MUSR: musrDecay Class Reference

00016 {
00017 
00018 
00019 
00020 
00021   //  G4cerr<<"METHOD CALLED WHEN SHOULD NOT BE AT ALL!!!!\n";//enable for geant code
00022   // The DecayIt() method returns by pointer a particle-change object.
00023   // Units are expressed in GEANT4 internal units.
00024   // get particle 
00025   const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
00026   G4ParticleDefinition* aParticleDef = aParticle->GetDefinition();
00027 
00028 
00029   // if particle is not a muon
00030   if(aParticle->GetDefinition()->GetParticleName()!="mu+")
00031         {
00032           G4ParticleChangeForDecay* k;
00033                     k = (G4ParticleChangeForDecay*)G4Decay::DecayIt(aTrack,aStep);
00034            return k ;
00035         }
00036   // m_ExtDecayer = 0;//G4Decay::GetExtDecayer();
00038 
00039   G4double p_time = aTrack.GetDynamicParticle()->GetPreAssignedDecayProperTime();
00040   G4double tp_time = aTrack.GetProperTime();
00041   m_RemainderLifeTime =p_time-tp_time;
00042   
00043   // check if  the particle is stable
00044   if (aParticleDef->GetPDGStable()) return &pParticleChangeForDecay ;
00045  
00046 
00047   //check if thePreAssignedDecayProducts exists
00048   const G4DecayProducts* o_products = (aParticle->GetPreAssignedDecayProducts());
00049   G4bool isPreAssigned = (o_products != 0);   
00050   G4DecayProducts* products = 0;
00051 
00052   // decay table
00053   G4DecayTable   *decaytable = aParticleDef->GetDecayTable();
00054  
00055   // check if external decayer exists
00056   G4bool isExtDecayer = (decaytable == 0);
00057 
00058   // Error due to NO Decay Table 
00059   if ( (decaytable == 0) && !isExtDecayer &&!isPreAssigned ){
00060 #ifdef G4VERBOSE
00061     if (GetVerboseLevel()>0) {
00062       G4cerr <<  "G4Decay::DoIt  : decay table not defined  for ";
00063       G4cerr << aParticle->GetDefinition()->GetParticleName()<< G4endl;
00064     }
00065 #endif
00066     pParticleChangeForDecay.SetNumberOfSecondaries(0);
00067     // Kill the parent particle
00068     pParticleChangeForDecay.ProposeTrackStatus( fStopAndKill ) ;
00069     pParticleChangeForDecay.ProposeLocalEnergyDeposit(0.0); 
00070     
00071     ClearNumberOfInteractionLengthLeft();
00072     return &pParticleChangeForDecay ;
00073   }
00074 
00075   if (isPreAssigned) {
00076     // copy decay products 
00077     products = new G4DecayProducts(*o_products); 
00078   }  else {
00079  
00080 
00081     //+++++++++++++++++++++++++++++++++++ACCORDING TO DECAY TABLE++++++++++++++++++++++++++
00082    // decay acoording to decay table
00083     // choose a decay channel
00084     G4VDecayChannel *decaychannel = decaytable->SelectADecayChannel();
00085     if (decaychannel == 0 ){
00086       // decay channel not found
00087       G4Exception("G4Decay::DoIt  : can not determine decay channel ");
00088     } else {
00089       G4int temp = decaychannel->GetVerboseLevel();
00090       // execute DecayIt() 
00091 #ifdef G4VERBOSE
00092       if (GetVerboseLevel()>1) {
00093         G4cerr << "G4Decay::DoIt  : selected decay channel  addr:" << decaychannel <<G4endl;
00094         decaychannel->SetVerboseLevel(GetVerboseLevel());
00095       }
00096 #endif
00097 
00098       //  CHECK FOR POLARIASATION AND ASSIGN IT TO THE DECAY METHOD
00099       
00100       G4ThreeVector parent_polarization = aParticle->GetPolarization();
00101       
00102       //-----------------------------INFORMATION---------------------------------
00103       //         G4cout <<"LEMuSRDecay MESSAGE:: polarization is " << parent_polarization <<" .\n";
00104       if(aParticle->GetDefinition()->GetParticleName()=="mu+")
00105         {
00106           musrMuonDecayChannel *muondecaychannel =new musrMuonDecayChannel("mu+",1.00);
00107           if(parent_polarization == G4ThreeVector(0,0,0))
00108             {  
00109               products = muondecaychannel->DecayIt(aParticle->GetMass());
00110             }
00111           if(parent_polarization != G4ThreeVector(0,0,0))
00112             {  
00113               products = muondecaychannel->DecayItPolarized(aParticle->GetMass(),parent_polarization);// has to be included in G4VDecayChannel.
00114             }
00115         }
00116       
00117       else products = decaychannel->DecayIt(aParticle->GetMass()) ;
00118       
00119       
00120       
00121 #ifdef G4VERBOSE
00122       if (GetVerboseLevel()>1) {
00123         decaychannel->SetVerboseLevel(temp);
00124       }
00125 #endif
00126 #ifdef G4VERBOSE
00127       // for debug
00128       //if (! products->IsChecked() ) products->DumpInfo();
00129 #endif
00130     }
00131   }
00132 
00133   // get parent particle information ...................................
00134   G4double   ParentEnergy  = aParticle->GetTotalEnergy();
00135   G4ThreeVector ParentDirection(aParticle->GetMomentumDirection());
00136 
00137   //boost all decay products to laboratory frame
00138   G4double energyDeposit = 0.0;
00139   G4double finalGlobalTime = aTrack.GetGlobalTime();
00140   if (aTrack.GetTrackStatus() == fStopButAlive ){
00141     // AtRest case
00142     finalGlobalTime += m_RemainderLifeTime;
00143     energyDeposit += aParticle->GetKineticEnergy();
00144     if (isPreAssigned) products->Boost( ParentEnergy, ParentDirection);
00145   } else {
00146     // PostStep case
00147     if (!isExtDecayer) products->Boost( ParentEnergy, ParentDirection);
00148   }
00149   //add products in pParticleChangeForDecay
00150   G4int numberOfSecondaries = products->entries();
00151 
00152   pParticleChangeForDecay.SetNumberOfSecondaries(numberOfSecondaries);
00153 
00154   //      G4cerr << "G4Decay::DoIt  : Decay vertex :";
00155   //    G4cerr << " Time: " << finalGlobalTime/ns << "[ns]";
00156   //    G4cerr << " X:" << (aTrack.GetPosition()).x() /cm << "[cm]";
00157   //    G4cerr << " Y:" << (aTrack.GetPosition()).y() /cm << "[cm]";
00158   //    G4cerr << " Z:" << (aTrack.GetPosition()).z() /cm << "[cm]";
00159   //    G4cerr << G4endl;
00160     //    products->DumpInfo();
00161 
00162   G4int index;
00163   G4ThreeVector currentPosition;
00164   const G4TouchableHandle thand = aTrack.GetTouchableHandle();
00165 
00166   for (index=0; index < numberOfSecondaries; index++)
00167   {
00168      // get current position of the track
00169      currentPosition = aTrack.GetPosition();
00170      // create a new track object
00171      G4Track* secondary = new G4Track( products->PopProducts(),
00172                                       finalGlobalTime ,
00173                                       currentPosition );
00174      // switch on good for tracking flag
00175      secondary->SetGoodForTrackingFlag();
00176      secondary->SetTouchableHandle(thand);
00177      // add the secondary track in the List
00178      pParticleChangeForDecay.AddSecondary(secondary);
00179   }
00180   delete products;
00181 
00182   // Kill the parent particle
00183   pParticleChangeForDecay.ProposeTrackStatus( fStopAndKill ) ;
00184   pParticleChangeForDecay.ProposeLocalEnergyDeposit(energyDeposit); 
00185   pParticleChangeForDecay.ProposeGlobalTime( finalGlobalTime );
00186   // reset NumberOfInteractionLengthLeft
00187   ClearNumberOfInteractionLengthLeft();
00188 
00189   return &pParticleChangeForDecay ;     
00190 
00191 }
musrDecay Class Reference

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation


Protected Member Functions
virtual G4VParticleChange *	DecayIt (const G4Track &aTrack, const G4Step &aStep)
Protected Attributes
G4ParticleChangeForDecay	pParticleChangeForDecay
G4double	m_RemainderLifeTime