Cryogenic vacuum break thermal coupler

Abstract

A novel thermal coupler apparatus and method to couple a cryocooler or another cooling device to a superconducting magnet or cooled object allows for replacement without a need to break the cryostat vacuum or to warm up the superconducting magnet or other cooled object. A method uses a pneumatic actuator for coupling, and a retractable mechanical actuator for uncoupling. Mechanical closing forces are balanced between the intermediate temperature and low temperature cooling surfaces and do not transfer to the cooled object. The pneumatic actuator provides permanent control under mechanical closing forces in the thermal coupling.

1 . A coupler for thermally coupling a cooling device having at least one cooling stage, to an object to be cooled, the coupler comprising:
 a. a cold station configured to couple with a cold stage of a cooling device and configured to connect with an object to be cooled;   b. mechanically rigidly connected to the cold station, an actuator support, between which and the cold station, the cold stage of the cooling device fits, movably;   c. a coupling actuator arranged to apply substantially equal and opposite forces to the cold stage and the actuator support, thereby forcing the cold stage from an uncoupled configuration into a coupled configuration, with the cold stage contacting the cold station, without any force being applied to the object to be cooled;   d. a cooling device vacuum enclosure shaped and sized to house a cooling device vacuum around the cooling device, comprising the cold station; and   e. a cooled object vacuum enclosure, shaped and sized to house an object to be cooled, comprising the cold station, arranged to house a cooled object vacuum that is hydraulically independent from the cooling device vacuum.   
     
     
         2 . The coupler of  claim 1 , further wherein the cold stage contacts the cold station without any force being applied to the cooling device. 
     
     
         3 . The coupler of  claim 1 , further wherein the cold stage contacts the cold station without any force being applied to the cooling device vacuum enclosure. 
     
     
         4 . The coupler of  claim 1 , further wherein the cold stage contacts the cold station without any force being applied to the cooled object vacuum enclosure. 
     
     
         5 . The coupler of  claim 1 , further wherein the cold station is configured to connect fixedly with an object to be cooled. 
     
     
         6 . The coupler of  claim 1 , further comprising, thermally coupled to the cold stage, an indium gasket. 
     
     
         7 . The coupler of  claim 1 , the actuator comprising a pneumatic actuator. 
     
     
         8 . The coupler of  claim 7 , the pneumatic actuator comprising a plurality of pneumatic actuators, arranged to operate in parallel. 
     
     
         9 . The coupler of  claim 7 , the pneumatic actuator comprising a plurality of pneumatic bellows, arranged to operate in parallel. 
     
     
         10 . The coupler of  claim 1 , the actuator support comprising a surface arranged substantially facing and opposite the cold station, the actuator comprising a linearly extendible member, coupled to the actuator support surface and pushing the cold stage of the cooling device, toward the cold station, upon energization. 
     
     
         11 . The coupler of  claim 1 , further comprising a releasable couple that releasably couples the cold stage with the coupler. 
     
     
         12 . The coupler of  claim 11 , the cold stage comprising a device circumferential flange, the releasable couple comprising a coupler circumferential flange, connected to the cold station, the device flange and the coupler flange being shaped and arranged so that:
 a. with the cooling device in a first rotational position, translation of the cold stage relative to the coupler is limited to a range of inserted positions; and   b. with the cooling device in a second rotational position, translation of the cold stage relative to the coupler is free to move beyond the range of inserted positions.   
     
     
         13 . The coupler of  claim 11 , the releasable couple comprising a clutch. 
     
     
         14 . The coupler of  claim 1 , the cooling device comprising a cryocooler. 
     
     
         15 . The coupler of  claim 1 , the object to be cooled comprising a magnet. 
     
     
         16 . The coupler of  claim 7 , the pneumatic actuator comprising an actuator that uses helium gas as a source of actuation. 
     
     
         17 . The coupler of  claim 1 , further comprising:
 a. an object to be cooled; and   b. an apparatus coupled functionally to the object to be cooled.   
     
     
         18 . The coupler of  claim 17 , the object to be cooled comprising a magnet. 
     
     
         19 . The coupler of  claim 17 , the apparatus coupled functionally to the object to be cooled comprising a magnetic resonance imaging apparatus. 
     
     
         20 . The coupler of  claim 1 , further comprising a cooling device. 
     
     
         21 . The coupler of  claim 20 , the cooling device comprising a cryocooler. 
     
     
         22 . The coupler of  claim 1 , further comprising a retraction actuator, coupled to the cold stage, which retraction actuator is a different actuator from the coupling actuator, the retraction actuator arranged to move the cold stage from the coupled position to an uncoupled position. 
     
     
         23 - 45 . (canceled) 
     
     
         46 . A method to thermally couple a cooling device having at least one cooling stage to an object to be cooled, the method comprising the steps of:
 a. providing a thermal coupler comprising:
 i. a cold station connected with the object to be cooled and configured to couple, with a cold stage of the cooling device; 
 ii. mechanically rigidly connected to the cold station, an actuator support, between which and the cold station, the cold stage fits, movably; 
 iii. connected to the cold stage, at least one wing extension configured to fit through at least one corresponding opening in the actuator support; 
 iv. an engagement actuator arranged to apply substantially equal and opposite forces to the at least one wing extension of the cold stage and the actuator support, upon energization, thereby forcing the cold stage from an uncoupled position, toward and into a coupled position, contacting the cold station, without any force being applied to the object to be cooled; 
 v. a cooling device vacuum enclosure shaped and sized to house a cooling device vacuum, around the cooling device, comprising the cold station; and 
 vi. a cooled object vacuum enclosure, shaped and sized to house an object to be cooled, arranged to house a cooled object vacuum that is hydraulically independent from the cooling device vacuum; 
   b. introducing the cooling device into the cooling device vacuum enclosure, such that the at least one wing extension passes through the corresponding opening in the actuator support and positioning the cold stage of the cooling device in an uncoupled position between the actuator support and the cold station;   c. rotating the cooling device so that the at least one wing extension is opposite the actuator; and   d. energizing the actuator, so that it engages the wing extension, thereby forcing the cold stage from an uncoupled position, toward a coupled position, contacting the cold station, without any force being applied to the object to be cooled.   
     
     
         47 . The method to couple of  claim 46 , the actuator comprising a pneumatic actuator, the step of energizing the actuator comprising increasing the pressure of a gas provided to the actuator. 
     
     
         48 . The method of  claim 46 , the step of providing a thermal coupler further comprising, providing an indium gasket, bonded to the cold stage. 
     
     
         49 . The method of  claim 46 , the actuator comprising a pneumatic actuator, the step of energizing the actuator comprising increasing the pressure of helium gas provided to the actuator. 
     
     
         50 . The method to couple of  claim 46 , further comprising the step of establishing a vacuum within the cooling device vacuum enclosure. 
     
     
         51 . The method to couple of  claim 46 , further comprising the step of activating the cooling device. 
     
     
         52 . The method to couple of  claim 51 , the step of activating the cooling device taking place before the step of energizing the actuator. 
     
     
         53 . The method to couple of  claim 51 , the step of activating the cooling device taking place after the step of energizing the actuator. 
     
     
         54 . The method to couple of  claim 46 , the step of providing a coupler comprising the step of providing a retraction actuator, coupled to the cold stage, which retraction actuator is a different actuator from the coupling actuator, the method to couple further comprising the step of energizing the retraction actuator to move the cold stage from the coupled position to an uncoupled position 
     
     
         55 - 62 . (canceled)