Major breakthrough of fully superconducting magnet technology in China: ASIPP develops 35.1 T steady-state superconducting magnet
On September 26–27, 2025, a fully superconducting magnet developed by the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) achieved a steady-state central magnetic field of 35.1 T. This breakthrough, a pivotal advancement in global fully superconducting magnet technology, surpassed the previous world record of 32.4 T and set a new international benchmark.
Steady-state high magnetic fields serve as a pivotal extreme condition for modern frontier scientific research, playing an indispensable role in uncovering novel quantum phenomena, elucidating material microstructures, and advancing technologies such as nuclear magnetic resonance and magnetic confinement fusion. Currently, the generation of high-intensity magnetic fields primarily relies on water-cooled magnets, superconducting magnets, or hybrid systems combining both. Among these, superconducting magnets, by virtue of their zero-resistance property, demonstrate marked advantages in achieving high-intensity steady-state fields, particularly in terms of energy efficiency, temporal stability, field homogeneity, and spatial dimensions.1 However, low-temperature superconductors (LTS) are limited in upper field capability, a constraint overcome by high-temperature superconductors (HTSs) like REBCO tapes. The prevailing technical route for fields above 30 T thus employs a hybrid architecture: the external LTS provides a background field, combined with an HTS insert for additional field boost. This technical route was pioneered by the US National High Magnetic Field Laboratory with a 32 T magnet in 2018,2 advanced by Chinese groups, including a 32.35 T system developed by the Institute of Electrical Engineering, Chinese Academy of Sciences in 2019,3 and a 32.4 T magnet demonstrated by ASIPP in 2024.4 Currently, ambitious projects such as the 40-T initiative at the US Magnet Laboratory and Europe’s Super EMFL program demonstrate the global pursuit of ever-higher magnetic fields.
The 35.1 T fully superconducting magnet consists of a coaxially nested REBCO HTS insert within an LTS background magnet, as shown in Figure 1. The HTS insert, serving as the primary source of the magnetic field, is subjected to extreme electromagnetic forces exceeding 800 MPa. Consequently, a pivotal design objective was to enhance both the electromagnetic and mechanical safety margins of the insert, as the critical current of its conductors is highly susceptible to degradation under such intense magnetic fields and mechanical stress. The magnet was tested in liquid helium at 4.2 K. The LTS outer magnet provided a background field of 12.6 T, and the REBCO insert contributed 22.5 T, resulting in a combined central field of 35.1 T. The system maintained stable operation for 30 min before a controlled discharge was performed, as shown in Figure 1. This test result confirms the successful overcoming of critical challenges associated with stress management and multi-physics integration at unprecedented field levels.
This breakthrough signifies a major international advancement in ultra-high-field fully superconducting steady-state magnets, coupled with the realization of autonomous control over essential materials, processes, and manufacturing technologies. It thereby provides a core technological foundation for the development and enhancement of high-field scientific instruments, contributing significantly to the progress of high-field science both in China and across the globe.
Funding and acknowledgments
This work was supported by in part by the Institute of Energy, Hefei Comprehensive National Science Center under grant no. 21KZS207, in part by the Comprehensive Research Facility for Fusion Technology Program of China under grant no. 2018-000052-73-01-001228, and in part by the National Natural Science Foundation of China under grant 52307037. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
