Startorus Fusion, in collaboration with Tsinghua University, has pioneered the world’s first Double-Ring Local Helicity Injection (DLHI) technology, advancing Merging Compression (MC) startup
Startorus Fusion, in collaboration with Tsinghua University, has pioneered the world’s first Double-Ring Local Helicity Injection (DLHI) operation technology. By utilizing injection currents of 2 kA from each of the two plasma guns, it successfully drove a double-ring plasma with a total current of 50 kA. This technology was jointly proposed by Startorus Fusion and Tsinghua University and achieved for the first time internationally. It helps reduce the reliance on central solenoids during the operation of spherical tokamaks and further enhances the performance of spherical tokamaks. Additionally, this technology addresses the long-standing issue of plasma gun arcing in spherical tokamak devices—a problem unresolved in similar international devices—thereby expanding the application scope of plasma guns and significantly increasing their driving potential. Moreover, the successful coupling of DLHI with Merging Compression (MC) startup stably forms the initial configuration of double-ring plasma, effectively reduces the volt-second consumption during the MC startup process, increases the plasma current during MC startup, and contributes to further improving various parameters in the double-ring startup of tokamaks.
Under high magnetic field conditions (0.4–0.8 T), this technology also validated two current-driving scales of Local Helicity Injection (LHI) : it not only verified the current-driving scale derived from helicity conservation, confirming the results from similar international devices and proving theoretical reliability, but also further validated the current-driving scale derived from Taylor relaxation theory. This enhances the experimental verification of helicity injection theory and demonstrates the advanced nature of this operational mode.