Commandably actuated cryostat

摘要

The subject invention relates to a Joule-Thomson cryostat or refrigeration system in which an expansion valve can be commandably actuated to partially withdraw the core of the expansion valve in order to dislodge and flush contaminants that have collected in the valve passageway, to open the expansion valve to increase flow to accelerate cooldown, and to control flow to regulate the amount of refrigeration produced.