Abstract: A control system for an actively cooled cryogenic biological preservation unit wherein vapor flow into or out of the unit or a proxy thereof is sensed by a flow sensor signaling a controller which modulates cryocooler refrigeration into the unit.

Abstract: A method of storing biological samples in which the biological samples are stored in a stack within a vessel interior of an insulated vessel. A pool of liquid cryogen is maintained within the vessel interior by condensing cryogenic vapor boiled off of the pool of liquid cryogen with a cryocooler having a cold finger. The cryocooler and cold finger are positioned so that a cold heat exchanger of the cold finger is in thermal contact with the cryogenic vapor and is positioned above the stack, so as to also maintain a temperature difference within the insulated vessel, between a bottom region of the stack and a top region of the stack, of no greater than about 65K.

Abstract: A refrigeration system especially useful for refrigerating biological samples wherein a cryocooler, such as one employing a pressure wave from a pressure wave generator, is used to generate refrigeration for cooling liquid coolant or purging fluid, which is employed within hollow structures bordering an enclosed space of a storage unit or within the storage space of a storage unit and is subsequently cleaned of contaminants purged from the storage space.

Abstract: A system for the cryogenic preservation of biological material having a dedicated cryocooler integrated with an insulated vessel and preferably a membrane separator which processes feed air for supplying gaseous nitrogen into the insulated vessel for condensation by refrigeration provided by the dedicated cryocooler.

Abstract: A cryogenic biological preservation unit and method of operation wherein the atmosphere within the unit is sealed from the outside atmosphere by pressure maintenance provided by varying amounts of refrigeration from a cryocooler and by a sealed lid employing pliable polymeric material maintained in compression.

Abstract: A cryogenic biological preservation unit having a removable lid and an integrated cryocooler positioned apart from, or within a fixed portion of, the lid and which provides refrigeration to the upper portion of the interior of the unit which also contains a pool of liquid cryogen and at least one biological sample preferably positioned above the pool of liquid cryogen.

Abstract: A refrigeration system especially useful for refrigerating biological samples wherein a cryocooler, such as one employing a pressure wave from a pressure wave generator, is used to generate refrigeration for cooling liquid coolant or purging fluid, which is employed within hollow structures bordering an enclosed space of a storage unit or within the storage space of a storage unit and is subsequently cleaned of contaminants purged from the storage space.

Abstract: A refrigeration system especially useful for refrigerating biological samples wherein a cryocooler, such as one employing a pressure wave from a pressure wave generator, is used to generate refrigeration for cooling liquid coolant or purging fluid, which is employed within hollow structures bordering an enclosed space of a storage unit or within the storage space of a storage unit and is subsequently cleaned of contaminants purged from the storage space.

Abstract: A method for providing cooling to superconducting cable wherein pressurized liquid cryogen is passed into a vacuum vessel, which is maintained at a lower pressure by a vacuum pump, and a portion of the liquid cryogen is flashed to produce cooled liquid cryogen. The evacuating energy combined with the pressurized liquid produces a pressure gradient which serves to provide a continuous supply of cooled liquid cryogen for providing cooling to the superconducting cable.