Researchers at ETH Z\u00fcrich have built the most powerful miniature superconducting magnets ever demonstrated, potentially opening the door to affordable, lab-scale high-field science.<\/p>\n
Generating magnetic fields above 40 tesla has traditionally required room-sized machines that guzzle megawatts of electricity. A team of researchers at ETH Z\u00fcrich has just changed that equation \u2014 fitting a magnet capable of hitting 42 tesla into a device small enough to hold in one hand, running on less than a single watt of power.<\/p>\n
The results, published in Science Advances<\/a>, describe two compact all-high-temperature superconducting (HTS) magnets built from rare-earth barium copper oxide, or REBCO, tape. One reached 38 tesla using two pancake-shaped coils. The other, with four coils stacked together, hit 42.3 tesla \u2014 a field strength that previously required massive, power-hungry infrastructure found only at a handful of national laboratories worldwide.<\/p>\n Putting numbers in perspective<\/p>\n To put those numbers in context: a standard hospital MRI machine operates at 1.5 to 3 tesla. The previous benchmark for an all-HTS magnet stood at 26 tesla. The world-record steady-state magnet<\/a>, a 45.5-tesla behemoth at the U.S. National High Magnetic Field Laboratory, consumes more than 20 megawatts of power and requires an enormous infrastructure footprint.<\/p>\n In contrast, the ETH Z\u00fcrich magnets use thousands of times less power and have coil volumes over 1,000 times smaller, while coming close to that record.<\/p>\n The engineering trick<\/p>\n The main challenge was winding REBCO tape around a very small bore \u2014 just 3.1 millimeters in diameter, roughly the width of a pencil. Standard winding methods need at least 14 millimeters to prevent cracking the superconducting layer. The team created a special method that moves the connection point between coils to the outside of the bore, keeping the tape intact despite the tight bend.<\/p>\n