Magnetic resonance apparatus comprising a superconducting magnet.

摘要

The apparatus comprises a magnet system which is rotationally symmetrically arranged about a central axis (9) and which comprises a superconducting inner coil system (1) for generating a steady magnetic field in a measurement space (5) within the magnet system, and also comprises an outer coil system (7) which is arranged so as to be coaxial with the inner coil system and which is electrically connected in series therewith in order to shield the environment from the magnetic field generated by the inner coil system. The magnet system can be bridged by means of a superconducting persistent current switch (33) and comprises a superconducting shunt (37) which bridges a part of the magnet system which is situated between first and second connection points (39, 41). In order to improve the shielding of the measurement space (5) from the effects of external magnetic fields, at least one turn of a coil (17) forming part of the magnet system is situated between at least one of the connection points (39, 41) and the nearest end of the inner coil system (1). The shielding effect can be further enhanced by utilizing more than one shunt (37, 53). <IMAGE>