| 摘要 |
<p>A current lead assembly 10, a method of forming such an assembly or a magnetic resonance imaging system comprises: a superconducting magnet 14 within a vacuum chamber 12, where the magnet 14 is connected by a lead 34 to a contact 32 which is supported by a thermal isolation structure 38 secured to an inside wall of the vacuum chamber 12 and where a retractable lead 18 and contact 17 are linked to the chamber 12 and an actuator mechanism 26 to allow a connection to be made or broken between the said contact members 17, 32 within the thermal isolation structure 38 such that the contacts 17, 32 are at an ambient temperature whilst they are in contact with one another. The contacts may be arranged to be in a connected state during a current ramping operation and a disconnected state on the completion of this ramping operation. A flexible copper cable thermal connector 38 and the contacts 17, 32 may include thermally conductive copper material. The thermal isolating support structure 38 may be made of fibreglass. The lead assembly may minimize the heat load to the magnet from the high current (500 1000 Amps) carrying contacts 17, 32.</p> |
