| 摘要 |
Device for generating an orientable and locally uniform magnetic field, including N≧3 identical assemblies of cylindrical coils, each assemblies having a first and a second coil, the coils being coaxial with an axis oriented along a direction z and arranged symmetrically on either side of the plane, with a gap in the axial direction, the assemblies arranged such that their outlines in a plane xy perpendicular to the z-axis are regularly spaced along a circle of center O and of radius a0>0, so to leave a central free space. A supply system supplies the coils with a current set to obtain, at the center of the device, a magnetic field having the desired orientation. The device may include two pairs of cylindrical coils having a common axis oriented in said z-direction and passing through the center of the circle, these coils being arranged symmetrically on either side of said xy-plane. |
| 主权项 |
1. Device for generating an orientable and locally uniform magnetic field, comprising N≧3 identical assemblies (EBn) of cylindrical coils, each of said assemblies comprising at least a first (Bn1) and a second (Bn2) coil, said coils being coaxial with an axis oriented along a direction z and being arranged symmetrically on either side of a plane xy perpendicular to said z-axis, with a gap in the axial direction, said assemblies being arranged such that their outlines in said xy-plane are regularly spaced along a circle of centre O and of radius a0>0, so as to leave a central free space (ELC), the device also comprising a supply system (SA) configured to supply each of said coils with a current Ini, n being an index representing the coil assembly and i being equal to 1 for said first coils and to 2 for said second coils, expressed by the sum of a first term Iz having a given value for all the coils, and a second term Ixy equal to (−1)i-1·I0·sin θ0·cos(φn−φ0), where I0 is a nominal current, φn is the azimuthal angle, relative to a reference direction in the xy-plane, of the nth coil assembly, φ0 is the azimuthal angle, relative to the same reference direction, of a magnetic field to be generated in the centre of said circle by said coils, and θ0 is the zenith angle of the same magnetic field relative to the z-axis, at least the angle φ0 being adjustable by a user. |
