On June 18, the Lower Hybrid Current Drive system (LHCD) — a critical subsystem of the Comprehensive Research Facility for Fusion Technology (CRAFT) — successfully passed expert testing and was officially accepted, marking a significant milestone for the project.

Developed by researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, the LHCD system is now fully localized, with all components manufactured domestically. 

As one of the 19 core systems of the facility, the LHCD plays an essential role in advanced fusion research. It is responsible for driving and maintaining the toroidal plasma current in tokamak devices, regulating current distribution, heating plasma electrons, supporting the current ramp-up phase, suppressing edge-localized modes, and optimizing heat flux on the divertor.

The researchers overcame several major technical challenges, including the design of fusion reactor oriented antenna, long-distance low-loss power transmission, and reliable and safe system operation.

"We have achieved all major technical goals," said Prof. LIU Liang, team lead for the project. "That includes center frequency of 4.6 GHz, up to 4 megawatts of microwave source power, running stable pulse operations for over 100 seconds, finishing a reactor oriented antenna design, and making real breakthroughs in long-distance low-loss power transmission, mode conversion, and safe, reliable system operation."

In collaboration with domestic partners, the researchers developed core components such as 500-kilowatt klystron, 500-kilowatt circulator. These technologies also show great potential for use in other fields, including microwave heating, wireless communication, healthcare, and electronic engineering.

The successful tvalidation and acceptance of the LHCD system provide a robust foundation for the development of next-generation radio-frequency heating systems in future fusion reactors.

CRAFT LHCD System (Image by CAI Qimin)