MAGNETIC RESONANCE DEVICE

摘要

PURPOSE: To suppress fluctuation of field in a magnet due to fluctuation of external field to such an extent as causing no damage on the image processing by arranging a superconducting shield coil system of different diameter coaxially with a superconducting static field magnet system for generating a field in a measuring space. CONSTITUTION: A shield coil system 22 having a controller 25 is arranged concentrically to a current coil system 1 for generating a strong, stabilized uniform field in a measuring space 3 on the outer circumference or on the inside thereof. The shield coil system comprises inner and outer pairs 241, 243 applied to the spool for the first magnet coil system 26 of a main magnet 1 and a central pair 242 applied to the spool for the second magnet coil system 28 of the main magnet 1 when viewed in the axial direction of the coil part 24 of three pairs. Uniformity of shield and field is optimized by the axial length of the inner pair 241 and the winding structure. Since the intensity of current passing through the shield coil system is low, a unit current conductor comprising a superconducting core wire and a non-superconducting sheath can be used.