G4BENeutronChannel Class Reference

#include <G4BENeutronChannel.hh>

Inheritance diagram for G4BENeutronChannel:

Public Member Functions
	G4BENeutronChannel ()
virtual	~G4BENeutronChannel ()
virtual void	calculateProbability ()
G4DynamicParticle *	emit ()
G4double	sampleKineticEnergy ()
Public Member Functions inherited from G4BertiniEvaporationChannel
	G4BertiniEvaporationChannel ()
virtual	~G4BertiniEvaporationChannel ()
void	setVerboseLevel (G4int verbose)
void	setNucleusA (G4int inputA)
void	setNucleusZ (G4int inputZ)
G4int	getParticleA ()
G4int	getParticleZ ()
void	setExcitationEnergy (G4double inputE)
void	setQ (G4double inputQ)
void	setPairingCorrection (G4int isCorrection)
G4double	getLevelDensityParameter ()
G4String	getName ()
virtual G4double	getProbability ()
virtual void	setProbability (G4double newProb)
virtual void	calculateProbability ()=0
virtual G4double	qmFactor ()
virtual G4double	getQ ()
virtual G4double	getCoulomb ()
virtual G4double	getThresh ()
virtual G4DynamicParticle *	emit ()=0

Additional Inherited Members
Protected Member Functions inherited from G4BertiniEvaporationChannel
G4double	Q (G4double a, G4double z)
G4double	pairingEnergyProtons (G4int A)
G4double	pairingEnergyNeutrons (G4int N)
G4double	cameron (G4double a, G4double z)
G4double	cameronShellCorrectionP (G4int Z)
G4double	cameronShellCorrectionN (G4int N)
void	isotropicCosines (G4double &, G4double &, G4double &)
Protected Attributes inherited from G4BertiniEvaporationChannel
G4String	name
G4int	verboseLevel
G4int	nucleusA
G4int	nucleusZ
G4int	particleA
G4int	particleZ
G4double	exmass
G4double	emissionProbability
G4double	rho
G4double	correction
G4double	excitationEnergy
G4int	spin

Detailed Description

Definition at line 37 of file G4BENeutronChannel.hh.

Constructor & Destructor Documentation

G4BENeutronChannel()

G4BENeutronChannel::G4BENeutronChannel

(

)

Definition at line 47 of file G4BENeutronChannel.cc.

{
  name         = "neutron";
  particleA    = 1;
  particleZ    = 0;
  verboseLevel = 0;
  rho          = 0;
}

~G4BENeutronChannel()

G4BENeutronChannel::~G4BENeutronChannel ( )

virtual

Definition at line 57 of file G4BENeutronChannel.cc.

{
}

Member Function Documentation

calculateProbability()

void G4BENeutronChannel::calculateProbability ( )

virtual

Implements G4BertiniEvaporationChannel.

Definition at line 62 of file G4BENeutronChannel.cc.

{
  const G4int residualZ = nucleusZ - particleZ;
  const G4int residualA = nucleusA - particleA;
 
  if ( nucleusA  <  2.0 * particleA ||  
       nucleusZ  <  2.0 * particleZ ||  
       residualA <= residualZ       ||  
       excitationEnergy - getThresh() - correction < 0 )
    {
      if ( verboseLevel >= 6 )
    G4cout << "G4BENeutronChannel : calculateProbability = 0 " << G4endl;
      emissionProbability = 0;
      return;
    }
 
  // In HETC88 s-s0 was used in std::exp( s ), in which s0 was either 50 or
  // max(s_i), where i goes over all channels.
 
  const G4double levelParam = getLevelDensityParameter();
  
  const G4double slevel = 2 * std::sqrt( levelParam  * ( excitationEnergy - getThresh() - correction ) );
  const G4double eye0 = std::exp( slevel ) * ( slevel - 1 ) /  ( 2 * levelParam );
  const G4double eye1 = ( slevel*slevel - 3*slevel +3 ) * std::exp( slevel ) / ( 4 * levelParam*levelParam ) ;
  
  emissionProbability = std::pow( G4double(residualA), 0.666666 ) * alpha() * ( eye1 + beta() * eye0 );
  
  if ( verboseLevel >= 6 )
    G4cout << "G4BENeutronChannel : calculateProbability " << G4endl
       << "                    res A = " << residualA << G4endl 
       << "                    res Z = " << residualZ << G4endl 
       << "                    alpha = " << alpha() << G4endl 
       << "                     beta = " << beta() << G4endl
       << "                        E = " << excitationEnergy << G4endl
       << "               correction = " << correction << G4endl
       << "                     eye1 = " << eye1 << G4endl
       << "                     eye0 = " <<  eye0 << G4endl
       << "               levelParam = " << levelParam << G4endl
       << "                   thresh = " << getThresh() << G4endl
       << "                        s = " << s << G4endl
       << "              probability = " << emissionProbability << G4endl;
 
  return;
}

emit()

G4DynamicParticle * G4BENeutronChannel::emit ( )

virtual

Implements G4BertiniEvaporationChannel.

Definition at line 150 of file G4BENeutronChannel.cc.

{
  G4double u;
  G4double v;
  G4double w;
  G4DynamicParticle * pParticle = new G4DynamicParticle;
 
  pParticle -> SetDefinition( G4Neutron::Neutron() );
  pParticle -> SetKineticEnergy( sampleKineticEnergy() ); 
  isotropicCosines( u, v, w );
  pParticle -> SetMomentumDirection( u , v , w );  
 
  return pParticle;
}

sampleKineticEnergy()

G4double G4BENeutronChannel::sampleKineticEnergy

(

)

Definition at line 108 of file G4BENeutronChannel.cc.

{
  ////////////////
  // A random number is sampled from the density function
  // P(x) = x * std::exp ( 2 std::sqrt ( a ( xMax - x ) ) )  [not normalized],
  // x belongs to [ 0, xMax ]
  // with the 'Hit or Miss' -method
  // Kinetic energy is this energy scaled properly
  
  G4double levelParam;
  levelParam = getLevelDensityParameter();
  
  const G4double xMax  = excitationEnergy - getThresh() - correction + beta(); // maximum number
  const G4double xProb = ( - 1 + std::sqrt ( 1 + 4 * levelParam * xMax ) ) / ( 2 * levelParam ); // most probable value
  const G4double maxProb = xProb * std::exp ( 2 * std::sqrt ( levelParam * ( xMax - xProb ) ) ); // maximum value of P(x)
 
  // Sample x according to density function P(x) with rejection method
  G4double r1;
  G4double r2;
  G4int koe=0;
  do
    {
      r1 = beta() + G4UniformRand() * ( xMax - beta() );
      r2 = G4UniformRand() * maxProb;
      koe++;
    }
  while (  r1 * std::exp ( 2 * std::sqrt ( levelParam * ( xMax - r1 ) ) )  < r2 );
 
//  G4cout <<  koe << G4endl;
  G4double kineticEnergy = r1 - beta();
 
  if ( verboseLevel >= 10 )
    G4cout << " G4BENeutronChannel : sampleKineticEnergy() " << G4endl
       << "       kinetic n e = " << kineticEnergy << G4endl
       << "        levelParam = " << levelParam << G4endl
       << "             thresh= " << getThresh() << G4endl
       << "               beta= " << beta() << G4endl;
 
  return kineticEnergy;
}

Referenced by emit().

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

• G4BENeutronChannel.hh
• G4BENeutronChannel.cc