China now hosts the world’s most powerful resistive magnet. It produced a magnetic field over 800,000 times stronger than Earth’s. On September 22, at the Steady High Magnetic Field Facility (SHMFF), it sustained a steady field of 42.02 tesla. This narrowly surpasses the previous record of 41.4 tesla set in 2017 at the US National High Magnetic Field Laboratory.
Resistive magnets are made of coiled metal wires. They are widely used in facilities worldwide. China’s new record magnet supports the goal of creating magnets that sustain even stronger fields. This progress could lead to new discoveries in physics, according to physicist Joachim Wosnitza.
The SHMFF’s resistive magnet is open to international researchers. In 2022, the facility’s hybrid magnet produced a field of 45.22 tesla, making it the most powerful steady-state magnet globally.
High-field magnets help reveal hidden properties of advanced materials like superconductors. They can also create or manipulate new states of matter, says Marc-Henri Julien from the National Laboratory for Intense Magnetic Fields in Grenoble, France. Higher fields improve sensitivity in experiments, according to Alexander Eaton from the University of Cambridge.
Physicist Guangli Kuang noted that achieving this record took years of modifications. “It wasn’t easy,” he said.
Despite their advantages, resistive magnets have a significant drawback: they consume a lot of power. The SHMFF’s magnet drew 32.3 megawatts to reach its record field. Eaton points out that researchers need a strong scientific justification for such resource use.
This challenge is spurring the development of hybrid and fully superconducting magnets that use less power. In 2019, NHMFL researchers created a miniature superconducting magnet that briefly reached 45.5 tesla. They are also working on a larger 40-tesla magnet for experiments. The SHMFF is developing a 55-tesla hybrid magnet.
While newer magnets may be cheaper to operate, they also have challenges. They are more expensive to build and require complex cooling systems, says Mark Bird from NHMFL. “The technology is still developing, and costs are unclear,” he adds.
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