Fangliang Dong

The electromagnetic device of magnets wound by HTS wires, with their irreplaceable strong magnetic field characteristics and simplified cooling requirements, have significant application prospects in the fields of energy, electric power, transportation, medical care, scientific researches, etc. However, limitations such as operating economy, stability, and quench protection issues persistently hinder the real engineering applications of superconducting magnets due to the demanding operating requirements. With the successful industrialization of HTS materials in recent years, the aforementioned issues have become more prominent in the core component HTS magnets.

Fangliang realized the quasi-persistent-current operation mode on closed-loop HTS magnets by achieving ultralow-resistance copper diffusion joints in HTS tapes. In addition, he studied solid-nitrogen cooling technology to replace traditional non-renewable liquid helium cryogen. The operation of magnets no longer relies on the maintenance of external power and cooling supplies. This overcomes the main difficulties both in energizing and cooling in achieving economical and reliable operation of HTS magnets. The above technologies have provided core technical support for the development of on-board superconducting magnets, the key part of future energy-economical 600 km/h-class high-speed maglev trains in China.

Meanwhile, he pioneered a surface shunting technology. Based on the micron-scale distributed energy bypath coated on the magnet surface, the irreversible thermal/mechanical damages due to cascading effect of quenching are successfully suppressed. This validated protection method provides a practical solution for operational stability of the current high-field HTS magnets worldwide. This technology provides important supports for the high-field 1) imaging magnets in high-resolution NMR and 2) fusion magnets the essential component of compact nuclear fusion reactors. And this compact fusion technology was recognized as one of the 10 Breakthrough Technologies by MIT Technology Review in 2022.

The breakthroughs in overcoming bottleneck challenges that are globally faced by HTS magnet applications will continuously drive the vigorous development of HTS-related industries, bringing significant economic and social effects.