G4RKPropagation Class Reference

#include <G4RKPropagation.hh>

Inheritance diagram for G4RKPropagation:

Public Member Functions
	G4RKPropagation ()
virtual	~G4RKPropagation ()
virtual void	Init (G4V3DNucleus *nucleus)
virtual void	Transport (G4KineticTrackVector &theActive, const G4KineticTrackVector &theSpectators, G4double theTimeStep)
G4bool	GetSphereIntersectionTimes (const G4KineticTrack *track, G4double &t1, G4double &t2)
G4ThreeVector	GetMomentumTransfer () const
G4double	GetBarrier (G4int encoding)
G4double	GetField (G4int encoding, G4ThreeVector pos)
Public Member Functions inherited from G4VFieldPropagation
	G4VFieldPropagation ()
virtual	~G4VFieldPropagation ()

Detailed Description

Definition at line 38 of file G4RKPropagation.hh.

Constructor & Destructor Documentation

G4RKPropagation::G4RKPropagation

(

)

Definition at line 80 of file G4RKPropagation.cc.

                                 :
theOuterRadius(0), theNucleus(0),
theFieldMap(0), theEquationMap(0),
theField(0)
{ }

G4RKPropagation::~G4RKPropagation ( )

virtual

Definition at line 87 of file G4RKPropagation.cc.

{
   // free theFieldMap memory
   if(theFieldMap) delete_FieldsAndMap(theFieldMap);

   // free theEquationMap memory
   if(theEquationMap) delete_EquationsAndMap(theEquationMap);

   if (theField) delete theField;
}

Member Function Documentation

G4double G4RKPropagation::GetBarrier ( G4int  encoding )

inline

Definition at line 84 of file G4RKPropagation.hh.

References encoding.

  {     
    std::map <G4int, G4VNuclearField *, std::less<G4int> >::iterator iter;
    iter = theFieldMap->find(encoding);
    if(iter == theFieldMap->end()) return 0;
    return (*theFieldMap)[encoding]->GetBarrier();
  }

G4double G4RKPropagation::GetField ( G4int  encoding, G4ThreeVector  pos  )

inline

Definition at line 92 of file G4RKPropagation.hh.

References encoding.

  {
    std::map <G4int, G4VNuclearField *, std::less<G4int> >::iterator iter;
    iter = theFieldMap->find(encoding);
    if(iter == theFieldMap->end()) return 0;
    return (*theFieldMap)[encoding]->GetField(pos);
  }

G4ThreeVector G4RKPropagation::GetMomentumTransfer ( ) const

virtual

Implements G4VFieldPropagation.

Definition at line 471 of file G4RKPropagation.cc.

{
   return theMomentumTranfer;
}

G4bool G4RKPropagation::GetSphereIntersectionTimes	(	const G4KineticTrack *	track,
		G4double &	t1,
		G4double &	t2
	)

Definition at line 607 of file G4RKPropagation.cc.

References python.hepunit::c_light, CLHEP::Hep3Vector::dot(), CLHEP::HepLorentzVector::e(), python.hepunit::fermi, G4KineticTrack::GetPosition(), G4KineticTrack::GetTrackingMomentum(), CLHEP::Hep3Vector::mag2(), and CLHEP::HepLorentzVector::vect().

Referenced by Transport().

{
   G4double radius = theOuterRadius + 3*fermi; // "safety" of 3 fermi
   G4ThreeVector speed = kt->GetTrackingMomentum().vect()/kt->GetTrackingMomentum().e(); // bost vector
   G4double scalarProd = kt->GetPosition().dot(speed);
   G4double speedMag2 = speed.mag2();
   G4double sqrtArg = scalarProd*scalarProd -
         speedMag2*(kt->GetPosition().mag2()-radius*radius);
   if(sqrtArg <= 0.) // particle will not intersect the sphere
   {
      return false;
   }
   t1 = (-scalarProd - std::sqrt(sqrtArg))/speedMag2/c_light;
   t2 = (-scalarProd + std::sqrt(sqrtArg))/speedMag2/c_light;
   return true;
}

void G4RKPropagation::Init ( G4V3DNucleus *  nucleus )

virtual

Implements G4VFieldPropagation.

Definition at line 99 of file G4RKPropagation.cc.

References G4AntiProton::AntiProton(), G4V3DNucleus::GetOuterRadius(), G4ParticleDefinition::GetPDGEncoding(), G4ParticleDefinition::GetPDGMass(), G4KaonMinus::KaonMinus(), G4KaonPlus::KaonPlus(), G4KaonZero::KaonZero(), G4Neutron::Neutron(), G4PionMinus::PionMinus(), G4PionPlus::PionPlus(), G4PionZero::PionZero(), G4Proton::Proton(), G4KM_OpticalEqRhs::SetFactor(), G4KM_NucleonEqRhs::SetMass(), G4SigmaMinus::SigmaMinus(), G4SigmaPlus::SigmaPlus(), and G4SigmaZero::SigmaZero().

{

   // free theFieldMap memory
   if(theFieldMap) delete_FieldsAndMap(theFieldMap);

   // free theEquationMap memory
   if(theEquationMap) delete_EquationsAndMap(theEquationMap);

   if (theField) delete theField;

   // Initialize the nuclear field map.
   theNucleus = nucleus;
   theOuterRadius = theNucleus->GetOuterRadius();

   theFieldMap = new std::map <G4int, G4VNuclearField*, std::less<G4int> >;

   (*theFieldMap)[G4Proton::Proton()->GetPDGEncoding()] = new G4ProtonField(theNucleus);
   (*theFieldMap)[G4Neutron::Neutron()->GetPDGEncoding()] = new G4NeutronField(theNucleus);
   (*theFieldMap)[G4AntiProton::AntiProton()->GetPDGEncoding()] = new G4AntiProtonField(theNucleus);
   (*theFieldMap)[G4KaonPlus::KaonPlus()->GetPDGEncoding()] = new G4KaonPlusField(theNucleus);
   (*theFieldMap)[G4KaonMinus::KaonMinus()->GetPDGEncoding()] = new G4KaonMinusField(theNucleus);
   (*theFieldMap)[G4KaonZero::KaonZero()->GetPDGEncoding()] = new G4KaonZeroField(theNucleus);
   (*theFieldMap)[G4PionPlus::PionPlus()->GetPDGEncoding()] = new G4PionPlusField(theNucleus);
   (*theFieldMap)[G4PionMinus::PionMinus()->GetPDGEncoding()] = new G4PionMinusField(theNucleus);
   (*theFieldMap)[G4PionZero::PionZero()->GetPDGEncoding()] = new G4PionZeroField(theNucleus);
   (*theFieldMap)[G4SigmaPlus::SigmaPlus()->GetPDGEncoding()] = new G4SigmaPlusField(theNucleus);
   (*theFieldMap)[G4SigmaMinus::SigmaMinus()->GetPDGEncoding()] = new G4SigmaMinusField(theNucleus);
   (*theFieldMap)[G4SigmaZero::SigmaZero()->GetPDGEncoding()] = new G4SigmaZeroField(theNucleus);

   theEquationMap = new std::map <G4int, G4Mag_EqRhs*, std::less<G4int> >;

   // theField needed by the design of G4Mag_eqRhs
   theField = new G4KM_DummyField;      //Field not needed for integration
   G4KM_OpticalEqRhs * opticalEq;
   G4KM_NucleonEqRhs * nucleonEq;
   G4double mass;
   G4double opticalCoeff;

   nucleonEq = new G4KM_NucleonEqRhs(theField, theNucleus);
   mass = G4Proton::Proton()->GetPDGMass();
   nucleonEq->SetMass(mass);
   (*theEquationMap)[G4Proton::Proton()->GetPDGEncoding()] = nucleonEq;

   nucleonEq = new G4KM_NucleonEqRhs(theField, theNucleus);
   mass = G4Neutron::Neutron()->GetPDGMass();
   nucleonEq->SetMass(mass);
   (*theEquationMap)[G4Neutron::Neutron()->GetPDGEncoding()] = nucleonEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4AntiProton::AntiProton()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4AntiProton::AntiProton()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4AntiProton::AntiProton()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4KaonPlus::KaonPlus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4KaonPlus::KaonPlus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4KaonPlus::KaonPlus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4KaonMinus::KaonMinus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4KaonMinus::KaonMinus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4KaonMinus::KaonMinus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4KaonZero::KaonZero()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4KaonZero::KaonZero()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4KaonZero::KaonZero()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4PionPlus::PionPlus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4PionPlus::PionPlus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4PionPlus::PionPlus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4PionMinus::PionMinus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4PionMinus::PionMinus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4PionMinus::PionMinus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4PionZero::PionZero()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4PionZero::PionZero()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4PionZero::PionZero()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4SigmaPlus::SigmaPlus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4SigmaPlus::SigmaPlus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4SigmaPlus::SigmaPlus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4SigmaMinus::SigmaMinus()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4SigmaMinus::SigmaMinus()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4SigmaMinus::SigmaMinus()->GetPDGEncoding()] = opticalEq;

   opticalEq = new G4KM_OpticalEqRhs(theField, theNucleus);
   mass = G4SigmaZero::SigmaZero()->GetPDGMass();
   opticalCoeff =
         (*theFieldMap)[G4SigmaZero::SigmaZero()->GetPDGEncoding()]->GetCoeff();
   opticalEq->SetFactor(mass,opticalCoeff);
   (*theEquationMap)[G4SigmaZero::SigmaZero()->GetPDGEncoding()] = opticalEq;
}

void G4RKPropagation::Transport ( G4KineticTrackVector &  theActive, const G4KineticTrackVector &  theSpectators, G4double  theTimeStep  )

virtual

Implements G4VFieldPropagation.

Definition at line 223 of file G4RKPropagation.cc.

References G4KineticTrack::captured, DBL_MAX, CLHEP::HepLorentzVector::e(), G4cerr, G4cout, G4endl, G4KineticTrack::GetActualMass(), G4KineticTrack::GetDefinition(), G4VNuclearField::GetField(), G4V3DNucleus::GetMass(), G4ParticleDefinition::GetPDGEncoding(), G4KineticTrack::GetPosition(), G4KineticTrack::GetProjectilePotential(), GetSphereIntersectionTimes(), G4KineticTrack::GetState(), G4KineticTrack::GetTrackingMomentum(), G4KineticTrack::gone_out, G4KineticTrack::inside, CLHEP::HepLorentzVector::mag(), G4KineticTrack::miss_nucleus, G4Neutron::Neutron(), G4KineticTrack::outside, G4Proton::Proton(), G4KineticTrack::SetState(), G4KineticTrack::SetTrackingMomentum(), sqr(), CLHEP::Hep3Vector::unit(), and CLHEP::HepLorentzVector::vect().

{
   //  reset momentum transfer to field
   theMomentumTranfer=G4ThreeVector(0,0,0);

   // Loop over tracks

   std::vector<G4KineticTrack *>::iterator i;
   for(i = active.begin(); i != active.end(); ++i)
   {
      G4double currTimeStep = timeStep;
      G4KineticTrack * kt = *i;
      G4int encoding = kt->GetDefinition()->GetPDGEncoding();

      std::map <G4int, G4VNuclearField*, std::less<G4int> >::iterator fieldIter= theFieldMap->find(encoding);

      G4VNuclearField* currentField=0;
      if ( fieldIter != theFieldMap->end() ) currentField=fieldIter->second;

      // debug
      //    if ( timeStep > 1e30 ) {
      //    G4cout << " Name :" << kt->GetDefinition()->GetParticleName() << G4endl;
      //    }

      // Get the time of intersections with the nucleus surface.
      G4double t_enter, t_leave;
      // if the particle does not intersecate with the nucleus go to next particle
      if(!GetSphereIntersectionTimes(kt, t_enter, t_leave))
      {
         kt->SetState(G4KineticTrack::miss_nucleus);
         continue;
      }


#ifdef debug_1_RKPropagation
      G4cout <<" kt,timeStep, Intersection times tenter, tleave  "
            <<kt<< " / state= " <<kt->GetState() <<" / " <<" "<< currTimeStep << " / " << t_enter << " / " << t_leave <<G4endl;
#endif

      // if the particle is already outside nucleus go to next  @@GF should never happen? check!
      //  does happen for particles added as late....
      //     if(t_leave < 0 )
      //     {
      //        throw G4HadronicException(__FILE__, __LINE__, "G4RKPropagation:: Attempt to track particle past a  nucleus");
      //        continue;
      //     }

      // Apply a straight line propagation for particle types
      // not included in the model
      if( ! currentField )
      {
         if(currTimeStep == DBL_MAX)currTimeStep = t_leave*1.05;
         FreeTransport(kt, currTimeStep);
         if ( currTimeStep >= t_leave )
         {
            if ( kt->GetState() == G4KineticTrack::inside )
            { kt->SetState(G4KineticTrack::gone_out); }
            else
            { kt->SetState(G4KineticTrack::miss_nucleus);}
         } else if (kt->GetState() == G4KineticTrack::outside && currTimeStep >= t_enter ){
            kt->SetState(G4KineticTrack::inside);
         }

         continue;
      }

      if(t_enter > 0)  // the particle is out. Transport free to the surface
      {
         if(t_enter > currTimeStep)  // the particle won't enter the nucleus
         {
            FreeTransport(kt, currTimeStep);
            continue;
         }
         else
         {
            FreeTransport(kt, t_enter);   // go to surface
            currTimeStep -= t_enter;
            t_leave      -= t_enter;  // time left to leave nucleus
            // on the surface the particle loose the barrier energy
            //  G4double newE = mom.e()-(*theFieldMap)[encoding]->GetBarrier();
            //     GetField = Barrier + FermiPotential
            G4double newE = kt->GetTrackingMomentum().e()-currentField->GetField(kt->GetPosition());

            if(newE <= kt->GetActualMass())  // the particle cannot enter the nucleus
            {
               // FixMe: should be "pushed back?"
               //      for the moment take it past the nucleus, so we'll not worry next time..
               FreeTransport(kt, 1.1*t_leave);   // take past nucleus
               kt->SetState(G4KineticTrack::miss_nucleus);
               //      G4cout << "G4RKPropagation: Warning particle cannot enter Nucleus :" << G4endl;
               //      G4cout << " enter nucleus, E out/in: " << kt->GetTrackingMomentum().e() << " / " << newE <<G4endl;
               //      G4cout << " the Field "<< currentField->GetField(kt->GetPosition()) << " "<< kt->GetPosition()<<G4endl;
               //      G4cout << " the particle "<<kt->GetDefinition()->GetParticleName()<<G4endl;
               continue;
            }
            //
            G4double newP = std::sqrt(newE*newE- sqr(kt->GetActualMass()));
            G4LorentzVector new4Mom(newP*kt->GetTrackingMomentum().vect().unit(), newE);
            G4ThreeVector transfer(kt->GetTrackingMomentum().vect()-new4Mom.vect());
            G4ThreeVector boost= transfer / std::sqrt(transfer.mag2() + sqr(theNucleus->GetMass()));
            new4Mom*=G4LorentzRotation(boost);
            kt->SetTrackingMomentum(new4Mom);
            kt->SetState(G4KineticTrack::inside);

            /*
     G4cout <<" Enter Nucleus - E/Field/Sum: " <<kt->GetTrackingMomentum().e() << " / "
           << (*theFieldMap)[encoding]->GetField(kt->GetPosition()) << " / "
       << kt->GetTrackingMomentum().e()-currentField->GetField(kt->GetPosition())
       << G4endl
       << " Barrier / field just inside nucleus (0.9999*kt->GetPosition())"
       << (*theFieldMap)[encoding]->GetBarrier() << " / "
       << (*theFieldMap)[encoding]->GetField(0.9999*kt->GetPosition())
       << G4endl;
             */
         }
      }

      // FixMe: should I add a control on theCutOnP here?
      // Transport the particle into the nucleus
      //       G4cerr << "RKPropagation t_leave, curTimeStep " <<t_leave << " " <<currTimeStep<<G4endl;
      G4bool is_exiting=false;
      if(currTimeStep > t_leave)  // particle will exit from the nucleus
      {
         currTimeStep = t_leave;
         is_exiting=true;
      }

#ifdef debug_1_RKPropagation
      G4cerr << "RKPropagation is_exiting?, t_leave, curTimeStep " <<is_exiting<<" "<<t_leave << " " <<currTimeStep<<G4endl;
      G4cout << "RKPropagation Ekin, field, projectile potential, p "
            << kt->GetTrackingMomentum().e() - kt->GetTrackingMomentum().mag() << " "
            << kt->GetPosition()<<" "
            << G4endl << currentField->GetField(kt->GetPosition()) << " "
            <<  kt->GetProjectilePotential()<< G4endl
            << kt->GetTrackingMomentum()
            << G4endl;
#endif

      G4LorentzVector momold=kt->GetTrackingMomentum();
      G4ThreeVector posold=kt->GetPosition();

      //    if (currentField->GetField(kt->GetPosition()) > kt->GetProjectilePotential() ||
      if (currTimeStep > 0 &&
            ! FieldTransport(kt, currTimeStep)) {
         FreeTransport(kt,currTimeStep);
      }

#ifdef debug_1_RKPropagation
      G4cout << "RKPropagation Ekin, field, p "
            << kt->GetTrackingMomentum().e() - kt->GetTrackingMomentum().mag() << " "
            << G4endl << currentField->GetField(kt->GetPosition())<< G4endl
            << kt->GetTrackingMomentum()
            << G4endl
            << "delta p " << momold-kt->GetTrackingMomentum() << G4endl
            << "del pos " << posold-kt->GetPosition()
            << G4endl;
#endif

      // complete the transport
      // FixMe: in some cases there could be a significant
      //        part to do still in the nucleus, or we stepped to far... depending on
      //        slope of potential
      G4double t_in=-1, t_out=0;  // set onto boundary.

      // should go out, or are already out by a too long step..
      if(is_exiting ||
            (GetSphereIntersectionTimes(kt, t_in, t_out) &&t_in<0 && t_out<=0 ))  // particle is exiting
      {
         if(t_in < 0 && t_out >= 0)   //still inside, transport safely out.
         {
            // transport free to a position that is surely out of the nucleus, to avoid
            // a new transportation and a new adding the barrier next loop.
            G4ThreeVector savePos = kt->GetPosition();
            FreeTransport(kt, t_out);
            // and evaluate the right the energy
            G4double newE=kt->GetTrackingMomentum().e();

            //  G4cout << " V pos/savePos << "
            //      << (*theFieldMap)[encoding]->GetField(kt->GetPosition())<< " / "
            //      << (*theFieldMap)[encoding]->GetField(savePos)
            //      << G4endl;

            if ( std::abs(currentField->GetField(savePos)) > 0. &&
                  std::abs(currentField->GetField(kt->GetPosition())) > 0.)
            { // FixMe GF: savePos/pos may be out of nucleus, where GetField(..)=0
               //           This wrongly adds or subtracts the Barrier here while
               //           this is done later.
               newE += currentField->GetField(savePos)
                                  - currentField->GetField(kt->GetPosition());
            }

            //       G4cout << " go border nucleus, E in/border: " << kt->GetTrackingMomentum() << " / " << newE <<G4endl;

            if(newE < kt->GetActualMass())
            {
#ifdef debug_1_RKPropagation
               G4cout << "RKPropagation-Transport: problem with particle exiting - ignored" << G4endl;
               G4cout << " cannot leave nucleus, E in/out: " << kt->GetTrackingMomentum() << " / " << newE <<G4endl;
#endif
               if (kt->GetDefinition() == G4Proton::Proton() ||
                     kt->GetDefinition() == G4Neutron::Neutron() ) {
                  kt->SetState(G4KineticTrack::captured);
               } else {
                  kt->SetState(G4KineticTrack::gone_out);  //@@GF tofix
               }
               continue; // the particle cannot exit the nucleus
            }
            G4double newP = std::sqrt(newE*newE- sqr(kt->GetActualMass()));
            G4LorentzVector new4Mom(newP*kt->GetTrackingMomentum().vect().unit(), newE);
            G4ThreeVector transfer(kt->GetTrackingMomentum().vect()-new4Mom.vect());
            G4ThreeVector boost= transfer / std::sqrt(transfer.mag2() + sqr(theNucleus->GetMass()));
            new4Mom*=G4LorentzRotation(boost);
            kt->SetTrackingMomentum(new4Mom);
         }
         // add the potential barrier
         // FixMe the Coulomb field is not parallel to mom, this is simple approximation
         G4double newE = kt->GetTrackingMomentum().e()+currentField->GetField(kt->GetPosition());
         if(newE < kt->GetActualMass())
         {  // the particle cannot exit the nucleus  @@@ GF check.
#ifdef debug_1_RKPropagation
            G4cout << " cannot leave nucleus, E in/out: " << kt->GetTrackingMomentum() << " / " << newE <<G4endl;
#endif
            if (kt->GetDefinition() == G4Proton::Proton() ||
                  kt->GetDefinition() == G4Neutron::Neutron() ) {
               kt->SetState(G4KineticTrack::captured);
            } else {
               kt->SetState(G4KineticTrack::gone_out);  //@@GF tofix
            }
            continue;
         }
         G4double newP = std::sqrt(newE*newE- sqr(kt->GetActualMass()));
         G4LorentzVector new4Mom(newP*kt->GetTrackingMomentum().vect().unit(), newE);
         G4ThreeVector transfer(kt->GetTrackingMomentum().vect()-new4Mom.vect());
         G4ThreeVector boost= transfer / std::sqrt(transfer.mag2() + sqr(theNucleus->GetMass()));
         new4Mom*=G4LorentzRotation(boost);
         kt->SetTrackingMomentum(new4Mom);
         kt->SetState(G4KineticTrack::gone_out);
      }

   }

}

---

The documentation for this class was generated from the following files:

• G4RKPropagation.hh
• G4RKPropagation.cc