Development of a −186 °C cryogenic preservation chamber based on a dual mixed-gases Joule-Thomson refrigeration cycle

► A dual mixed-gases cycle J-T refrigerator was built to reach as low as 75.5 K. ► A cryogenic chamber prototype was developed based on the similar cycle configuration. ► The measured minimum temperature of the cryogenic chamber is about −192 °C. ► This cryogenic chamber has good prospective compared with liquid nitrogen vessels.