China claims world record for strongest stable magnetic field

16 Aug 2022

The hybird magnet achieved a stable field of 45.22 tesla. Image: SHMFF

Scientists in China claim to have broken a record that was set in 1999, though other magnets have managed to briefly achieve similar results over the years.

Scientists in China claim to have set a new world record for the most powerful steady magnetic field.

At the Steady High Magnetic Field Facility (SHMFF) in China, scientists said they used a hybrid magnet to achieve a stable field of 45.22 tesla, which is the measurement of magnetic flux density. For context, a fridge magnet only has roughly 0.001 tesla.

This breaks the world record of 45 tesla set in 1999 by a hybrid magnet at the National High Magnetic Field Laboratory (MagLab) in the US.

The hybrid magnet used in China is composed of a resistive insert, which is nested in a superconducting outer ring that has a bore of 32mm.

The research team constructed the magnet in 2016 and managed to achieve a result of 40 tesla initially.

Prof Kuang Guangli is the academic director of the High Magnetic Field Laboratory at the Hefei Institutes of Physical Science, of the Chinese Academy of Sciences (CHMFL). He explained the upgrades the team worked on to achieve more powerful results.

“To achieve higher magnetic field, we innovated the structure of the magnet, and developed new materials,” Guangli said in a statement. “The manufacturing process of the Bitter discs was also optimised.”

The record-breaking magnet is one of 10 magnets currently operated and deployed by CHMFL, where the SHMFF is based.

A computer graph showing three different coloured lines, which all link to the power of a hybrid magnet.

A graph showing the hybrid magnet’s results. Image: SHMFF

A batch of records

The team said the 45.22 tesla record is an important milestone in the development of magnetic technology, for both China and the world.

MagLab still holds the record for the most powerful superconducting magnet, however. The US laboratory claimed to have achieved a record of 45.5 tesla in a trial run in 2019, but could only briefly achieve these results.

In 2018, a Japanese team claimed to generate a magnetic field of 1,200 tesla for 40 microseconds, but the power caused a portion of the scientific instrument to blow up.

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Leigh Mc Gowran is a journalist with Silicon Republic