VIBRATIONALLY ISOLATED CRYOGENIC DEVICE

摘要

A cryogenic cold head in a canister is partially surrounded by an isolation mass. An open portion of the mass permits access for connection of a vapor compression refrigeration unit to the cold head, which is highly conductive. Straps of braided copper suspend the isolation mass from the cold head. The isolation mass and straps have a fundamental frequency that is below the first harmonic frequency at the cold head as caused by the refrigeration unit. A temperature differential between the cold head and a device-mounting interface on the isolation mass is preferably less than 2.5K per watt of heat transferred. The device to be cooled is mounted directly to the isolation mass when the mass of the device is insignificant relative to the isolation mass. For further vibration isolation, the device is separated from the isolation mass by another braided strap. By mounting the isolation mass using a plurality of generally opposed braided straps, any orientation of the cold head/isolation mass combination may be used without jeopardizing performance.