G4Neutron.cc

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// $Id$
//
// 
// ----------------------------------------------------------------------
//      GEANT 4 class implementation file
//
//      History: first implementation, based on object model of
//      4th April 1996, G.Cosmo
//                          H.Kurashige 7 July 1996
//      add neutron life time    Oct 17 2000 
// **********************************************************************
//  New impelemenataion as an utility class  M.Asai, 26 July 2004
// ----------------------------------------------------------------------
 
#include "G4Neutron.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "G4ParticleTable.hh"
 
#include "G4NeutronBetaDecayChannel.hh"
#include "G4DecayTable.hh"
 
// ######################################################################
// ###                           NEUTRON                              ###
// ######################################################################
G4Neutron* G4Neutron::theInstance = 0;
 
G4Neutron* G4Neutron::Definition()
{
  if (theInstance !=0) return theInstance;
  const G4String name = "neutron";
  // search in particle table]
  G4ParticleTable* pTable = G4ParticleTable::GetParticleTable();
  G4Ions* anInstance =  reinterpret_cast<G4Ions*>(pTable->FindParticle(name));
  if (anInstance ==0)
  {
  // create particle
  //
  //    Arguments for constructor are as follows
  //               name             mass          width         charge
  //             2*spin           parity  C-conjugation
  //          2*Isospin       2*Isospin3       G-parity
  //               type    lepton number  baryon number   PDG encoding
  //             stable         lifetime    decay table
  //             shortlived      subType    anti_encoding
  // use constants in CLHEP
  // static const double  neutron_mass_c2 = 939.56563 * MeV;
 
    anInstance = new G4Ions(
                 name, neutron_mass_c2, 7.467e-28*GeV,         0.0, 
            1,              +1,             0,          
            1,              -1,             0,             
         "baryon",               0,            +1,        2112,
        false,    885.7*second,          NULL,
        false,       "nucleon",             0,
                  0.0 
              );
    // Magnetic Moment
    G4double mN = eplus*hbar_Planck/2./(proton_mass_c2 /c_squared);
    anInstance->SetPDGMagneticMoment( -1.9130427 * mN);
    //create Decay Table 
    G4DecayTable* table = new G4DecayTable();
    // create a decay channel
    G4VDecayChannel* mode = new G4NeutronBetaDecayChannel("neutron",1.00);
    table->Insert(mode);
    anInstance->SetDecayTable(table);
    
  }
  theInstance = reinterpret_cast<G4Neutron*>(anInstance);
  return theInstance;
}
 
G4Neutron*  G4Neutron::NeutronDefinition()
{
  return Definition();
}
 
G4Neutron*  G4Neutron::Neutron()
{
  return Definition();
}