Space and Physics
PUBLISHED
Magnets are a crucial technology in our modern life. There are magnets in pretty much all electronics, most household appliances, and in a variety of places, from doors to school bells. The most powerful magnets are used in both advanced scientific studies and cutting-edge applications, and they are usually large and need a lot of electricity to be able to produce those strong fields. Now, a team has just developed one that is a game-changer.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.They produced two miniature magnets using all-high-temperature superconducting (HTS) materials wound with rare-earth barium copper oxide (REBCO)–coated conductor tape. The configuration with two pancake coils reached 38 tesla, and the one with four reached 42 tesla. Let’s put those numbers into context.
The world’s most powerful steady-state magnet, at 45.5 tesla, is located at the U.S. National High Magnetic Field Laboratory, and it is a sizable device that requires a lot of electricity. The world’s most powerful resistive magnet is in China and has a strength capacity of 42.02 Tesla. The new device is comparable to those, but a lot more compact and cheaper to use.
“Despite the much higher current density, they consume a few thousand times less power and require a coil volume over 1000 times smaller than that of the 45.5 T hybrid magnet,” the authors wrote in the paper.
The Earth’s own magnetic field is between 25 and 64 microtesla, making this magnet around 1 million times stronger than the whole magnetic field of our planet. And you can easily hold it in your hands, though you might need some or a lot of protection.
First of all, this is significantly higher than the limit considered safe by the US Food and Drug Administration (FDA), with most MRI machines operating up to 4 tesla (although one has been approved that works up to 7 tesla). Secondly, it will be really cold. While the superconductors are high-temperature, this is still well below zero, just less than -195 °C ( -320 °F).
If you are curious about the strongest human-made magnet, it was an incredible 1,200 tesla. Not only would it be capable of bending steel doors, but it also destroyed the lab it was housed in once it was turned on. The risk of pushing limits!
The strongest natural magnets are magnetars, a type of neutron star formed in superluminous supernovae. They possess magnetic fields of the order of 10 to 100 billion tesla, so strong that if there were one halfway between the Earth and the Moon, it would wipe out all credit cards on Earth – and you do not want to know what would happen to the atoms in your body if it started getting closer.
The study is published in the journal Science Advances.
