The first plasma discharge of a Compact Torus Central fueling device

Recently, a team led by Dr. KONG Defeng at the Institute of Plasma Physics, CAS (ASIPP) manufacturing the world's first Compact Torus device (EAST-CT) for medium and large tokamak central fueling completed the first plasma discharge. This marks the successful realization of the key mission of the Compact Torus device after seven months of design, construction, installation and testing. The device will be tested on EAST, which will lay a solid foundation for future fusion reactors such as CFETR to verify new central fueling technology.

Central fueling is a crucial issue for the development of the next-step fusion device, such as the China Fusion Engineering Test Reactor (CFETR), since it’s beneficial to increase the pressure gradient of trapped particles, optimize the bootstrap current and improve the tritium burnup rate as well as reduce the requirement of tritium breeding ratio for tritium self-sufficiency. CT-injection is one of the most promising methods for central fueling of large tokamak fusion devices because of its extremely high injection velocity.

In this research, aiming at the characteristics of strong magnetic field and high discharge parameters of EAST Tokamak, the team comprehensively optimized the structural design of the Compact Torus system and improved the construction and installation process. The team also independently designed a set of experimental test platform to simulate the discharge environment of EAST, which provided a reliable guarantee for the optimization of charging parameters. It took seven months to complete the construction of the compact ring device with high efficiency, and successfully realized the first plasma discharge.

For the next step, the Compact Torus R & D team will continue to carry out discharge optimization and develop Compact Torus technology. Through cooperation with domestic and foreign research institutions and universities, the team will promote the rapid application of Compact Torus technology in central fueling and fracture mitigation of fusion reactor, help nuclear fusion research, serve the development of energy technology and innovate the future.

This work is supported by the National Key Research and Development Program of China No. 2017YFE0300500, the Institute of Energy, Hefei Comprehensive National Science Center under Grant No. 19KZS205, the International Partnership Program of Chinese Academy of Sciences no. Y16YZ17271. Users with Excellence Program of Hefei Science Center CAS 2020HSC-UE008. The Compact Torus research team consists of the members from Institute of plasma physics, Chinese Academy of Sciences, University of science and technology of China, Hefei University of technology and Shihezi University.

A review of Compact Torus Central fuelling device for medium and large tokamaks: Compact Torus device and the First-plasma discharge information.(Reported by KONG Defeng)

 Compact Torus host system and test platform

 Members of the compact Torus development team

 First plasma discharge and current waveform