System for providing cryogenic refrigeration using an upstream pulse tube refrigerator

This invention relates generally to low temperature or cryogenic refrigeration and, more particularly, to pulse tube refrigeration. A system for providing refrigeration to a heat load, especially over a larger temperature range and at a cryogenic temperature, wherein pulse tube refrigeration cools a heat transfer medium to provide higher level refrigeration to a refrigeration fluid, and lower level refrigeration is provided to the refrigeration fluid using a non-pulse tube system.