MAGNET DEVICE AND MAGNETIC RESONANCE IMAGING APPARATUS COMPRISING IT

摘要

In a superconducting magnet device comprising upper and lower vacuum chamber coupled through a coupling pipe, the upper and lower chambers (9) and the coupling pipe (24) are made of a high electric resistance material, and the magnetic flux of a gradient magnetic field coil reaches a pair of upper and lower second heat shields (8) and a coupling pipe (23) coupling the upper and lower second heat shields (8). The coupling pipe (23) coupling the upper and lower second heat shields (8) is provided with a slit (cut) (41) extending in the vertical direction so that no eddy current flows, thus reducing asymmetry of eddy current generated in the coupling pipe (23). The artifact caused by asymmetric eddy current is thereby reduced in an MRI apparatus comprising such a magnet device.