G4EqEMFieldWithEDM Class Reference

#include <G4EqEMFieldWithEDM.hh>

Inheritance diagram for G4EqEMFieldWithEDM:

Collaboration diagram for G4EqEMFieldWithEDM:

Public Member Functions
	G4EqEMFieldWithEDM (G4ElectroMagneticField *emField)
	~G4EqEMFieldWithEDM ()
void	SetChargeMomentumMass (G4ChargeState particleCharge, G4double MomentumXc, G4double mass)
void	EvaluateRhsGivenB (const G4double y[], const G4double Field[], G4double dydx[]) const
void	SetAnomaly (G4double a)
G4double	GetAnomaly () const
void	SetEta (G4double n)
G4double	GetEta () const
Public Member Functions inherited from G4EquationOfMotion
	G4EquationOfMotion (G4Field *Field)
virtual	~G4EquationOfMotion ()
virtual void	EvaluateRhsGivenB (const G4double y[], const G4double B[3], G4double dydx[]) const =0
void	RightHandSide (const G4double y[], G4double dydx[]) const
void	EvaluateRhsReturnB (const G4double y[], G4double dydx[], G4double Field[]) const
void	GetFieldValue (const G4double Point[4], G4double Field[]) const
const G4Field *	GetFieldObj () const
void	SetFieldObj (G4Field *pField)

Private Attributes
G4double	charge
G4double	mass
G4double	magMoment
G4double	spin
G4double	fElectroMagCof
G4double	fMassCof
G4double	omegac
G4double	anomaly
G4double	eta
G4double	beta
G4double	gamma

Detailed Description

Definition at line 50 of file G4EqEMFieldWithEDM.hh.

Constructor & Destructor Documentation

G4EqEMFieldWithEDM()

G4EqEMFieldWithEDM::G4EqEMFieldWithEDM

(

G4ElectroMagneticField *

emField

)

Definition at line 45 of file G4EqEMFieldWithEDM.cc.

  : G4EquationOfMotion( emField ), charge(0.), mass(0.), magMoment(0.),
    spin(0.), fElectroMagCof(0.), fMassCof(0.), omegac(0.),
    anomaly(0.0011659208), eta(0.), beta(0.), gamma(0.)
{
}

~G4EqEMFieldWithEDM()

G4EqEMFieldWithEDM::~G4EqEMFieldWithEDM

(

)

Definition at line 52 of file G4EqEMFieldWithEDM.cc.

{
} 

Member Function Documentation

EvaluateRhsGivenB()

void G4EqEMFieldWithEDM::EvaluateRhsGivenB	(	const G4double	y[],
		const G4double	Field[],
		G4double	dydx[]
	)		const

Definition at line 85 of file G4EqEMFieldWithEDM.cc.

{

   // Components of y:
   //    0-2 dr/ds,
   //    3-5 dp/ds - momentum derivatives
   //    9-11 dSpin/ds = (1/beta) dSpin/dt - spin derivatives

   // The BMT equation, following J.D.Jackson, Classical
   // Electrodynamics, Second Edition, with additions for EDM
   // evolution from 
   // M.Nowakowski, et.al. Eur.J.Phys.26, pp 545-560, (2005)
   // or
   // Silenko, Phys.Rev.ST Accel.Beams 9:034003, (2006)

   // dS/dt = (e/m) S \cross 
   // MDM:         [ (g/2-1 +1/\gamma) B
   //               -(g/2-1)\gamma/(\gamma+1) (\beta \cdot B)\beta 
   //               -(g/2-\gamma/(\gamma+1) \beta \cross E 
   //
   // EDM:        eta/2( E - gamma/(gamma+1) \beta (\beta \cdot E)
   //                    + \beta \cross B ) ]
   //
   // where
   // S = \vec{s}, where S^2 = 1
   // B = \vec{B}
   // \beta = \vec{\beta} = \beta \vec{u} with u^2 = 1
   // E = \vec{E}

   G4double pSquared = y[3]*y[3] + y[4]*y[4] + y[5]*y[5] ;

   G4double Energy   = std::sqrt( pSquared + fMassCof );
   G4double cof2     = Energy/c_light ;

   G4double pModuleInverse  = 1.0/std::sqrt(pSquared) ;

   G4double inverse_velocity = Energy * pModuleInverse / c_light;

   G4double cof1     = fElectroMagCof*pModuleInverse ;

   dydx[0] = y[3]*pModuleInverse ;                         
   dydx[1] = y[4]*pModuleInverse ;                         
   dydx[2] = y[5]*pModuleInverse ;                        

   dydx[3] = cof1*(cof2*Field[3] + (y[4]*Field[2] - y[5]*Field[1])) ;
   
   dydx[4] = cof1*(cof2*Field[4] + (y[5]*Field[0] - y[3]*Field[2])) ; 
 
   dydx[5] = cof1*(cof2*Field[5] + (y[3]*Field[1] - y[4]*Field[0])) ;  
   
   dydx[6] = dydx[8] = 0.;//not used

   // Lab Time of flight
   dydx[7] = inverse_velocity;
   
   G4ThreeVector BField(Field[0],Field[1],Field[2]);
   G4ThreeVector EField(Field[3],Field[4],Field[5]);

   EField /= c_light;

   G4ThreeVector u(y[3], y[4], y[5]);
   u *= pModuleInverse;

   G4double udb = anomaly*beta*gamma/(1.+gamma) * (BField * u);
   G4double ucb = (anomaly+1./gamma)/beta;
   G4double uce = anomaly + 1./(gamma+1.);
   G4double ude = beta*gamma/(1.+gamma)*(EField*u);

   G4ThreeVector Spin(y[9],y[10],y[11]);

   G4double pcharge;
   if (charge == 0.) pcharge = 1.;
   else pcharge = charge;

   G4ThreeVector dSpin(0.,0.,0.);
   if (Spin.mag2() != 0.) {
      dSpin =
         pcharge*omegac*( ucb*(Spin.cross(BField))-udb*(Spin.cross(u))
                                 // from Jackson
                                 // -uce*Spin.cross(u.cross(EField)) )
                                 // but this form has one less operation
                         - uce*(u*(Spin*EField) - EField*(Spin*u))
                         + eta/2.*(Spin.cross(EField) - ude*(Spin.cross(u))
                                 // +Spin.cross(u.cross(Bfield))
                         + (u*(Spin*BField) - BField*(Spin*u)) ) );
   }
      
   dydx[ 9] = dSpin.x();
   dydx[10] = dSpin.y();
   dydx[11] = dSpin.z();

   return ;
}

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GetAnomaly()

G4double G4EqEMFieldWithEDM::GetAnomaly ( ) const

inline

Definition at line 69 of file G4EqEMFieldWithEDM.hh.

{ return anomaly; }

GetEta()

G4double G4EqEMFieldWithEDM::GetEta ( ) const

inline

Definition at line 73 of file G4EqEMFieldWithEDM.hh.

{ return eta; }

SetAnomaly()

void G4EqEMFieldWithEDM::SetAnomaly ( G4double  a )

inline

Definition at line 68 of file G4EqEMFieldWithEDM.hh.

{ anomaly = a; }

SetChargeMomentumMass()

void G4EqEMFieldWithEDM::SetChargeMomentumMass ( G4ChargeState  particleCharge, G4double  MomentumXc, G4double  mass  )

virtual

Implements G4EquationOfMotion.

Definition at line 57 of file G4EqEMFieldWithEDM.cc.

{
   charge   = particleCharge.GetCharge();
   mass      = particleMass;
   magMoment = particleCharge.GetMagneticDipoleMoment();
   spin      = particleCharge.GetSpin();

   fElectroMagCof =  eplus*charge*c_light;
   fMassCof = mass*mass;

   omegac = (eplus/mass)*c_light;

   G4double muB = 0.5*eplus*hbar_Planck/(mass/c_squared);

   G4double g_BMT;
   if ( spin != 0. ) g_BMT = (std::abs(magMoment)/muB)/spin;
   else g_BMT = 2.;

   anomaly = (g_BMT - 2.)/2.;

   G4double E = std::sqrt(sqr(MomentumXc)+sqr(mass));
   beta  = MomentumXc/E;
   gamma = E/mass;
}

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SetEta()

void G4EqEMFieldWithEDM::SetEta ( G4double  n )

inline

Definition at line 72 of file G4EqEMFieldWithEDM.hh.

{ eta = n; }

Member Data Documentation

anomaly

G4double G4EqEMFieldWithEDM::anomaly

private

Definition at line 83 of file G4EqEMFieldWithEDM.hh.

beta

G4double G4EqEMFieldWithEDM::beta

private

Definition at line 84 of file G4EqEMFieldWithEDM.hh.

charge

G4double G4EqEMFieldWithEDM::charge

private

Definition at line 78 of file G4EqEMFieldWithEDM.hh.

eta

G4double G4EqEMFieldWithEDM::eta

private

Definition at line 83 of file G4EqEMFieldWithEDM.hh.

fElectroMagCof

G4double G4EqEMFieldWithEDM::fElectroMagCof

private

Definition at line 80 of file G4EqEMFieldWithEDM.hh.

fMassCof

G4double G4EqEMFieldWithEDM::fMassCof

private

Definition at line 81 of file G4EqEMFieldWithEDM.hh.

gamma

G4double G4EqEMFieldWithEDM::gamma

private

Definition at line 84 of file G4EqEMFieldWithEDM.hh.

magMoment

G4double G4EqEMFieldWithEDM::magMoment

private

Definition at line 78 of file G4EqEMFieldWithEDM.hh.

mass

G4double G4EqEMFieldWithEDM::mass

private

Definition at line 78 of file G4EqEMFieldWithEDM.hh.

omegac

G4double G4EqEMFieldWithEDM::omegac

private

Definition at line 83 of file G4EqEMFieldWithEDM.hh.

spin

G4double G4EqEMFieldWithEDM::spin

private

Definition at line 78 of file G4EqEMFieldWithEDM.hh.

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

• G4EqEMFieldWithEDM.hh
• G4EqEMFieldWithEDM.cc