This Is the Most Powerful Superconducting Magnet in the World

“One of our missions is to keep pushing this technology as far as it can go,” says one of the magnet's creators.
This is the most powerful superconducting magnet in the world
Image: Argonne National Laboratory/US Department of Energy/Science Photo Library

Powerful magnets are everywhere, from medical equipment to particle accelerators in physics labs. Scientists have long worked on making magnets more powerful, and now a new superconducting magnet has broken the world record for strength.

Researchers from the National High Magnetic Field Laboratory in Florida created a superconducting magnet—which use electric currents to generate a magnetic field—more powerful than any before it. It creates a magnetic field of 45.5 tesla, breaking the previous record of 45 tesla, according to a study published on Wednesday in Nature.


The magnet, nicknamed "little big coil" by researchers, generates these huge magnetic fields by running strong electric currents through cuprate-based coils. The only magnets capable of higher intensities are pulsed magnets, and their fields only last for a fraction of a second, according to a press release from Nature. This new superconducting magnet generates a magnetic field for as long as you run a current through it.

“One of our missions is to keep pushing this technology as far as it can go,” researcher David Larbalestier said in a phone call. “Stronger magnets with more reliability is our mantra.”

For the past 20 years, the highest achievable direct-current magnetic field was 45 tesla. The high-powered hybrid magnets that create this current use so much energy that they are only available in a few labs worldwide, according to the study. They rack up astronomical electricity bills that most labs can’t afford. Instead, researchers travel to special facilities to use these magnets for their experiments. Superconducting magnets require far less power to run, but used to generate weaker fields.

Superconducting magnets have many uses, such as magnetic levitation (which allows trains to float above their tracks), nuclear magnetic resonance and even driving submarines. Larbalestier told Motherboard that the magnetic field essentially functions as an energy source, and researchers can use higher-energy fields to determine the structure of complex molecules.


The design of the new magnet is what makes it so much stronger. The magnet isn’t insulated, which means that the magnet goes from a superconducting state and back to normal quickly and safely.

“We’ve flipped the script,” said Larbalestier. “In the past, researchers put a resistive magnet inside a conventional superconductor. Here we’ve put an unconventional superconductor inside the resistive magnet.”

The materials used are different from other magnets. According to the study, the magnet consists of a stack of 12 pancake coils and is wound with incredibly thin copper oxide superconducting tape. This strong tape can wrap the coils to be super compact, and has only recently been manufactured to be this thin. In the past, cuprate-based magnets have been too fragile, but this new design can withstand fields up to 60 tesla.

These magnets aren’t quite ready to be rolled out to every lab in the country. There are still signs of damage from that 45.5 tesla magnetic field, Larbalestier said, and using it requires a lot of babying and quality control.

Once it does become more stable, however, labs can begin to adopt this record-breaking magnet for their own experiments.

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