| 摘要 |
<p>A super-conducting electro-magnet for use in an MRI system comprising a helium vessel (6) within which magnet windings (5) are positioned, a vacuum chamber (9) within which the helium vessel is contained, at least one thermal shield (11,12) positioned between the helium vessel and the vacuum chamber, a service turret (15) having a neck tube (16) which is arranged to extend through the thermal shield within the vacuum chamber so as to communicate with the helium vessel for filling purposes, the thermal shield being thermally coupled to the service turret neck tube by means of a plurality of flexible connector strips (26,27) fabricated from laminated conductive material which at one end are secured to the thermal shield and which at the other end thereof are secured to the service turret neck tube, sufficient strips being provided substantially to surround the service turret neck tube thereby to provide a substantially continuous thermally conductive junction between the service turret neck tube and the thermal shield. <IMAGE></p> |
