MAGNET DEVICE AND MAGNETIC RESONANCE IMAGING APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To reduce asymmetry of eddy current caused by a connecting section in a superconductive magnet device in which upper and lower vacuum tubes are connected by a connecting tube. SOLUTION: The upper and lower vacuum tubes 9 and the connecting tube 24 connecting the vacuum tubes are made of materials with high electric resistance. A magnetic flux generated by a gradient magnet field coil is allowed to reach a pair of upper and lower secondary thermal shields 8 and a connective tube 23 that connects the upper and lower secondary thermal shields 8. A vertical slit 41 is located at the connective tube 23 connecting the upper and lower secondary thermal shields 8 so as to prevent the eddy current from flowing. As a result, the asymmetry of the eddy current occurring at the section of the connective tube 23 is reduced.