Gabriele Cosmo
403 lines
14 KiB
C++
403 lines
14 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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//
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// $Id: G4Decay.cc,v 1.21 2005/11/21 18:06:07 asaim Exp $
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// GEANT4 tag $Name: geant4-08-00 $
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//
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//
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// --------------------------------------------------------------
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// GEANT 4 class implementation file
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//
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// History: first implementation, based on object model of
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// 2nd December 1995, G.Cosmo
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// 7 July 1996 H.Kurashige
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// ------------------------------------------------------------
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// remove BuildPhysicsTable() 28 Nov. 1997 H.Kurashige
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// change DBL_EPSIRON to DBL_MIN 14 Dec. 1997 H.Kurashige
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// modified for new ParticleChange 12 Mar. 1998 H.Kurashige
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// modified for "GoodForTrackingFlag" 19 June 1998 H.Kurashige
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// rename thePhysicsTable to aPhyscisTable 2 Aug. 1998 H.Kurashige
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// modified IsApplicable in order to protect the decay from registered
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// to resonances 12 Dec. 1998 H.Kurashige
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// remove G4ParticleMomentum 6 Feb. 99 H.Kurashige
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// modified IsApplicable to activate G4Decay for resonances 1 Mar. 00 H.Kurashige
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// Add External Decayer 23 Feb. 2001 H.Kurashige
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// change LowestBinValue,HighestBinValue and TotBin(200) 9 Feb. 2002
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//
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#include "G4Decay.hh"
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#include "G4DynamicParticle.hh"
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#include "G4DecayProducts.hh"
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#include "G4DecayTable.hh"
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#include "G4PhysicsLogVector.hh"
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#include "G4ParticleChangeForDecay.hh"
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#include "G4VExtDecayer.hh"
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// constructor
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G4Decay::G4Decay(const G4String& processName)
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:G4VRestDiscreteProcess(processName, fDecay),
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verboseLevel(1),
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HighestValue(20.0),
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pExtDecayer(0)
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{
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>1) {
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G4cerr << "G4Decay constructor " << " Name:" << processName << G4endl;
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}
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#endif
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pParticleChange = &fParticleChangeForDecay;
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}
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G4Decay::~G4Decay()
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{
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if (pExtDecayer) {
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delete pExtDecayer;
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}
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}
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G4bool G4Decay::IsApplicable(const G4ParticleDefinition& aParticleType)
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{
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// check if the particle is stable?
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if (aParticleType.GetPDGLifeTime() <0.0) {
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return false;
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} else if (aParticleType.GetPDGMass() <= 0.0*MeV) {
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return false;
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} else {
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return true;
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}
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}
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G4double G4Decay::GetMeanLifeTime(const G4Track& aTrack ,
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G4ForceCondition*)
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{
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// returns the mean free path in GEANT4 internal units
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G4double meanlife;
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// get particle
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const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
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G4ParticleDefinition* aParticleDef = aParticle->GetDefinition();
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G4double aLife = aParticleDef->GetPDGLifeTime();
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// check if the particle is stable?
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if (aParticleDef->GetPDGStable()) {
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meanlife = DBL_MAX;
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} else {
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meanlife = aLife;
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}
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>1) {
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G4cout << "mean life time: "<< meanlife/ns << "[ns]" << G4endl;
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}
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#endif
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return meanlife;
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}
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G4double G4Decay::GetMeanFreePath(const G4Track& aTrack,G4double, G4ForceCondition*)
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{
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// get particle
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const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
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G4ParticleDefinition* aParticleDef = aParticle->GetDefinition();
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G4double aMass = aParticle->GetMass();
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G4double aLife = aParticleDef->GetPDGLifeTime();
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// returns the mean free path in GEANT4 internal units
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G4double pathlength;
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G4double aCtau = c_light * aLife;
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// check if the particle is stable?
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if (aParticleDef->GetPDGStable()) {
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pathlength = DBL_MAX;
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//check if the particle has very short life time ?
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} else if (aCtau < DBL_MIN) {
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pathlength = DBL_MIN;
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} else {
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//calculate the mean free path
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// by using normalized kinetic energy (= Ekin/mass)
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G4double rKineticEnergy = aParticle->GetKineticEnergy()/aMass;
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if ( rKineticEnergy > HighestValue) {
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// gamma >> 1
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pathlength = ( rKineticEnergy + 1.0)* aCtau;
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} else if ( rKineticEnergy < DBL_MIN ) {
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// too slow particle
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>1) {
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G4cerr << "G4Decay::GetMeanFreePath() !!particle stops!!";
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G4cerr << aParticleDef->GetParticleName() << G4endl;
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G4cerr << "KineticEnergy:" << aParticle->GetKineticEnergy()/GeV <<"[GeV]";
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}
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#endif
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pathlength = DBL_MIN;
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} else {
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// beta <1
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pathlength = (aParticle->GetTotalMomentum())/aMass*aCtau ;
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}
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}
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return pathlength;
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}
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void G4Decay::BuildPhysicsTable(const G4ParticleDefinition&)
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{
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return;
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}
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G4VParticleChange* G4Decay::DecayIt(const G4Track& aTrack, const G4Step& )
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{
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// The DecayIt() method returns by pointer a particle-change object.
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// Units are expressed in GEANT4 internal units.
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// Initialize ParticleChange
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// all members of G4VParticleChange are set to equal to
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// corresponding member in G4Track
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fParticleChangeForDecay.Initialize(aTrack);
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// get particle
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const G4DynamicParticle* aParticle = aTrack.GetDynamicParticle();
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G4ParticleDefinition* aParticleDef = aParticle->GetDefinition();
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// check if the particle is stable
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if (aParticleDef->GetPDGStable()) return &fParticleChangeForDecay ;
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//check if thePreAssignedDecayProducts exists
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const G4DecayProducts* o_products = (aParticle->GetPreAssignedDecayProducts());
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G4bool isPreAssigned = (o_products != 0);
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G4DecayProducts* products = 0;
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// decay table
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G4DecayTable *decaytable = aParticleDef->GetDecayTable();
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// check if external decayer exists
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G4bool isExtDecayer = (decaytable == 0) && (pExtDecayer !=0);
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// Error due to NO Decay Table
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if ( (decaytable == 0) && !isExtDecayer &&!isPreAssigned ){
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>0) {
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G4cerr << "G4Decay::DoIt : decay table not defined for ";
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G4cerr << aParticle->GetDefinition()->GetParticleName()<< G4endl;
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}
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#endif
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fParticleChangeForDecay.SetNumberOfSecondaries(0);
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// Kill the parent particle
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fParticleChangeForDecay.ProposeTrackStatus( fStopAndKill ) ;
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fParticleChangeForDecay.ProposeLocalEnergyDeposit(0.0);
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ClearNumberOfInteractionLengthLeft();
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return &fParticleChangeForDecay ;
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}
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if (isPreAssigned) {
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// copy decay products
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products = new G4DecayProducts(*o_products);
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} else if ( isExtDecayer ) {
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// decay according to external decayer
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products = pExtDecayer->ImportDecayProducts(aTrack);
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} else {
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// decay acoording to decay table
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// choose a decay channel
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G4VDecayChannel *decaychannel = decaytable->SelectADecayChannel();
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if (decaychannel == 0 ){
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// decay channel not found
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G4Exception("G4Decay::DoIt : can not determine decay channel ");
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} else {
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// execute DecayIt()
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#ifdef G4VERBOSE
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G4int temp = decaychannel->GetVerboseLevel();
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if (GetVerboseLevel()>1) {
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G4cerr << "G4Decay::DoIt : selected decay channel addr:" << decaychannel <<G4endl;
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decaychannel->SetVerboseLevel(GetVerboseLevel());
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}
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#endif
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products = decaychannel->DecayIt(aParticle->GetMass());
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>1) {
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decaychannel->SetVerboseLevel(temp);
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}
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#endif
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#ifdef G4VERBOSE
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// for debug
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//if (! products->IsChecked() ) products->DumpInfo();
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#endif
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}
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}
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// get parent particle information ...................................
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G4double ParentEnergy = aParticle->GetTotalEnergy();
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G4ThreeVector ParentDirection(aParticle->GetMomentumDirection());
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//boost all decay products to laboratory frame
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G4double energyDeposit = 0.0;
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G4double finalGlobalTime = aTrack.GetGlobalTime();
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if (aTrack.GetTrackStatus() == fStopButAlive ){
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// AtRest case
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finalGlobalTime += fRemainderLifeTime;
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energyDeposit += aParticle->GetKineticEnergy();
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if (isPreAssigned) products->Boost( ParentEnergy, ParentDirection);
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} else {
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// PostStep case
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if (!isExtDecayer) products->Boost( ParentEnergy, ParentDirection);
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}
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//add products in fParticleChangeForDecay
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G4int numberOfSecondaries = products->entries();
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fParticleChangeForDecay.SetNumberOfSecondaries(numberOfSecondaries);
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>1) {
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G4cerr << "G4Decay::DoIt : Decay vertex :";
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G4cerr << " Time: " << finalGlobalTime/ns << "[ns]";
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G4cerr << " X:" << (aTrack.GetPosition()).x() /cm << "[cm]";
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G4cerr << " Y:" << (aTrack.GetPosition()).y() /cm << "[cm]";
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G4cerr << " Z:" << (aTrack.GetPosition()).z() /cm << "[cm]";
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G4cerr << G4endl;
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G4cerr << "G4Decay::DoIt : decay products in Lab. Frame" << G4endl;
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products->DumpInfo();
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}
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#endif
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G4int index;
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G4ThreeVector currentPosition;
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const G4TouchableHandle thand = aTrack.GetTouchableHandle();
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for (index=0; index < numberOfSecondaries; index++)
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{
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// get current position of the track
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currentPosition = aTrack.GetPosition();
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// create a new track object
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G4Track* secondary = new G4Track( products->PopProducts(),
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finalGlobalTime ,
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currentPosition );
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// switch on good for tracking flag
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secondary->SetGoodForTrackingFlag();
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secondary->SetTouchableHandle(thand);
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// add the secondary track in the List
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fParticleChangeForDecay.AddSecondary(secondary);
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}
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delete products;
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// Kill the parent particle
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fParticleChangeForDecay.ProposeTrackStatus( fStopAndKill ) ;
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fParticleChangeForDecay.ProposeLocalEnergyDeposit(energyDeposit);
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fParticleChangeForDecay.ProposeGlobalTime( finalGlobalTime );
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// Clear NumberOfInteractionLengthLeft
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ClearNumberOfInteractionLengthLeft();
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return &fParticleChangeForDecay ;
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}
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void G4Decay::StartTracking(G4Track*)
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{
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currentInteractionLength = -1.0;
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ResetNumberOfInteractionLengthLeft();
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fRemainderLifeTime = -1.0;
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}
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void G4Decay::EndTracking()
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{
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// Clear NumberOfInteractionLengthLeft
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ClearNumberOfInteractionLengthLeft();
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currentInteractionLength = -1.0;
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}
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G4double G4Decay::PostStepGetPhysicalInteractionLength(
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const G4Track& track,
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G4double previousStepSize,
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G4ForceCondition* condition
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)
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{
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// condition is set to "Not Forced"
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*condition = NotForced;
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// pre-assigned Decay time
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G4double pTime = track.GetDynamicParticle()->GetPreAssignedDecayProperTime();
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G4double aLife = track.GetDynamicParticle()->GetDefinition()->GetPDGLifeTime();
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if (pTime < 0.) {
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// normal case
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if ( previousStepSize > 0.0){
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// subtract NumberOfInteractionLengthLeft
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SubtractNumberOfInteractionLengthLeft(previousStepSize);
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if(theNumberOfInteractionLengthLeft<0.){
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theNumberOfInteractionLengthLeft=perMillion;
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}
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fRemainderLifeTime = theNumberOfInteractionLengthLeft*aLife;
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}
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// get mean free path
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currentInteractionLength = GetMeanFreePath(track, previousStepSize, condition);
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#ifdef G4VERBOSE
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if ((currentInteractionLength <=0.0) || (verboseLevel>2)){
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G4cout << "G4Decay::PostStepGetPhysicalInteractionLength " << G4endl;
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track.GetDynamicParticle()->DumpInfo();
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G4cout << " in Material " << track.GetMaterial()->GetName() <<G4endl;
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G4cout << "MeanFreePath = " << currentInteractionLength/cm << "[cm]" <<G4endl;
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}
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#endif
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G4double value;
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if (currentInteractionLength <DBL_MAX) {
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value = theNumberOfInteractionLengthLeft * currentInteractionLength;
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} else {
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value = DBL_MAX;
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}
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return value;
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} else {
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//pre-assigned Decay time case
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// reminder proper time
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fRemainderLifeTime = pTime - track.GetProperTime();
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if (fRemainderLifeTime <= 0.0) fRemainderLifeTime = DBL_MIN;
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// use pre-assigned Decay time to determine PIL
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return (fRemainderLifeTime/aLife)*GetMeanFreePath(track, previousStepSize, condition);
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}
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}
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G4double G4Decay::AtRestGetPhysicalInteractionLength(
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const G4Track& track,
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G4ForceCondition* condition
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)
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{
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// condition is set to "Not Forced"
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*condition = NotForced;
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G4double pTime = track.GetDynamicParticle()->GetPreAssignedDecayProperTime();
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if (pTime >= 0.) {
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fRemainderLifeTime = pTime - track.GetProperTime();
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if (fRemainderLifeTime <= 0.0) fRemainderLifeTime = DBL_MIN;
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} else {
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fRemainderLifeTime =
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theNumberOfInteractionLengthLeft * GetMeanLifeTime(track, condition);
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}
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return fRemainderLifeTime;
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}
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