A 1.8 K superfluid helium system was developed by a group of scientists from Institute of Plasma Physics (ASIPP), HFIPS of CAS. The system was debugged on October 20th, and successfully produced 1.8 K superfluid helium.
This system, according to the team, is an important part of cryogenic system of the Comprehensive Research Facility for Fusion Technology (CRAFT) Project.
The group developed CRAFT 200 W@4.5 K helium refrigerator before to produce liquid helium. This time, by reducing pressure with sub-atmospheric warm compressors, they obtained 1.8 K superfluid helium.
The system can not only verify the measurement of 1.8 K temperature range, but also carry out the test of 4.5 K-1.8 K sub-atmospheric heat exchangers.
The Cryogenic Engineering and Technology Laboratory of ASIPP spent more than one year to complete the flow design of the system, the design, development, installation and debugging of key components such as sub-atmospheric heat exchanger, and realize the joint debugging of CRAFT 200 W@4.5 K helium refrigerator and sub-atmospheric warm compressors.
"The final test results met the design indicators," said YANG Pengcheng, member of the team.
The successful development and commissioning of the 1.8 K superfluid helium system paved the way for the deep research of the 1.8 K superfluid helium system, and laid a foundation for the construction and operation of the large scale 1.8 K superfluid helium cryogenic system of the fusion reactor.
Test site diagram of 1.8 K superfluid helium system (Image by ZHAO Weiwei)
Temperature curve of 1.8 K cooling process （Image by YANG Pengcheng）