| 摘要 |
PROBLEM TO BE SOLVED: To suppress generation of eddy current caused by magnetic flux leakage by making winding position for winding a conductor to a structure which is based on required electric current steps successively from a position on the end part side of a coil segment in the axial direction of a bobbin. SOLUTION: Winding position of a coil segment is calculated by obtaining an ideal streamline function from an ideal electric current density function of coil segments 12Z-3 and -4 of a sealed coil for satisfying inclined magnetic field characteristics in the Z-axis direction determined analytically. As end part positions Z1 and Z1 on a bobbin are designated on both end parts and one turn is respectively wound, the streamline function is raised up by an electric current step value I. In similar way, the winding positions -Z2, -Z3 and -Z4 and Z2, Z3 and Z4 are determined by designating successively positions where electric current values in the vertical axis are 3I/2, 5I/2 and 7I./2. Leakage of magnetic field from both end parts in the bobbin axis direction of the coil segments 12 Z-3 and -4 of the sealed coil is decreased thereby and deterioration of quality of an MR image is also decreased. |
