Thermal contact between cryogenic refrigerators and cooled components

• US 10,408,384 B2
• Filed: 08/09/2018
• Issued: 09/10/2019
• Est. Priority Date: 04/17/2013
• Status: Active Grant

• Current Assignee: Siemens Healthcare Limited. (Siemens AG)
• Original Assignee: Siemens Healthcare Limited. (Siemens AG)
• Inventors: Simpkins, Michael
• Primary Examiner(s): Bauer, Cassey D
• Assistant Examiner(s): Hopkins, Jenna M
• Application Number:
  US16/059,172
• Publication Number:
  US 20180372393A1
• Time in Patent Office: 397 Days
• Field of Search: 62 511, 62 6
• CPC Class Codes: F17C 2227/0353 using cryocooler
• CPC Class Codes: F17C 3/085 Cryostats
• CPC Class Codes: F25B 9/14 characterised by the cycle used, e.g. Stirling cycle
• CPC Class Codes: F25D 19/006 Thermal coupling structure or interface
• CPC Class Codes: F28F 13/18 by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
• CPC Class Codes: G01R 33/3804 Additional hardware for cooling or heating of the magnet assembly, for housing a cooled or heated part of the magnet assembly or for temperature control of the magnet assembly
• CPC Class Codes: G01R 33/3815 with superconducting coils, e.g. power supply therefor
• CPC Class Codes: H01F 6/04 Cooling

Abstract

An arrangement for mounting a two stage cryogenic refrigerator into a cryostat has a vacuum sock accommodates at least a part of the refrigerator, attachment means and attaches an upper part of the refrigerator to a surface of the cryostat around an opening of the vacuum sock, a thermally conductive portion of a wall of the vacuum sock that, in use, is thermally and mechanically in contact with a second cooling stage of the refrigerator, and arrangements are provided that thermally connect a first stage of the refrigerator to a thermal radiation shield of the cryostat.

Claims

1. An arrangement for mounting a two stage cryogenic refrigerator into a cryostat, the arrangement comprising:

a vacuum sock for accommodating at least a part of the refrigerator;

attachment means for attaching an upper part of the refrigerator to a surface of the cryostat around an opening of the vacuum sock;

a thermally conductive portion of a wall of the vacuum sock which, in use, is thermally and mechanically in contact with a second cooling stage of the refrigerator;

arrangements are provided for thermally connecting a first stage of the refrigerator to a thermal radiation shield of the cryostat;

the said arrangements comprising a bellows structure within the vacuum sock, the bellows structure containing a sealed mass of cryogen gas, whereby said bellows structure is in a retracted position when the vacuum sock is at atmospheric pressure, and which is in an extended position when the vacuum sock is under vacuum, wherein, in its extended position, the bellows presses a thermally conductive contact piece into thermal and mechanical contact with a first cooling stage of the refrigerator; and

wherein the thermally conductive contact piece is arranged to rotate about an axle in response to the bellows structure being in a retracted position when the vacuum sock is at atmospheric pressure, and being in an extended position when the vacuum sock is under vacuum.

2. An arrangement for mounting a two stage cryogenic refrigerator into a cryostat as claimed in claim 1 wherein said refrigerator is elongate in an axial direction, and wherein said axle is parallel to said axial direction.

3. An arrangement for mounting a two stage cryogenic refrigerator into a cryostat as claimed in claim 2 wherein said thermally conductive contact piece comprises an arcuate element that at least partially surrounds said first stage of the refrigerator, said arcuate element having an end connected to said bellows structure and a free end opposite said end connected to said bellows structure, and wherein said axle proceeds through said free end of said arcuate element.

4. An arrangement for mounting a two stage cryogenic refrigerator into a cryostat as claimed in claim 2 wherein said thermally conductive contact piece comprises an arcuate body having an end connected to said bellows structure and a free end opposite said end connected to said bellows structure, and wherein said axle proceeds through said end of said arcuate body connected to said bellows structure.