include/Geant4/G4Mag_EqRhs.hh

0001 //
0002 // ********************************************************************
0003 // * License and Disclaimer                                           *
0004 // *                                                                  *
0005 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
0006 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
0007 // * conditions of the Geant4 Software License,  included in the file *
0008 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
0009 // * include a list of copyright holders.                             *
0010 // *                                                                  *
0011 // * Neither the authors of this software system, nor their employing *
0012 // * institutes,nor the agencies providing financial support for this *
0013 // * work  make  any representation or  warranty, express or implied, *
0014 // * regarding  this  software system or assume any liability for its *
0015 // * use.  Please see the license in the file  LICENSE  and URL above *
0016 // * for the full disclaimer and the limitation of liability.         *
0017 // *                                                                  *
0018 // * This  code  implementation is the result of  the  scientific and *
0019 // * technical work of the GEANT4 collaboration.                      *
0020 // * By using,  copying,  modifying or  distributing the software (or *
0021 // * any work based  on the software)  you  agree  to acknowledge its *
0022 // * use  in  resulting  scientific  publications,  and indicate your *
0023 // * acceptance of all terms of the Geant4 Software license.          *
0024 // ********************************************************************
0025 //
0026 // G4Mag_EqRhs
0027 //
0028 // Class description:
0029 //
0030 // The "standard" equation of motion of a particle in a pure magnetic field.
0031 // Other that might be required are:
0032 //     i) is when using a moving reference frame ... or
0033 //    ii) extending for other forces, e.g. an electric field
0034
0035 // Created: J.Apostolakis, CERN - 13.01.1997
0036 // --------------------------------------------------------------------
0037 #ifndef G4MAG_EQRHS_HH
0038 #define G4MAG_EQRHS_HH
0039
0040 #include "G4Types.hh"
0041 #include "G4ChargeState.hh"
0042 #include "G4EquationOfMotion.hh"
0043
0044 class G4MagneticField;
0045
0046 class G4Mag_EqRhs : public G4EquationOfMotion
0047 {
0048   public:
0049
0050     G4Mag_EqRhs(G4MagneticField* magField);
0051    ~G4Mag_EqRhs() override;
0052       // Constructor and destructor. No actions.
0053
0054     void EvaluateRhsGivenB( const G4double y[],
0055                             const G4double B[3],
0056                                   G4double dydx[] ) const override = 0;
0057       // Given the value of the  field "B", this function
0058       // calculates the value of the derivative dydx.
0059       // This is the _only_ function a subclass must define.
0060       // The other two functions use Rhs_givenB.
0061
0062     inline G4double FCof() const { return fCof_val; }
0063
0064     void SetChargeMomentumMass( G4ChargeState particleCharge,
0065                                 G4double MomentumXc,
0066                                 G4double mass ) override;
0067   private:
0068
0069     G4double fCof_val = 0.0;
0070
0071     static const G4double fUnitConstant;     // Set to 0.299792458
0072       // Coefficient in the Lorentz motion equation (Lorentz force), if the
0073       // magnetic field B is in Tesla, the particle charge in units of the
0074       // elementary (positron?) charge, the momentum P in MeV/c, and the
0075       // space coordinates and path along the trajectory in mm.
0076 };
0077
0078 #endif