HELIUM DILUTION REFRIGERATION SYSTEM

摘要

Helium Dilution Refrigeration System A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self contained pumping system and heaters for operation of the system. A mixing chamber contains 3He and 4He liquids which are precooled by a coupled container containing 3He liquid, enabling the phase separation of a 3He rich liquid phase from a dilute 3He-4He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the 3He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute 3He-4He liquid phase.