| Geant4 Cross Reference |
1 //
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25 //
26 // G4Mag_EqRhs
27 //
28 // Class description:
29 //
30 // The "standard" equation of motion of a particle in a pure magnetic field.
31 // Other that might be required are:
32 // i) is when using a moving reference frame ... or
33 // ii) extending for other forces, e.g. an electric field
34
35 // Created: J.Apostolakis, CERN - 13.01.1997
36 // --------------------------------------------------------------------
37 #ifndef G4MAG_EQRHS_HH
38 #define G4MAG_EQRHS_HH
39
40 #include "G4Types.hh"
41 #include "G4ChargeState.hh"
42 #include "G4EquationOfMotion.hh"
43
44 class G4MagneticField;
45
46 class G4Mag_EqRhs : public G4EquationOfMotion
47 {
48 public:
49
50 G4Mag_EqRhs(G4MagneticField* magField);
51 ~G4Mag_EqRhs() override;
52 // Constructor and destructor. No actions.
53
54 void EvaluateRhsGivenB( const G4double y[],
55 const G4double B[3],
56 G4double dydx[] ) const override = 0;
57 // Given the value of the field "B", this function
58 // calculates the value of the derivative dydx.
59 // This is the _only_ function a subclass must define.
60 // The other two functions use Rhs_givenB.
61
62 inline G4double FCof() const { return fCof_val; }
63
64 void SetChargeMomentumMass( G4ChargeState particleCharge,
65 G4double MomentumXc,
66 G4double mass ) override;
67 private:
68
69 G4double fCof_val = 0.0;
70
71 static const G4double fUnitConstant; // Set to 0.299792458
72 // Coefficient in the Lorentz motion equation (Lorentz force), if the
73 // magnetic field B is in Tesla, the particle charge in units of the
74 // elementary (positron?) charge, the momentum P in MeV/c, and the
75 // space coordinates and path along the trajectory in mm.
76 };
77
78 #endif
79