Cryostat arrangements and mounting arrangements for cryostats

A cryocooler mounting method for mounting a coldhead of a cryocooler in a cryostat for allowing the extraction of heat from an interior of the cryostat by the cryocooler, the method comprising the steps of:

• providing a coldhead interface portion on the cold head;
• providing a sock portion in the cryostat, wherein said sock portion is arranged for receiving the coldhead, the sock portion comprising a receiving interface portion for receiving the coldhead interface portion so as to provide thermal contact between the receiving interface portion and the coldhead interface portion and to provide thermal contact between the cold head and the interior of the cryostat;
• wherein the coldhead interface portion comprises a plurality of flexible finger portions and the receiving interface portion comprises a bearing surface against which the finger portions are arranged to rest, wherein the receiving interface portion further includes an annular recess into which the plurality of flexible finger portions of the coldhead interface extend;
• and the method comprises the further steps of locating the finger portions on the bearing surface;
• and
• releasably clamping the finger portions against the bearing surface using a clamping ring to ensure thermal contact between the coldhead interface and the receiving interface.

A cryostat arrangement comprising a cryostat and a two-stage cryocooler having a coldhead for mounting in the cryostat for allowing the extraction of heat from an interior of the cryostat by the cryocooler, the cryostat arrangement comprising two coldhead interface portions provided on the coldhead and a sock portion mounted in the cryostat and arranged for receiving the coldhead, the sock portion comprising two receiving interface portions, a first of the two receiving interface portions for receiving a first of the two coldhead interface portions and a second of the two receiving interface portions for receiving a second of the two coldhead interface portions so as to provide thermal contact between the two receiving interface portions and the two coldhead interface portions and hence to provide thermal contact between the coldhead and the interior of the cryostat, wherein each of the two coldhead interface portions comprises a plurality of flexible finger portions and each of the two receiving interface portions comprises a bearing surface against which the respective finger portions of the two coldhead interface portions are arranged to rest, wherein each of the two receiving interface portions includes an annular recess into which the respective plurality of flexible finger portions of the respective coldhead interface extend;

• and the cryostat arrangement further comprising two clamping rings, a first of the two clamping rings for releasably clamping the plurality of finger portions of the first of the two coldhead interface portions against the bearing surface of the first of the two receiving interface portions to ensure thermal contact between the first coldhead interface portion and the first receiving interface portion, and a second of the two clamping rings for releasably clamping the plurality of finger portions of the second of the two coldhead interface portions against the bearing surface of the second of the two receiving interface portions to ensure thermal contact between the second coldhead interface portion and the second receiving interface portion.