WHY THIS MATTES IN BRIEF
Magnets are the unsung heroes of the modern era, they help produce our energy and make engines work, make MRI machines possible and make futuristic transportation technologies like the Hyperloop feasible, and developments in the field drive innovation across a variety of sectors.
If you want to stick something on your fridge, like a car or a small battleship, then you might want to talk to the scientists at the US based National High Magnetic Field Laboratory (NHMFL) because, hot on the heels of the world’s first magnetic wormhole, yes, an actual wormhole, they’ve just build the most powerful superconducting magnet ever and shattered the previous world record. And if you’re wondering why I’m covering the story, well, magnets are important. They’re in everything from the engines in your cars and your vacuum cleaners, and the scanners in your hospitals, and they also make Mach 1 trains like the Hyperloop and, inevitably the 2,500mph Chinese T-Flight train possible. They’re the unspoken heroes of the tech world and without them your car would be nothing more than a hunk of metal clogging up your driveway, that and the fact without them pretty much every boy and girl scout troop with a compass would have been lost in the woods long ago. Sorry starving wolves, no dinner for you today. Thanks magnets.
The NHMFL team’s new magnetic field clocks in at 32 Tesla (no, not the cars, it’s a unit of measurement in this case) in strength. That’s 33 percent higher than the previous record, and 3,000 times stronger than your puny fridge magnet, making this a larger increase than all the improvements in superconducting magnets from the last 40 years combined.
“This is a transformational step in magnet technology, a true revolution in the making,” said MagLab Director Greg Boebinger, “not only will this state-of-the-art magnet design allow us to offer new experimental techniques here at the lab, but it will boost the power of other scientific tools such as X-rays and neutron scattering around the world.”
The People and Technology Behind The New Record
The new magnet is called the 32T, and it’s made of a combination of low-temperature and high-temperature superconductors, materials that conduct electricity frictionlessly, as opposed to a material such as copper, which loses power and generates heat in the process.
Magnets that are made of these resistive materials are called resistive magnets, and they can be very powerful, in fact, MagLab created another record breaking one earlier this year that “only” generated a magnetic field of 41.4 Tesla, but because they lose so much energy, the energy requirements to power them are much higher than what is needed for a superconducting magnet. For example, that 41.4 Tesla magnet takes a whopping 32 megawatts of direct current power to run.
Low temperature superconductivity was first discovered in 1911, but it’s not without limitations. As the name suggests, it only works below a certain temperature threshold, usually around 20 Kelvin (-253.15 Celsius or -423.67 Fahrenheit).
This means that the superconducting magnets that power MRI machines in hospitals require liquid helium to keep the magnet at operating temperature, which, as you’d expect, is a costly solution, but still more economical than the power requirements of a resistive magnet of the same strength.
These low temperature superconductors also stop working at magnetic fields higher than about 25 tesla. But then high temperature superconductivity was discovered by IBM researchers Georg Bednorz and K. Alex Müller in 1986. Not only do high temperature superconductors work at a wider range of temperatures, they also work in stronger magnetic fields.
By combining the two, the team at MagLab were able to create a powerful superconducting magnet that overcomes the limitations of low temperature materials. 32T uses a conventional low temperature superconductor, and a high temperature superconductor called YBCO made of Yttrium, Barium, Copper and Oxygen, which has a critical temperature of about 93 Kelvin (-180 Celsius or -292 Fahrenheit – we told you it was relative).
The magnet took years to design, and the team developed new techniques for insulating, reinforcing, and de-energising the system. Now that they have those techniques, they can try to develop the magnet even further.
“We’ve opened up an enormous new realm,” said Huub Weijers, who oversaw the magnet’s construction, “I don’t know what that limit is, but it’s beyond 100 Tesla. The required materials exist. It’s just technology and dollars that are between us and 100 Tesla.”