G4Mag_EqRhs.hh

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//
// G4Mag_EqRhs
//
// Class description:
//
// The "standard" equation of motion of a particle in a pure magnetic field.
// Other that might be required are:
//     i) is when using a moving reference frame ... or
//    ii) extending for other forces, e.g. an electric field
 
// Created: J.Apostolakis, CERN - 13.01.1997
// --------------------------------------------------------------------
#ifndef G4MAG_EQRHS_HH
#define G4MAG_EQRHS_HH
 
#include "G4Types.hh"
#include "G4ChargeState.hh"
#include "G4EquationOfMotion.hh"
 
class G4MagneticField;
 
class G4Mag_EqRhs : public G4EquationOfMotion
{
  public:
 
    G4Mag_EqRhs(G4MagneticField* magField);
   ~G4Mag_EqRhs() override;
      // Constructor and destructor. No actions.
 
    void EvaluateRhsGivenB( const G4double y[],
                            const G4double B[3],
                                  G4double dydx[] ) const override = 0;
      // Given the value of the  field "B", this function 
      // calculates the value of the derivative dydx.
      // This is the _only_ function a subclass must define.
      // The other two functions use Rhs_givenB.
 
    inline G4double FCof() const { return fCof_val; }
 
    void SetChargeMomentumMass( G4ChargeState particleCharge,
                                G4double MomentumXc,
                                G4double mass ) override;
  private:
 
    G4double fCof_val = 0.0;
 
    static const G4double fUnitConstant;     // Set to 0.299792458
      // Coefficient in the Lorentz motion equation (Lorentz force), if the
      // magnetic field B is in Tesla, the particle charge in units of the 
      // elementary (positron?) charge, the momentum P in MeV/c, and the
      // space coordinates and path along the trajectory in mm.
};
 
#endif