Geant4  10.03.p02
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G4INCLReflectionChannel.cc
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25 //
26 // INCL++ intra-nuclear cascade model
27 // Alain Boudard, CEA-Saclay, France
28 // Joseph Cugnon, University of Liege, Belgium
29 // Jean-Christophe David, CEA-Saclay, France
30 // Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
31 // Sylvie Leray, CEA-Saclay, France
32 // Davide Mancusi, CEA-Saclay, France
33 //
34 #define INCLXX_IN_GEANT4_MODE 1
35 
36 #include "globals.hh"
37 
39 #include "G4INCLFinalState.hh"
40 #include "G4INCLRandom.hh"
42 
43 #include <cmath>
44 
45 namespace G4INCL {
46  const G4double ReflectionChannel::sinMinReflectionAngleSquaredOverFour = std::pow(std::sin(2.*Math::pi/200.),2.);
47  const G4double ReflectionChannel::positionScalingFactor = 0.99;
48 
50  :theNucleus(n),theParticle(p)
51  {
52  }
53 
55  {
56  }
57 
59  fs->setTotalEnergyBeforeInteraction(theParticle->getEnergy() - theParticle->getPotentialEnergy());
60 
61  const ThreeVector &oldMomentum = theParticle->getMomentum();
62  const ThreeVector thePosition = theParticle->getPosition();
63  G4double pspr = thePosition.dot(oldMomentum);
64  if(pspr>=0) { // This means that the particle is trying to leave; perform a reflection
65  const G4double x2cour = thePosition.mag2();
66  const ThreeVector newMomentum = oldMomentum - (thePosition * (2.0 * pspr/x2cour));
67  const G4double deltaP2 = (newMomentum-oldMomentum).mag2();
68  theParticle->setMomentum(newMomentum);
69  const G4double minDeltaP2 = sinMinReflectionAngleSquaredOverFour * newMomentum.mag2();
70  if(deltaP2 < minDeltaP2) { // Avoid extremely small reflection angles
71  theParticle->setPosition(thePosition * positionScalingFactor);
72  INCL_DEBUG("Reflection angle for particle " << theParticle->getID() << " was too tangential: " << '\n'
73  << " " << deltaP2 << "=deltaP2<minDeltaP2=" << minDeltaP2 << '\n'
74  << " Resetting the particle position to ("
75  << thePosition.getX() << ", "
76  << thePosition.getY() << ", "
77  << thePosition.getZ() << ")" << '\n');
78  }
79  theNucleus->updatePotentialEnergy(theParticle);
80  } else { // The particle momentum is already directed towards the inside of the nucleus; do nothing
81  // ...but make sure this only happened because of the frozen propagation
82 // assert(theParticle->getPosition().dot(theParticle->getPropagationVelocity())>0.);
83  }
84 
85  theParticle->thawPropagation();
86  fs->addModifiedParticle(theParticle);
87  }
88 }
89 
void updatePotentialEnergy(Particle *p) const
Update the particle potential energy.
G4double dot(const ThreeVector &v) const
Abstract interface to the nuclear potential.
const char * p
Definition: xmltok.h:285
const G4double pi
void fillFinalState(FinalState *fs)
const G4INCL::ThreeVector & getMomentum() const
G4double getEnergy() const
void thawPropagation()
Unfreeze particle propagation.
G4double mag2() const
G4double getPotentialEnergy() const
Get the particle potential energy.
ReflectionChannel(Nucleus *n, Particle *p)
virtual void setPosition(const G4INCL::ThreeVector &position)
const G4int n
void setTotalEnergyBeforeInteraction(G4double E)
const G4INCL::ThreeVector & getPosition() const
G4double getX() const
double G4double
Definition: G4Types.hh:76
#define INCL_DEBUG(x)
void addModifiedParticle(Particle *p)
G4double getZ() const
long getID() const
virtual void setMomentum(const G4INCL::ThreeVector &momentum)
G4double getY() const