World's strongest steady magnetic field generated in China
Scientists in China have set a new world record for the strongest steady magnetic field ever generated on Earth. The hybrid magnet managed to produce a field measuring 45.22 Tesla (T), which is over a million times stronger than the planet’s own.
The record was set at the Steady High Magnetic Field Facility (SHMFF) in Hefei, China, using a magnet with a hybrid design that’s been operating since 2016. The structure includes a resistive magnet sitting in a 32-mm (1.3-in) gap in the center of a superconducting magnet, allowing the two to join forces to produce an incredibly strong magnetic field.
On August 12, the hybrid magnet produced a record-breaking steady-state magnetic field of 45.22 T with a power input of 26.9 MW. Of that, the resistive magnet contributed 34.22 T, with the superconducting ring chipping in the remaining 11 T. This breaks the previous world record of 45 T set way back in 1999 by MagLab in the US.
“To achieve higher magnetic fields, we innovated the structure of the magnet and developed new materials,” said Professor Kuang Guangli, academic director of the High Magnetic Field Laboratory at SHMFF. “The manufacturing process for the Bitter discs [the magnets in the center] was also optimized.”
This new record is specifically for a steady magnetic field, but other types have reached higher strengths. In 2019 a similar hybrid setup peaked at 45.5 T, but that was only relatively briefly. In 2018 a Japanese team managed to generate a magnetic field with an astounding 1,200 T – for about 40 microseconds, before part of the instrument exploded. Needless to say, that one isn’t ready for primetime just yet.
The new steady magnetic field facility, however, is much more practical, the team says. It’s ready to be used for a range of scientific experiments, with access granted for institutes and universities around the world.