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// $Id: G4QuadrupoleMagField.hh,v 1.4 2006/06/29 18:23:16 gunter Exp $
// GEANT4 tag $Name: geant4-09-02-cand-01 $
//
//
// class G4QuadrupoleMagField
//
// Class description:
//
// Class for creation of quadrupole magnetic field
//   fGradient - is the gradient value for quadrupole magnetic lense.
// Then the magnetic field components are:
//   Bx = B[0] = fGradient*X ,
//   By = B[1] = fGradient*Y ,
//   Bz = B[2] = 0 .
// Here X,Y,Z are the coordinates of a space point of interest.

// History:
// 3.2.97 - V.Grichine, created.
// -------------------------------------------------------------------

#ifndef G4QUADRUPOLEMAGFIELD_HH
#define G4QUADRUPOLEMAGFIELD_HH

#include "G4MagneticField.hh"

class G4QuadrupoleMagField : public G4MagneticField
{
  public: // with description

    G4QuadrupoleMagField(G4double pGradient);
   ~G4QuadrupoleMagField();

    void GetFieldValue(const G4double yTrack[],
                             G4double B[]     ) const;
  private:

    G4double fGradient;
};

#endif
