( aTrack.Get4Momentum().vect() );
68 theNeutron.SetKineticEnergy( ke );
69
70 //G4ParticleDefinition* pd = G4IonTable::GetIonTable()->GetIon( iZ , iA , iM );
71 //TK 170509 Fix for the case of excited isomer target
72 G4double EE = 0.0;
73 if ( iM != 0 ) {
74 G4LENDManager::GetInstance()->GetExcitationEnergyOfExcitedIsomer( iZ , iA , iM );
75 }
76 G4ParticleDefinition* target_pd = G4IonTable::GetIonTable()->GetIon( iZ , iA , EE );
77 G4ReactionProduct theTarget( target_pd );
78
79 G4double mass = target_pd->GetPDGMass();
80
81 // add Thermal motion
82 G4double kT = k_Boltzmann*temp;
83 G4ThreeVector v ( G4RandGauss::shoot() * std::sqrt( kT*mass )
84 , G4RandGauss::shoot() * std::sqrt( kT*mass )
85 , G4RandGauss::shoot() * std::sqrt( kT*mass ) );
86 theTarget.SetMomentum( v );
87
88 G4ThreeVector the3Neutron = theNeutron.GetMomentum();
89 G4double nEnergy = theNeutron.GetTotalEnergy();
90 G4ThreeVector the3Target = theTarget.GetMomentum();
91 G4double tEnergy = theTarget.GetTotalEnergy();
92 G4ReactionProduct theCMS;
93 G4double totE = nEnergy+tEnergy;
94 G4ThreeVector the3CMS = the3Target+the3Neutron;
95 theCMS.SetMomentum(the3CMS);
96 G4double cmsMom = std::sqrt(the3CMS*the3CMS);
97 G4double sqrts = std::sqrt((totE-cmsMom)*(totE+cmsMom));
98 theCMS.SetMass(sqrts);
99 theCMS.SetTotalEnergy(totE);
100
101 theNeutron.Lorentz(theNeutron, theCMS);
102 theTarget.Lorentz(theTarget, theCMS);
103 G4double en = theNeutron.GetTotalMomentum(); // already in CMS.
104 G4ThreeVector cms3Mom=theNeutron.GetMomentum(); // for neutron direction in CMS
105 G4double cms_theta=cms3Mom.theta();
106 G4double cms_phi=cms3Mom.phi();
107 G4ThreeVector tempVector;
108 tempVector.setX( std::cos(theta)*std::sin(cms_theta)*std::cos(cms_phi)
109 +std::sin(theta)*std::cos(phi)*std::cos(cms_theta)*std::cos(cms_phi)
110 -std::sin(theta)*std::sin(phi)*std::sin(cms_phi) );
111 tempVector.setY( std::cos(theta)*std::sin(cms_theta)*std::sin(cms_phi)
112 +std::sin(theta)*std::cos(phi)*std::cos(cms_theta)*std::sin(cms_phi)
113 +std::sin(theta)*std::sin(phi)*std::cos(cms_phi) );
114 tempVector.setZ( std::cos(theta)*std::cos(cms_theta)
115 -std::sin(theta)*std::cos(phi)*std::sin(cms_theta) );
116 tempVector *= en;
117 theNeutron.SetMomentum(tempVector);
118 theTarget.SetMomentum(-tempVector);
119 G4double tP = theTarget.GetTotalMomentum();
120 G4double tM = theTarget.GetMass();
121 theTarget.SetTotalEnergy(std::sqrt((tP+tM)*(tP+tM)-2.*tP*tM));
122
123
124 theNeutron.Lorentz(theNeutron, -1.*theCMS);
125 theTarget.Lorentz(theTarget, -1.*theCMS);
126
127 //110913 Add Protection for very low energy (1e-6eV) scattering
128 if ( theNeutron.GetKineticEnergy() <= 0 )
129 {
130 theNeutron.SetTotalEnergy ( theNeutron.GetMass() * ( 1 + G4Pow::GetInstance()->powA( 10 , -15.65 ) ) );
131 }
132
133 if ( theTarget.GetKineticEnergy() < 0 )
134 {
135 theTarget.SetTotalEnergy ( theTarget.GetMass() * ( 1 + G4Pow::GetInstance()->powA( 10 , -15.65 ) ) );
136 }
137 //110913 END
138
139 theResult->SetEnergyChange(theNeutron.GetKineticEnergy());
140 theResult->SetMomentumChange(theNeutron.GetMomentum().unit());
141 G4DynamicParticle* theRecoil = new G4DynamicParticle;
142
143 theRecoil->SetDefinition( target_pd );
144 theRecoil->SetMomentum( theTarget.GetMomentum() );
145 theResult->AddSecondary( theRecoil, secID );
146
147 return theResult;
148
149 }
150
151