Experimental Study of a Helium Sorption Cooler with Low Temperature Fluctuation and Long Hold Time below 1 K

Helium sorption cooler technology is a key means to realize highly reliable low-vibration very low-temperature environments, which have important applications in fields such as quantum computing and space exploration. The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser, developed a reliable-performance helium sorption cooler (HSC), and conducted experimental studies. Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6 MPa helium at room temperature. The low-temperature hold time is 26 h, and the temperature fluctuation is within 0.8 mK. The cooling power of the helium sorption cooler is 1 mW @ 0.98 K @ 3.5 h. Experimental results indicate that when the charging pressure is reduced to 4 MPa, the minimum temperature decreases to 836 mK, and the hold time shortens to 16 h. When the pre-cooling temperature increases from 3.9 to 4.9 K, the hold time is reduced to 3 h.