Strength of US High-Magnetic-Field Science is Waning, Academies Report Warns

The National Academies released a consensus report on Aug. 13 that recommends federal agencies fund construction of several new world-leading magnets and rapidly increase support for the development of wire technologies within the next two to three years. European and Asian countries have caught up to the U.S. in magnet technology and these steps would help the U.S. regain the lead, the report argues.

High magnetic fields are essential for progress in fusion science, medicine, materials science, fundamental physics, and more, the report states. They enable compact fusion energy sources, more powerful particle colliders, more sensitive magnetic resonance imaging (MRI) systems in hospitals, and the discovery of new quantum states of matter.

“It is hard to see how progress can be made in some of these areas without major efforts in the development of high-temperature superconducting wires and magnets,” the report states.

The report was written by a committee chaired by physicist Peter Littlewood, a former director of Argonne National Lab. It is the latest in a series on high-magnetic-field science and carries forward some of the previous recommendations. Inadequate budgets, the lack of a national agenda, and the lack of a robust commercial industry for key resources are cited as potential reasons why those recommendations from the last report in 2013 have not yet been addressed.

Although the National High Magnetic Field Laboratory (NHMFL) in Tallahassee, Florida, remains a world-class facility, the report observes, other countries have fielded competing capabilities.

“Over the past decade, provision of similar facilities in Europe, China, and Japan has grown, often following the U.S. model, with headline capabilities that now match that of the United States,” the report states.

Building and coordinating new magnets

With this backdrop, the report recommends the National Science Foundation fund the construction of new magnets at the NHMFL to surpass the lab’s current records of magnetic field strength. “Moonshot” efforts such as building an all-superconducting 40 Tesla magnet would cement U.S. leadership in magnetic resonance, it adds.

Another of the suggested projects is a large-bore demonstrator magnet with a strength of at least 14 Tesla, with joint federal funding led by the National Institutes of Health. The magnet would be sized to fit all parts of the human anatomy to maximize research potential of extremely sensitive functional MRI and would serve as an important technology demonstration, said co-author Peter Roemer at a report release briefing.

“It’s one thing to sit there and imagine what you’re going to build with the wire on paper, but it’s a whole other thing to find out the real problems in building something,” said Roemer, a former MRI engineer at GE Healthcare. This magnet would help designers “get 80 to 90% of the way there,” he added.

The report also highlights how European countries have spent significant funds to build high-field nuclear magnetic resonance (NMR) instruments and make them widely accessible to researchers and industry. The U.S. would need around twelve such instruments to match Europe’s level, the report states. Furthermore, though centralized facilities in the U.S. such as the NHMFL are well-funded, the country has many “decentralized” facilities that depend on user fees, limiting researcher access.

The report recommends creating a consortium of high-field NMR instrument sites across the U.S., funded and partially coordinated by NSF, NIH, and the Department of Energy to maximize impact, “similar to what the worldwide competition has established.”

Ramping up support for wire innovation

The report recommends NSF and DOE “double” their support for developing high-temperature superconducting wires, though it does not specify the type of support, financial or otherwise.

High magnetic fields are achieved by passing large currents through metal wires and most of today’s superconducting magnets use niobium-titanium wire. The more powerful magnets needed to enable future technologies, such as muon particle colliders, will require niobium-tin or high-temperature superconducting wire, the latter of which does not currently have a large-scale commercial source in the U.S. The report adds that certain high-temperature superconductor materials contain rare-earth elements largely sourced from China, and the optimal wire for high-field pulsed magnets is sole-sourced from RusNano, a Russian state-established and funded company.

Demand for high-temperature superconductor materials in the fusion field is driving some development and support from industry. However, the resulting wire advancements may not apply to other research fields, such as particle physics and condensed matter physics, the report states. Therefore, it recommends that NSF, DOE, and NIH create collaborative programs to guide magnet and wire development for multiple applications.

Addressing helium shortages for researchers

The report emphasizes how liquid helium is essential to maintain low temperatures for superconducting magnets. Its supply has been limited by high demand across many industries, the sale of the U.S. Helium Reserve, and geopolitical instability.

The resulting price volatility is difficult for researchers to navigate with fixed budgets, the report states. Superconducting magnets across the U.S. have been decommissioned due to lack of helium access, and some university administrators have expressed reluctance to hire faculty and researchers in areas that require helium.

Accordingly, the report recommends giving researchers preferred access to helium that is extracted from federal lands. It also proposes the U.S. establish a new helium reserve for emergency use, classify helium as a critical material, further fund helium recycling systems, and research materials and designs that reduce or avoid helium use.

“The use of liquid helium has no substitute in condensed matter physics research, where it is a critical material for achieving the lowest temperatures necessary for cutting-edge discoveries,” the report stresses.