Geant4: G4NeutronBetaDecayChannel Class Reference

G4NeutronBetaDecayChannel::G4NeutronBetaDecayChannel	(	const G4String &	theParentName,
		G4double	theBR
	)

Definition at line 57 of file G4NeutronBetaDecayChannel.cc.

References G4cout, G4endl, G4VDecayChannel::GetVerboseLevel(), G4VDecayChannel::SetBR(), G4VDecayChannel::SetDaughter(), G4VDecayChannel::SetNumberOfDaughters(), and G4VDecayChannel::SetParent().

00060                    :G4VDecayChannel("Neutron Decay"),
00061                     aENuCorr(-0.102)
00062 {
00063   // set names for daughter particles
00064   if (theParentName == "neutron") {
00065     SetBR(theBR);
00066     SetParent("neutron");
00067     SetNumberOfDaughters(3);
00068     SetDaughter(0, "e-");
00069     SetDaughter(1, "anti_nu_e");
00070     SetDaughter(2, "proton");
00071   } else if (theParentName == "anti_neutron") {
00072     SetBR(theBR);
00073     SetParent("anti_neutron");
00074     SetNumberOfDaughters(3);
00075     SetDaughter(0, "e+");
00076     SetDaughter(1, "nu_e");
00077     SetDaughter(2, "anti_proton");
00078   } else {
00079 #ifdef G4VERBOSE
00080     if (GetVerboseLevel()>0) {
00081       G4cout << "G4NeutronBetaDecayChannel:: constructor :";
00082       G4cout << " parent particle is not neutron but ";
00083       G4cout << theParentName << G4endl;
00084     }
00085 #endif
00086   }
00087 }

G4NeutronBetaDecayChannel::~G4NeutronBetaDecayChannel ( ) [virtual]

Definition at line 89 of file G4NeutronBetaDecayChannel.cc.

00090 {
00091 }

G4NeutronBetaDecayChannel::G4NeutronBetaDecayChannel ( const G4NeutronBetaDecayChannel & ) [protected]

Definition at line 93 of file G4NeutronBetaDecayChannel.cc.

00094     : G4VDecayChannel(right),
00095       aENuCorr(-0.102)
00096 {
00097 }

G4NeutronBetaDecayChannel::G4NeutronBetaDecayChannel ( ) [protected]

Definition at line 51 of file G4NeutronBetaDecayChannel.cc.

00052                    :G4VDecayChannel(),
00053                     aENuCorr(-0.102)
00054 {
00055 }

G4DecayProducts * G4NeutronBetaDecayChannel::DecayIt ( G4double ) [virtual]

Implements G4VDecayChannel.

Definition at line 127 of file G4NeutronBetaDecayChannel.cc.

References aENuCorr, G4VDecayChannel::daughters, G4DecayProducts::DumpInfo(), G4VDecayChannel::FillDaughters(), G4VDecayChannel::FillParent(), G4cout, G4endl, G4UniformRand, G4ParticleDefinition::GetPDGMass(), G4VDecayChannel::GetVerboseLevel(), G4VDecayChannel::parent, and G4DecayProducts::PushProducts().

00128 {
00129   //  This class describes free neutron beta decay  kinemtics.
00130   //  This version neglects neutron/electron polarization  
00131   //  without Coulomb effect
00132 
00133 #ifdef G4VERBOSE
00134   if (GetVerboseLevel()>1) G4cout << "G4NeutronBetaDecayChannel::DecayIt ";
00135 #endif
00136 
00137   if (parent == 0) FillParent();  
00138   if (daughters == 0) FillDaughters();
00139  
00140   // parent mass
00141   G4double parentmass = parent->GetPDGMass();
00142 
00143   //daughters'mass
00144   G4double daughtermass[3]; 
00145   G4double sumofdaughtermass = 0.0;
00146   for (G4int index=0; index<3; index++){
00147     daughtermass[index] = daughters[index]->GetPDGMass();
00148     sumofdaughtermass += daughtermass[index];
00149   }
00150   G4double xmax = parentmass-sumofdaughtermass;  
00151 
00152    //create parent G4DynamicParticle at rest
00153   G4ThreeVector dummy;
00154   G4DynamicParticle * parentparticle = new G4DynamicParticle( parent, dummy, 0.0);
00155 
00156   //create G4Decayproducts
00157   G4DecayProducts *products = new G4DecayProducts(*parentparticle);
00158   delete parentparticle;
00159 
00160   // calculate daughter momentum
00161   G4double daughtermomentum[3];
00162 
00163   // calcurate electron energy
00164   G4double x;                    // Ee
00165   G4double p;                    // Pe
00166   G4double dm = daughtermass[0]; //Me
00167   G4double w;                    // cosine of e-nu angle
00168   G4double r;  
00169   G4double r0;
00170   do {
00171       x = xmax*G4UniformRand();
00172       p = std::sqrt(x*(x+2.0*dm));
00173       w = 1.0-2.0*G4UniformRand();
00174       r = p*(x+dm)*(xmax-x)*(xmax-x)*(1.0+aENuCorr*p/(x+dm)*w);
00175       r0 = G4UniformRand()*(xmax+dm)*(xmax+dm)*xmax*xmax*(1.0+aENuCorr);
00176   } while (r < r0);    
00177 
00178 
00179   //create daughter G4DynamicParticle 
00180   // rotation materix to lab frame
00181   G4double costheta = 2.*G4UniformRand()-1.0;
00182   G4double theta = std::acos(costheta)*rad;
00183   G4double phi  = twopi*G4UniformRand()*rad;
00184   G4RotationMatrix rm;
00185   rm.rotateY(theta);
00186   rm.rotateZ(phi);
00187 
00188   // daughter 0 (electron) in Z direction
00189   daughtermomentum[0] = p;
00190   G4ThreeVector direction0(0.0, 0.0, 1.0);
00191   direction0 = rm * direction0;
00192   G4DynamicParticle * daughterparticle0 
00193          = new G4DynamicParticle( daughters[0], direction0*daughtermomentum[0]);
00194   products->PushProducts(daughterparticle0);
00195 
00196   // daughter 1 (nutrino) in XZ plane
00197   G4double eNu;    // Enu
00198   eNu = (parentmass-daughtermass[2])*(parentmass+daughtermass[2])+(dm*dm)-2.*parentmass*(x+dm);
00199   eNu /= 2.*(parentmass+p*w-(x+dm));
00200   G4double cosn = w;
00201   G4double sinn = std::sqrt((1.0-cosn)*(1.0+cosn));
00202 
00203   G4ThreeVector direction1(sinn, 0.0, cosn);
00204   direction1 = rm * direction1;
00205   G4DynamicParticle * daughterparticle1 
00206          = new G4DynamicParticle( daughters[1], direction1*eNu);
00207   products->PushProducts(daughterparticle1);
00208 
00209   // daughter 2 (proton) at REST
00210   G4double eP;     // Eproton
00211   eP = parentmass-eNu-(x+dm)-daughtermass[2];
00212   G4double pPx = -eNu*sinn;
00213   G4double pPz = -p-eNu*cosn;
00214   G4double pP  = std::sqrt(eP*(eP+2.*daughtermass[2]));
00215   G4ThreeVector direction2(pPx/pP, 0.0, pPz/pP);
00216     G4DynamicParticle * daughterparticle2 
00217          = new G4DynamicParticle( daughters[2], direction2);
00218   products->PushProducts(daughterparticle2);
00219  
00220 
00221  // output message
00222 #ifdef G4VERBOSE
00223   if (GetVerboseLevel()>1) {
00224     G4cout << "G4NeutronBetaDecayChannel::DecayIt ";
00225     G4cout << "  create decay products in rest frame " <<G4endl;
00226     products->DumpInfo();
00227   }
00228 #endif
00229   return products;
00230 }

G4NeutronBetaDecayChannel & G4NeutronBetaDecayChannel::operator= ( const G4NeutronBetaDecayChannel & ) [protected]

Definition at line 100 of file G4NeutronBetaDecayChannel.cc.

References G4VDecayChannel::ClearDaughtersName(), G4VDecayChannel::daughters_name, G4VDecayChannel::kinematics_name, G4VDecayChannel::numberOfDaughters, G4VDecayChannel::parent_name, G4VDecayChannel::rbranch, and G4VDecayChannel::verboseLevel.

00101 {
00102   if (this != &right) { 
00103     kinematics_name = right.kinematics_name;
00104     verboseLevel = right.verboseLevel;
00105     rbranch = right.rbranch;
00106 
00107     // copy parent name
00108     parent_name = new G4String(*right.parent_name);
00109 
00110     // clear daughters_name array
00111     ClearDaughtersName();
00112 
00113     // recreate array
00114     numberOfDaughters = right.numberOfDaughters;
00115     if ( numberOfDaughters >0 ) {
00116       if (daughters_name !=0) ClearDaughtersName();
00117       daughters_name = new G4String*[numberOfDaughters];
00118       //copy daughters name
00119       for (G4int index=0; index < numberOfDaughters; index++) {
00120           daughters_name[index] = new G4String(*right.daughters_name[index]);
00121       }
00122     }
00123   }
00124   return *this;
00125 }

const G4double G4NeutronBetaDecayChannel::aENuCorr [protected]

Definition at line 70 of file G4NeutronBetaDecayChannel.hh.

Referenced by DecayIt().


Public Member Functions
	G4NeutronBetaDecayChannel (const G4String &theParentName, G4double theBR)
virtual	~G4NeutronBetaDecayChannel ()
virtual G4DecayProducts *	DecayIt (G4double)
Protected Member Functions
	G4NeutronBetaDecayChannel (const G4NeutronBetaDecayChannel &)
G4NeutronBetaDecayChannel &	operator= (const G4NeutronBetaDecayChannel &)
	G4NeutronBetaDecayChannel ()
Protected Attributes
const G4double	aENuCorr

G4NeutronBetaDecayChannel Class Reference

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation