China sets world record with 800,000x more magnetic field than Earth’s

Chinese scientists have reportedly created the world’s strongest resistive magnet, which produced a steady magnetic field of 42.02 Tesla. This magnetic field is more than 800,000 times stronger than Earth’s.

Made from coiled metal wires, resistive magnets are commonly used in magnet research facilities worldwide. The achievement is seen as another major breakthrough for the CHMFL (High Magnetic Field Laboratory, Chinese Academy of Sciences), following its 2022 success with the world’s most powerful 45.22-tesla hybrid magnet. 

According to the institution, after nearly four years of relentless efforts, scientists and engineers refined the magnet’s structure, optimized its manufacturing process, and achieved a steady magnetic field of 42.02 tesla with a power supply of 32.3 MW, surpassing the 41.4-tesla record set by the US National High Magnetic Field Laboratory in 2017.

Record-breaking magnet could lead to novel physics discoveries

According to Joachim Wosnitza, a physicist at the Dresden High Magnetic Field Laboratory in Germany, China’s record-breaking magnet sets the stage for developing reliable magnets capable of sustaining even stronger magnetic fields. These advancements could pave the way for researchers to uncover unexpected new physics.

High-field magnets are essential tools for exploring the hidden properties of advanced materials like superconductors, which can carry electric current without generating waste heat at very low temperatures. These powerful magnetic fields also provide opportunities to observe entirely new physical phenomena and manipulate states of matter, offering valuable insights into condensed-matter physics.

According to Alexander Eaton, a condensed-matter physicist at the University of Cambridge, high magnetic fields are especially useful for experiments requiring highly sensitive measurements, as they enhance resolution and make detecting subtle phenomena easier. 

Each additional tesla greatly improves the precision of these measurements, enabling clearer insights into elusive physical effects.

Guangli Kuang, a high magnetic field specialist at SHMFF (Chinese Academy of Sciences’s Steady High Magnetic Field Facility), explained that the team dedicated years to refining the magnet to reach this new record, noting that the achievement was far from easy.

New study highlights advantages of resistive magnets

Resistive magnets, though older technology, can maintain high magnetic fields for longer durations compared to newer hybrid or fully superconducting magnets. They also offer the advantage of quickly ramping up their magnetic fields, making them highly versatile for experiments. 

However, their major drawback is the significant power consumption, which makes them costly to operate. For instance, the SHMFF’s resistive magnet required 32.3 megawatts of electricity to achieve its record-breaking field, necessitating a strong scientific justification for such resource use.

The challenge of high power consumption is spurring the development of hybrid and fully superconducting magnets that can produce high magnetic fields with less energy. In 2019, NHMFL researchers created a small superconducting magnet that briefly achieved a 45.5-tesla field and are now working on a larger 40-tesla superconducting magnet for experiments. Meanwhile, the SHMFF team is constructing a 55-tesla hybrid magnet. 

While these newer magnets are expected to be cheaper to operate than resistive magnets, they also have their own challenges, such as higher construction costs and complex cooling systems.