include/Geant4/G4Mag_SpinEqRhs.hh

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0025 //
0026 // G4Mag_SpinEqRhs
0027 //
0028 // Class description:
0029 //
0030 // This is the equation of motion for a particle with spin in a pure
0031 // magnetic field. The three components of the particle's spin are
0032 // treated utilising BMT equation.
0033
0034 // Authors: John Apostolakis (CERN) & Peter Gumplinger (TRIUMF), 08.02.1999
0035 // --------------------------------------------------------------------
0036 #ifndef G4MAG_SPIN_EQRHS_HH
0037 #define G4MAG_SPIN_EQRHS_HH
0038
0039 #include "G4Types.hh"
0040 #include "G4Mag_EqRhs.hh"
0041 #include "G4ChargeState.hh"
0042
0043 class G4MagneticField;
0044
0045 /**
0046  * @brief G4Mag_SpinEqRhs defines the equation of motion for a particle with
0047  * spin in a pure magnetic field. The three components of the particle's spin
0048  * are treated utilising BMT equation.
0049  */
0050
0051 class G4Mag_SpinEqRhs : public G4Mag_EqRhs
0052 {
0053   public:
0054
0055     /**
0056      * Constructor for G4Mag_SpinEqRhs.
0057      *  @param[in] MagField Pointer to the associated magnetic field.
0058      */
0059     G4Mag_SpinEqRhs( G4MagneticField* MagField );
0060
0061     /**
0062      * Default Destructor.
0063      */
0064     ~G4Mag_SpinEqRhs() override = default;
0065
0066     /**
0067      * Sets the charge momentum mass value.
0068      */
0069     void SetChargeMomentumMass(G4ChargeState particleCharge,
0070                                G4double MomentumXc,
0071                                G4double mass) override;
0072
0073     /**
0074      * Calculates the value of the derivative, given the value of the field.
0075      *  @param[in] y Coefficients array.
0076      *  @param[in] B Field value.
0077      *  @param[out] dydx Derivatives array.
0078      */
0079     void EvaluateRhsGivenB( const G4double y[],
0080                             const G4double B[3],
0081                                   G4double dydx[] ) const override;
0082
0083     /**
0084      * Setter and getter for the magnetic anomaly.
0085      */
0086     inline void SetAnomaly(G4double a) { anomaly = a; }
0087     inline G4double GetAnomaly() const { return anomaly; }
0088
0089     /**
0090      * Returns the equation of motion type ID, i.e. "kEqMagneticWithSpin".
0091      */
0092     inline G4EquationType GetEquationType() const override { return kEqMagneticWithSpin; }
0093
0094   private:
0095
0096     G4double charge=0.0, mass=0.0, magMoment=0.0, spin=0.0;
0097     G4double omegac=0.0, anomaly=0.0011659208;
0098     G4double beta=0.0, gamma=0.0;
0099 };
0100
0101 #endif