Closed-Cycle Cryogenic Refrigeration System

Abstract

A multi-stage closed-cycle cryogenic refrigeration system is disclosed. The system includes an adsorption refrigerator having a multi-chambered pump unit that can be flexibly configured in the context of the cryogenic refrigeration system resulting in a more efficient design that has a smaller overall size than prior systems and other advantages.

What is claimed is: 
     
         1 . A multi-stage cryogenic refrigeration system, comprising:
 an outer housing;   a first cooling stage comprising a cryostat within said housing; and   a second cooling stage comprising a sorption refrigerator;   said sorption refrigerator including an evaporator, a condenser, and a sorption pump assembly;   said sorption pump assembly including a plurality of interconnected sorption pump chambers in fluid communication with one another, each sorption pump chamber substantially defined by respective sorption pump chamber walls and containing an amount of adsorbing material therein.   
     
     
         2 . The system of  claim 1 , said sorption pump chambers further sharing a structural cap coupled to said respective sorption chamber walls and providing said fluid communication between said sorption pumps by way of fluid passages interconnecting said plurality of sorption pumps to one another. 
     
     
         3 . The system of  claim 1 , at least some of said plurality of sorption pump chambers being connected in fluid communication with one another in a series configuration so that a discharge of a first sorption pump chamber is directed to an inlet of a second sorption pump chamber in said pump assembly, with a terminal one of said sorption pump chambers discharging to said condenser of said sorption refrigerator stage. 
     
     
         4 . The system of  claim 2 , said shared structural cap comprising a machined metal cap enclosing respective volumes of each of said plurality of sorption pump chambers while permitting said fluid communication through said passages in said shared structural cap. 
     
     
         5 . The system of  claim 2 , said shared structural cap comprising a machined copper cap containing said fluid passages and having a plurality of mechanical coupling points to mechanically secure said shared structural cap to a respective plurality of sorption pump chamber walls. 
     
     
         6 . The system of  claim 1 , said plurality of sorption pump chambers being configured about a coupling tube providing fluid coupling between one of said sorption pump chambers and said evaporator of said sorption refrigerator. 
     
     
         7 . The system of  claim 2 , said sorption pump assembly and its shared structural cap being mechanically configured to substantially surround and accept a cold head of said cryostat substantially centrally disposed within said housing of said system. 
     
     
         8 . The system of  claim 7 , said cold head of said cryostat being axially disposed within said sorption refrigerator's sorption pump assembly. 
     
     
         9 . An adsorption refrigerator, comprising a sorption pump assembly having a plurality of sorption pump chambers, each sorption pump chamber mechanically capped by a shared structural cap, said shared structural cap including fluid communication ports and passages permitting fluid flow between at least two of said plurality of sorption pump chambers through said ports and passages. 
     
     
         10 . The refrigerator of  claim 9 , further comprising a condenser and an evaporator in fluid communication with at least one of said plurality of sorption pump chambers. 
     
     
         11 . A cryogenic cooling apparatus, comprising:
 an outer housing;   a sorption pump assembly comprising a plurality of sorption pump chambers;   a condenser; and   an evaporator;   said condenser including an inter-connected network of fluid passageways coupled to said plurality of sorption pump chambers by respective ports in said condenser so that a fluid may be exchanged between said evaporator, said condenser and said plurality of sorption pump chambers.