#include <G4SynchrotronRadiationInMat.hh>

Inheritance diagram for G4SynchrotronRadiationInMat:

Public Member Functions
	G4SynchrotronRadiationInMat (const G4String &processName="SynchrotronRadiation", G4ProcessType type=fElectromagnetic)

virtual	~G4SynchrotronRadiationInMat ()

G4double	GetMeanFreePath (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)

G4VParticleChange *	PostStepDoIt (const G4Track &track, const G4Step &Step)

G4double	GetPhotonEnergy (const G4Track &trackData, const G4Step &stepData)

G4double	GetRandomEnergySR (G4double, G4double)

G4double	GetProbSpectrumSRforInt (G4double)

G4double	GetIntProbSR (G4double)

G4double	GetProbSpectrumSRforEnergy (G4double)

G4double	GetEnergyProbSR (G4double)

G4double	GetIntegrandForAngleK (G4double)

G4double	GetAngleK (G4double)

G4double	GetAngleNumberAtGammaKsi (G4double)

G4bool	IsApplicable (const G4ParticleDefinition &)

void	SetRootNumber (G4int rn)

void	SetVerboseLevel (G4int v)

void	SetKsi (G4double ksi)

void	SetEta (G4double eta)

void	SetPsiGamma (G4double psg)

void	SetOrderAngleK (G4double ord)

Public Member Functions inherited from G4VDiscreteProcess
	G4VDiscreteProcess (const G4String &, G4ProcessType aType=fNotDefined)

	G4VDiscreteProcess (G4VDiscreteProcess &)

virtual	~G4VDiscreteProcess ()

virtual G4double	PostStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)

virtual G4double	AlongStepGetPhysicalInteractionLength (const G4Track &, G4double, G4double, G4double &, G4GPILSelection *)

virtual G4double	AtRestGetPhysicalInteractionLength (const G4Track &, G4ForceCondition *)

virtual G4VParticleChange *	AtRestDoIt (const G4Track &, const G4Step &)

virtual G4VParticleChange *	AlongStepDoIt (const G4Track &, const G4Step &)

Public Member Functions inherited from G4VProcess
	G4VProcess (const G4String &aName="NoName", G4ProcessType aType=fNotDefined)

	G4VProcess (const G4VProcess &right)

virtual	~G4VProcess ()

G4int	operator== (const G4VProcess &right) const

G4int	operator!= (const G4VProcess &right) const

G4double	GetCurrentInteractionLength () const

void	SetPILfactor (G4double value)

G4double	GetPILfactor () const

G4double	AlongStepGPIL (const G4Track &track, G4double previousStepSize, G4double currentMinimumStep, G4double &proposedSafety, G4GPILSelection *selection)

G4double	AtRestGPIL (const G4Track &track, G4ForceCondition *condition)

G4double	PostStepGPIL (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)

virtual void	BuildPhysicsTable (const G4ParticleDefinition &)

virtual void	PreparePhysicsTable (const G4ParticleDefinition &)

virtual G4bool	StorePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)

virtual G4bool	RetrievePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)

const G4String &	GetPhysicsTableFileName (const G4ParticleDefinition *, const G4String &directory, const G4String &tableName, G4bool ascii=false)

const G4String &	GetProcessName () const

G4ProcessType	GetProcessType () const

void	SetProcessType (G4ProcessType)

G4int	GetProcessSubType () const

void	SetProcessSubType (G4int)

virtual void	StartTracking (G4Track *)

virtual void	EndTracking ()

virtual void	SetProcessManager (const G4ProcessManager *)

virtual const G4ProcessManager *	GetProcessManager ()

virtual void	ResetNumberOfInteractionLengthLeft ()

G4double	GetNumberOfInteractionLengthLeft () const

G4double	GetTotalNumberOfInteractionLengthTraversed () const

G4bool	isAtRestDoItIsEnabled () const

G4bool	isAlongStepDoItIsEnabled () const

G4bool	isPostStepDoItIsEnabled () const

virtual void	DumpInfo () const

void	SetVerboseLevel (G4int value)

G4int	GetVerboseLevel () const

virtual void	SetMasterProcess (G4VProcess *masterP)

const G4VProcess *	GetMasterProcess () const

virtual void	BuildWorkerPhysicsTable (const G4ParticleDefinition &part)

virtual void	PrepareWorkerPhysicsTable (const G4ParticleDefinition &)

Static Public Member Functions
static G4double	GetLambdaConst ()

static G4double	GetEnergyConst ()

Static Public Member Functions inherited from G4VProcess
static const G4String &	GetProcessTypeName (G4ProcessType)

Additional Inherited Members
Protected Member Functions inherited from G4VProcess
void	SubtractNumberOfInteractionLengthLeft (G4double previousStepSize)

void	ClearNumberOfInteractionLengthLeft ()

Protected Attributes inherited from G4VProcess
const G4ProcessManager *	aProcessManager

G4VParticleChange *	pParticleChange

G4ParticleChange	aParticleChange

G4double	theNumberOfInteractionLengthLeft

G4double	currentInteractionLength

G4double	theInitialNumberOfInteractionLength

G4String	theProcessName

G4String	thePhysicsTableFileName

G4ProcessType	theProcessType

G4int	theProcessSubType

G4double	thePILfactor

G4bool	enableAtRestDoIt

G4bool	enableAlongStepDoIt

G4bool	enablePostStepDoIt

G4int	verboseLevel

Detailed Description

Definition at line 68 of file G4SynchrotronRadiationInMat.hh.

Constructor & Destructor Documentation

G4SynchrotronRadiationInMat::G4SynchrotronRadiationInMat	(	const G4String &	processName = `"SynchrotronRadiation"`,
		G4ProcessType	type = `fElectromagnetic`
	)

Definition at line 123 of file G4SynchrotronRadiationInMat.cc.

References fSynchrotronRadiation, G4TransportationManager::GetPropagatorInField(), G4TransportationManager::GetTransportationManager(), and G4VProcess::SetProcessSubType().

                      :G4VDiscreteProcess (processName, type),
   LowestKineticEnergy (10.*keV),
   HighestKineticEnergy (100.*TeV),
   TotBin(200),
   theGamma (G4Gamma::Gamma() ),
   theElectron ( G4Electron::Electron() ),
   thePositron ( G4Positron::Positron() ), 
   GammaCutInKineticEnergy(0),
   ElectronCutInKineticEnergy(0),
   PositronCutInKineticEnergy(0),
   ParticleCutInKineticEnergy(0),
   fAlpha(0.0), fRootNumber(80),
   fVerboseLevel( verboseLevel )
 {
   G4TransportationManager* transportMgr = G4TransportationManager::GetTransportationManager();
 
   fFieldPropagator = transportMgr->GetPropagatorInField();
   SetProcessSubType(fSynchrotronRadiation);
   CutInRange = GammaCutInKineticEnergyNow = ElectronCutInKineticEnergyNow = 
     PositronCutInKineticEnergyNow =  ParticleCutInKineticEnergyNow = fKsi = 
     fPsiGamma = fEta = fOrderAngleK = 0.0;
 }

G4SynchrotronRadiationInMat::~G4SynchrotronRadiationInMat ( )

virtual

Definition at line 152 of file G4SynchrotronRadiationInMat.cc.

153 {}

Member Function Documentation

G4double G4SynchrotronRadiationInMat::GetAngleK ( G4double eta )

Definition at line 636 of file G4SynchrotronRadiationInMat.cc.

References test::a, GetIntegrandForAngleK(), G4Integrator< T, F >::Laguerre(), and n.

Referenced by GetAngleNumberAtGammaKsi().

 {
   fEta = eta; // should be > 0. !
   G4int n;
   G4double result, a;
 
   a = fAlpha;        // always = 0.
   n = fRootNumber;   // around default = 80
 
   G4Integrator<G4SynchrotronRadiationInMat, G4double(G4SynchrotronRadiationInMat::*)(G4double)> integral;
 
   result = integral.Laguerre(this, 
            &G4SynchrotronRadiationInMat::GetIntegrandForAngleK, a, n);
 
   return result;
 }

G4double G4SynchrotronRadiationInMat::GetAngleNumberAtGammaKsi ( G4double gpsi )

Definition at line 657 of file G4SynchrotronRadiationInMat.cc.

References GetAngleK().

 {
   G4double result, funK, funK2, gpsi2 = gpsi*gpsi;
 
   fPsiGamma    = gpsi;
   fEta         = 0.5*fKsi*(1 + gpsi2)*std::sqrt(1 + gpsi2);
  
   fOrderAngleK = 1./3.;
   funK         = GetAngleK(fEta); 
   funK2        = funK*funK;
 
   result       = gpsi2*funK2/(1 + gpsi2);
 
   fOrderAngleK = 2./3.;
   funK         = GetAngleK(fEta); 
   funK2        = funK*funK;
 
   result      += funK2;
   result      *= (1 + gpsi2)*fKsi;
      
   return result;
 }

static G4double G4SynchrotronRadiationInMat::GetEnergyConst ( )

inlinestatic

Definition at line 110 of file G4SynchrotronRadiationInMat.hh.

110 { return fEnergyConst; };

G4double G4SynchrotronRadiationInMat::GetEnergyProbSR ( G4double ksi )

Definition at line 599 of file G4SynchrotronRadiationInMat.cc.

References test::a, GetProbSpectrumSRforEnergy(), G4Integrator< T, F >::Laguerre(), n, and python.hepunit::pi.

 {
   if (ksi <= 0.) return 1.0;
   fKsi = ksi; // should be > 0. !
   G4int n;
   G4double result, a;
 
   a = fAlpha;        // always = 0.
   n = fRootNumber;   // around default = 80
 
   G4Integrator<G4SynchrotronRadiationInMat, G4double(G4SynchrotronRadiationInMat::*)(G4double)> integral;
 
   result = integral.Laguerre(this, 
            &G4SynchrotronRadiationInMat::GetProbSpectrumSRforEnergy, a, n);
 
   result *= 9.*std::sqrt(3.)*ksi/8./pi;
 
   return result;
 }

G4double G4SynchrotronRadiationInMat::GetIntegrandForAngleK ( G4double t )

Definition at line 623 of file G4SynchrotronRadiationInMat.cc.

Referenced by GetAngleK().

 {
   G4double result, hypCos=std::cosh(t);
   
   result  = std::cosh(fOrderAngleK*t)*std::exp(t - fEta*hypCos); // fEta > 0. !
   result /= hypCos;
   return result;
 }

G4double G4SynchrotronRadiationInMat::GetIntProbSR ( G4double ksi )

Definition at line 560 of file G4SynchrotronRadiationInMat.cc.

References test::a, GetProbSpectrumSRforInt(), G4Integrator< T, F >::Laguerre(), n, and python.hepunit::pi.

 {
   if (ksi <= 0.) return 1.0;
   fKsi = ksi; // should be > 0. !
   G4int n;
   G4double result, a;
 
   a = fAlpha;        // always = 0.
   n = fRootNumber;   // around default = 80
 
   G4Integrator<G4SynchrotronRadiationInMat, G4double(G4SynchrotronRadiationInMat::*)(G4double)> integral;
 
   result = integral.Laguerre(this, 
            &G4SynchrotronRadiationInMat::GetProbSpectrumSRforInt, a, n);
 
   result *= 3./5./pi;
 
   return result;
 }

static G4double G4SynchrotronRadiationInMat::GetLambdaConst ( )

inlinestatic

Definition at line 109 of file G4SynchrotronRadiationInMat.hh.

109 { return fLambdaConst; };

G4double G4SynchrotronRadiationInMat::GetMeanFreePath	(	const G4Track &	track,
		G4double	previousStepSize,
		G4ForceCondition *	condition
	)

virtual

Implements G4VDiscreteProcess.

Definition at line 174 of file G4SynchrotronRadiationInMat.cc.

References CLHEP::Hep3Vector::cross(), DBL_MAX, G4PropagatorInField::FindAndSetFieldManager(), G4cout, G4endl, G4DynamicParticle::GetDefinition(), G4FieldManager::GetDetectorField(), G4Track::GetDynamicParticle(), G4Field::GetFieldValue(), G4Track::GetGlobalTime(), G4DynamicParticle::GetKineticEnergy(), G4DynamicParticle::GetMass(), G4DynamicParticle::GetMomentumDirection(), G4ParticleDefinition::GetPDGCharge(), G4Track::GetPosition(), G4DynamicParticle::GetTotalEnergy(), G4DynamicParticle::GetTotalMomentum(), G4Track::GetVolume(), python.hepunit::m, CLHEP::Hep3Vector::mag(), NotForced, CLHEP::Hep3Vector::x(), CLHEP::Hep3Vector::y(), and CLHEP::Hep3Vector::z().

 {
   // gives the MeanFreePath in GEANT4 internal units
   G4double MeanFreePath;
 
   const G4DynamicParticle* aDynamicParticle = trackData.GetDynamicParticle();
   // G4Material* aMaterial = trackData.GetMaterial();
 
   //G4bool isOutRange ;
  
   *condition = NotForced ;
 
   G4double gamma = aDynamicParticle->GetTotalEnergy()/
                    aDynamicParticle->GetMass();
 
   G4double particleCharge = aDynamicParticle->GetDefinition()->GetPDGCharge();
 
   G4double KineticEnergy = aDynamicParticle->GetKineticEnergy();
 
   if ( KineticEnergy <  LowestKineticEnergy || gamma < 1.0e3 )  MeanFreePath = DBL_MAX; 
   else
   {
 
     G4ThreeVector  FieldValue;
     const G4Field*   pField = 0;
 
     G4FieldManager* fieldMgr=0;
     G4bool          fieldExertsForce = false;
 
     if( (particleCharge != 0.0) )
     {
       fieldMgr = fFieldPropagator->FindAndSetFieldManager( trackData.GetVolume() );
 
       if ( fieldMgr != 0 ) 
       {
         // If the field manager has no field, there is no field !
 
         fieldExertsForce = ( fieldMgr->GetDetectorField() != 0 );
       }
     }
     if ( fieldExertsForce )
     {  
       pField = fieldMgr->GetDetectorField() ;
       G4ThreeVector  globPosition = trackData.GetPosition();
 
       G4double  globPosVec[4], FieldValueVec[6];
 
       globPosVec[0] = globPosition.x();
       globPosVec[1] = globPosition.y();
       globPosVec[2] = globPosition.z();
       globPosVec[3] = trackData.GetGlobalTime();
 
       pField->GetFieldValue( globPosVec, FieldValueVec );
 
       FieldValue = G4ThreeVector( FieldValueVec[0], 
                                    FieldValueVec[1], 
                                    FieldValueVec[2]   );
 
        
 
       G4ThreeVector unitMomentum = aDynamicParticle->GetMomentumDirection(); 
       G4ThreeVector unitMcrossB  = FieldValue.cross(unitMomentum) ;
       G4double perpB             = unitMcrossB.mag() ;
       G4double beta              = aDynamicParticle->GetTotalMomentum()/
                                    (aDynamicParticle->GetTotalEnergy()    );
 
       if( perpB > 0.0 ) MeanFreePath = fLambdaConst*beta/perpB;
       else              MeanFreePath = DBL_MAX;       
     }
     else  MeanFreePath = DBL_MAX;    
   }
   if(fVerboseLevel > 0)
   {
     G4cout<<"G4SynchrotronRadiationInMat::MeanFreePath = "<<MeanFreePath/m<<" m"<<G4endl;
   }
   return MeanFreePath; 
 } 

G4double G4SynchrotronRadiationInMat::GetPhotonEnergy	(	const G4Track &	trackData,
		const G4Step &	stepData
	)

Definition at line 421 of file G4SynchrotronRadiationInMat.cc.

References CLHEP::Hep3Vector::cross(), G4PropagatorInField::FindAndSetFieldManager(), G4UniformRand, G4DynamicParticle::GetDefinition(), G4FieldManager::GetDetectorField(), G4Track::GetDynamicParticle(), G4Field::GetFieldValue(), G4DynamicParticle::GetMass(), G4DynamicParticle::GetMomentumDirection(), G4ParticleDefinition::GetPDGCharge(), G4Track::GetPosition(), G4DynamicParticle::GetTotalEnergy(), G4Track::GetVolume(), CLHEP::Hep3Vector::mag(), CLHEP::Hep3Vector::x(), CLHEP::Hep3Vector::y(), and CLHEP::Hep3Vector::z().

 {
   G4int i ;
   G4double energyOfSR = -1.0 ;
   //G4Material* aMaterial=trackData.GetMaterial() ;
 
   const G4DynamicParticle* aDynamicParticle=trackData.GetDynamicParticle();
 
   G4double gamma = aDynamicParticle->GetTotalEnergy()/
                    (aDynamicParticle->GetMass()              ) ;
 
   G4double particleCharge = aDynamicParticle->GetDefinition()->GetPDGCharge();
 
   G4ThreeVector  FieldValue;
   const G4Field*   pField = 0 ;
 
   G4FieldManager* fieldMgr=0;
   G4bool          fieldExertsForce = false;
 
   if( (particleCharge != 0.0) )
   {
     fieldMgr = fFieldPropagator->FindAndSetFieldManager( trackData.GetVolume() );
     if ( fieldMgr != 0 ) 
     {
       // If the field manager has no field, there is no field !
 
       fieldExertsForce = ( fieldMgr->GetDetectorField() != 0 );
     }
   }
   if ( fieldExertsForce )
   {  
     pField = fieldMgr->GetDetectorField();
     G4ThreeVector  globPosition = trackData.GetPosition();
     G4double  globPosVec[3], FieldValueVec[3];
 
     globPosVec[0] = globPosition.x();
     globPosVec[1] = globPosition.y();
     globPosVec[2] = globPosition.z();
 
     pField->GetFieldValue( globPosVec, FieldValueVec );
     FieldValue = G4ThreeVector( FieldValueVec[0], 
                                    FieldValueVec[1], 
                                    FieldValueVec[2]   );
        
     G4ThreeVector unitMomentum = aDynamicParticle->GetMomentumDirection(); 
     G4ThreeVector unitMcrossB  = FieldValue.cross(unitMomentum) ;
     G4double perpB             = unitMcrossB.mag();
     if( perpB > 0.0 )
     {
       // M-C of synchrotron photon energy
 
       G4double random = G4UniformRand() ;
       for(i=0;i<200;i++)
       {
         if(random >= fIntegralProbabilityOfSR[i]) break ;
       }
       energyOfSR = 0.0001*i*i*fEnergyConst*gamma*gamma*perpB ;
 
       // check against insufficient energy
 
       if(energyOfSR <= 0.0)
       {
         return -1.0 ;
       }
       //G4double kineticEnergy = aDynamicParticle->GetKineticEnergy();
       //G4ParticleMomentum 
       //particleDirection = aDynamicParticle->GetMomentumDirection();
 
       // Gamma production cut in this material
       //G4double 
       //gammaEnergyCut = (G4Gamma::GetCutsInEnergy())[aMaterial->GetIndex()];
 
       // SR photon has energy more than the current material cut
       // M-C of its direction
       
       //G4double Teta = G4UniformRand()/gamma ;    // Very roughly
 
       //G4double Phi  = twopi * G4UniformRand() ;
     }       
     else
     {
       return -1.0 ;
     }
   }     
   return energyOfSR ;
 }

G4double G4SynchrotronRadiationInMat::GetProbSpectrumSRforEnergy ( G4double t )

Definition at line 584 of file G4SynchrotronRadiationInMat.cc.

Referenced by GetEnergyProbSR().

 {
   G4double result, hypCos=std::cosh(t);
   
   result = std::cosh(5.*t/3.)*std::exp(t - fKsi*hypCos); // fKsi > 0. !
   result /= hypCos;
   return result;
 }

G4double G4SynchrotronRadiationInMat::GetProbSpectrumSRforInt ( G4double t )

Definition at line 544 of file G4SynchrotronRadiationInMat.cc.

Referenced by GetIntProbSR().

 {
   G4double result, hypCos2, hypCos=std::cosh(t);
 
   hypCos2 = hypCos*hypCos;  
   result = std::cosh(5.*t/3.)*std::exp(t-fKsi*hypCos); // fKsi > 0. !
   result /= hypCos2;
   return result;
 }

G4double G4SynchrotronRadiationInMat::GetRandomEnergySR	(	G4double	gamma,
		G4double	perpB
	)

Definition at line 514 of file G4SynchrotronRadiationInMat.cc.

References G4UniformRand, and position.

Referenced by PostStepDoIt().

 {
   G4int i, iMax;
   G4double energySR, random, position;
 
   iMax = 200;
   random = G4UniformRand();
 
   for( i = 0; i < iMax; i++ )
   {
     if( random >= fIntegralProbabilityOfSR[i] ) break;
   }
   if(i <= 0 )        position = G4UniformRand(); // 0.
   else if( i>= iMax) position = G4double(iMax);
   else position = i + G4UniformRand(); // -1
   // 
   // it was in initial implementation:
   //       energyOfSR = 0.0001*i*i*fEnergyConst*gamma*gamma*perpB ;
 
   energySR = 0.0001*position*position*fEnergyConst*gamma*gamma*perpB;
 
   if( energySR  < 0. ) energySR = 0.;
 
   return energySR;
 }

G4bool G4SynchrotronRadiationInMat::IsApplicable ( const G4ParticleDefinition & particle )

virtual

Reimplemented from G4VProcess.

Definition at line 157 of file G4SynchrotronRadiationInMat.cc.

 {
 
   return ( ( &particle == (const G4ParticleDefinition *)theElectron ) ||
        ( &particle == (const G4ParticleDefinition *)thePositron )    );
 
 }

G4VParticleChange * G4SynchrotronRadiationInMat::PostStepDoIt	(	const G4Track &	track,
		const G4Step &	Step
	)

virtual

Reimplemented from G4VDiscreteProcess.

Definition at line 259 of file G4SynchrotronRadiationInMat.cc.

References G4ParticleChange::AddSecondary(), G4VProcess::aParticleChange, CLHEP::Hep3Vector::cross(), fcos(), G4PropagatorInField::FindAndSetFieldManager(), fStopAndKill, fStopButAlive, G4cout, G4endl, G4UniformRand, G4Gamma::Gamma(), G4DynamicParticle::GetDefinition(), G4FieldManager::GetDetectorField(), G4Track::GetDynamicParticle(), G4Field::GetFieldValue(), G4Track::GetGlobalTime(), G4DynamicParticle::GetKineticEnergy(), G4DynamicParticle::GetMass(), G4DynamicParticle::GetMomentumDirection(), G4ParticleDefinition::GetPDGCharge(), G4Track::GetPosition(), GetRandomEnergySR(), G4DynamicParticle::GetTotalEnergy(), G4Track::GetVolume(), G4ParticleChange::Initialize(), python.hepunit::keV, CLHEP::Hep3Vector::mag(), G4VDiscreteProcess::PostStepDoIt(), G4ParticleChange::ProposeEnergy(), G4VParticleChange::ProposeLocalEnergyDeposit(), G4ParticleChange::ProposeMomentumDirection(), G4VParticleChange::ProposeTrackStatus(), CLHEP::Hep3Vector::rotateUz(), G4VParticleChange::SetNumberOfSecondaries(), G4DynamicParticle::SetPolarization(), python.hepunit::twopi, CLHEP::Hep3Vector::unit(), CLHEP::Hep3Vector::x(), CLHEP::Hep3Vector::y(), and CLHEP::Hep3Vector::z().

 {
   aParticleChange.Initialize(trackData);
 
   const G4DynamicParticle* aDynamicParticle=trackData.GetDynamicParticle();
 
   G4double gamma = aDynamicParticle->GetTotalEnergy()/
                    (aDynamicParticle->GetMass()              );
 
   if(gamma <= 1.0e3 ) 
   {
     return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
   }
   G4double particleCharge = aDynamicParticle->GetDefinition()->GetPDGCharge();
 
   G4ThreeVector  FieldValue;
   const G4Field*   pField = 0 ;
 
   G4FieldManager* fieldMgr=0;
   G4bool          fieldExertsForce = false;
 
   if( (particleCharge != 0.0) )
   {
     fieldMgr = fFieldPropagator->FindAndSetFieldManager( trackData.GetVolume() );
     if ( fieldMgr != 0 ) 
     {
       // If the field manager has no field, there is no field !
 
       fieldExertsForce = ( fieldMgr->GetDetectorField() != 0 );
     }
   }
   if ( fieldExertsForce )
   {
     pField = fieldMgr->GetDetectorField() ;
     G4ThreeVector  globPosition = trackData.GetPosition() ;
     G4double  globPosVec[4], FieldValueVec[6] ;
     globPosVec[0] = globPosition.x() ;
     globPosVec[1] = globPosition.y() ;
     globPosVec[2] = globPosition.z() ;
     globPosVec[3] = trackData.GetGlobalTime();
 
     pField->GetFieldValue( globPosVec, FieldValueVec ) ;
     FieldValue = G4ThreeVector( FieldValueVec[0], 
                                    FieldValueVec[1], 
                                    FieldValueVec[2]   );
        
     G4ThreeVector unitMomentum = aDynamicParticle->GetMomentumDirection(); 
     G4ThreeVector unitMcrossB = FieldValue.cross(unitMomentum);
     G4double perpB = unitMcrossB.mag() ;
     if(perpB > 0.0)
     {
       // M-C of synchrotron photon energy
 
       G4double energyOfSR = GetRandomEnergySR(gamma,perpB);
 
       if(fVerboseLevel > 0)
       {
         G4cout<<"SR photon energy = "<<energyOfSR/keV<<" keV"<<G4endl;
       }
       // check against insufficient energy
 
       if( energyOfSR <= 0.0 )
       {
         return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
       }
       G4double kineticEnergy = aDynamicParticle->GetKineticEnergy();
       G4ParticleMomentum 
       particleDirection = aDynamicParticle->GetMomentumDirection();
 
       // M-C of its direction, simplified dipole busted approach
       
       // G4double Teta = G4UniformRand()/gamma ;    // Very roughly
 
       G4double cosTheta, sinTheta, fcos, beta;
 
   do
   { 
     cosTheta = 1. - 2.*G4UniformRand();
     fcos     = (1 + cosTheta*cosTheta)*0.5;
   }
   while( fcos < G4UniformRand() );
 
   beta = std::sqrt(1. - 1./(gamma*gamma));
 
   cosTheta = (cosTheta + beta)/(1. + beta*cosTheta);
 
   if( cosTheta >  1. ) cosTheta =  1.;
   if( cosTheta < -1. ) cosTheta = -1.;
 
   sinTheta = std::sqrt(1. - cosTheta*cosTheta );
 
       G4double Phi  = twopi * G4UniformRand() ;
 
       G4double dirx = sinTheta*std::cos(Phi) , 
                diry = sinTheta*std::sin(Phi) , 
                dirz = cosTheta;
 
       G4ThreeVector gammaDirection ( dirx, diry, dirz);
       gammaDirection.rotateUz(particleDirection);   
  
       // polarization of new gamma
 
       // G4double sx =  std::cos(Teta)*std::cos(Phi);
       // G4double sy =  std::cos(Teta)*std::sin(Phi);
       // G4double sz = -std::sin(Teta);
 
       G4ThreeVector gammaPolarization = FieldValue.cross(gammaDirection);
       gammaPolarization = gammaPolarization.unit();
 
       // (sx, sy, sz);
       // gammaPolarization.rotateUz(particleDirection);
 
       // create G4DynamicParticle object for the SR photon
  
       G4DynamicParticle* aGamma= new G4DynamicParticle ( G4Gamma::Gamma(),
                                                          gammaDirection, 
                                                          energyOfSR      );
       aGamma->SetPolarization( gammaPolarization.x(),
                                gammaPolarization.y(),
                                gammaPolarization.z() );
 
 
       aParticleChange.SetNumberOfSecondaries(1);
       aParticleChange.AddSecondary(aGamma); 
 
       // Update the incident particle 
    
       G4double newKinEnergy = kineticEnergy - energyOfSR ;
       
       if (newKinEnergy > 0.)
       {
         aParticleChange.ProposeMomentumDirection( particleDirection );
         aParticleChange.ProposeEnergy( newKinEnergy );
         aParticleChange.ProposeLocalEnergyDeposit (0.); 
       } 
       else
       { 
         aParticleChange.ProposeEnergy( 0. );
         aParticleChange.ProposeLocalEnergyDeposit (0.);
         G4double charge = aDynamicParticle->GetDefinition()->GetPDGCharge();   
         if (charge<0.)
         {
            aParticleChange.ProposeTrackStatus(fStopAndKill) ;
     }
         else      
         {
           aParticleChange.ProposeTrackStatus(fStopButAlive) ;
     }
       } 
     }       
     else
     {
       return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
     }
   }     
   return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
 }