摘要 |
PROBLEM TO BE SOLVED: To put an active shield type ellipsoidal gradient coil to practical use by definitely presenting the design method of the coil. SOLUTION: This gradient coil is provided with a main coil 21 constituted by winding a coil wire C1 around an ellipsoidal bobbin B1 and a shielded coil 22 constituted by winding another coil wire C2 around a bobbin B2 arranged coaxially with the bobbin B1 outside the main coil 21. The second bobbin B2 is formed in, for example, an ellipsoidal form having a larger diameter than the bobbin B1 has. The winding positions of the coil wires C1 and C2 of the coils 21 and 22 are decided so that the magnetic field generated from the main coil 21 may become about zero at a desired position outside the coil 21. At this time, the winding position of the coil wire C2 of the shielded coil 22 is decided so that the magnetic filed may become about zero at a desired position outside the main coil 21 when, for example, the winding position of the coil wire C1 of the main coil 21 is given.
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