Palm-sized magnet joins world's most powerful coils for first time

Researchers at ETH Zürich have developed the most powerful miniature superconducting magnets to date, achieving magnetic fields above 40 tesla in a palm-sized device consuming less than one watt of power. Utilizing rare-earth barium copper oxide (REBCO) tape, the team constructed two compact high-temperature superconducting (HTS) magnets: one generating 38 tesla with two pancake-shaped coils, and another reaching 42.3 tesla with four stacked coils. These magnets dramatically reduce size and power consumption compared to traditional high-field magnets, which require room-sized infrastructure and megawatts of electricity, such as the 45.5-tesla magnet at the U.S. National High Magnetic Field Laboratory that consumes over 20 megawatts. The key engineering breakthrough involved winding REBCO tape around a very small 3.1-millimeter bore without damaging the superconducting layer, achieved by relocating coil connection points outside the bore and employing a no-insulation winding method with full-coil solder