A continuous cryogenic pellet injection system for tokamak fueling has been developed by a joint research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences. It overcame technical challenges related to cryogenic ice formation, pellet cutting, and pellet launching.
Cryogenic pellet injection is a cutting-edge technique in fusion research, where hydrogen isotopic gases are condensed into solid ice pellets, which are then accelerated and injected into plasma. This method offers deep particle injection and high fueling efficiency, making it a crucial technology for the future of fusion reactors. It is considered a key core fueling technology for next-generation fusion devices such as the International Thermonuclear Experimental Reactor (ITER), the China Fusion Engineering Test Reactor (CFETR), and the European Demonstration Fusion Reactor (EU-DEMO).
The newly developed system can launch pellets of up to 12 mm³ in volume per shot, with an adjustable firing frequency between 1 and 10 Hz. It can also achieve a maximum pellet velocity of over 300 m/s, matching the performance of international counterparts. The system passed its factory acceptance test on the first attempt.
This system is set to be installed on the EAST Tokamak, where it will support high-density and high-confinement plasma experiments, according to the team.
Photographs and Test Results of the Pellet Injection Fueling System (Image by HOU Jilei)
