Field replaceable cryocooled computer logic unit

Abstract

A cryocooled field-replaceable logic unit for use with a cryogenic cold head such as that of a cryocooler comprises a thermally conductive plate adapted to be disposed in thermal contact with the cold head, a thermally insulating enclosure portion cooperating with the conductive plate to form a sealed enclosure detachable from the cold head, and one or logic chips mounted in the enclosure in thermal contact with the conductive plate. Preferably the conductive plate is attached to the thermally insulating portion through a resilient mounting which forms a recess for receiving the cold head and which is tension-loaded when the logic unit is mounted on the cold head to urge the plate into intimate thermal contact with the cold head. In one embodiment the enclosure receives from an external source a supply of gaseous nitrogen which is liquified by contact with the conductive plate to form a pool of liquid nitrogen in which the logic chips are immersed. In another embodiment plural logic units are detachably mounted on passive cold heads immersed in a cryostat.