Contact: Ulf Trociewitz
TALLAHASSEE, Fla. — The National High Magnetic Field Laboratory is developing new magnet technology aimed at enabling the next generation of groundbreaking biomedical research. With a new $2.4 million grant from the National Institutes of Health, the lab’s Applied Superconductivity Center will demonstrate that a cutting-edge high-temperature superconducting material can be used to build a nuclear magnetic resonance (NMR) magnet.
NMR is the technology behind magnetic resonance imaging, or MRI, which uses strong magnets to see inside the human body. At much higher magnetic fields, the technique can be used to closely examine biological processes, including the structure, dynamics, and interactions of proteins. Higher-field NMR is opening new frontiers in biomedical research, and helping scientists develop new ways to treat disease.
The new NIH grant aims to demonstrate a powerful NMR magnet that could become the basis for more commercially viable systems available outside of large national research labs, expanding high-field NMR research.
The heart of the new magnet will use a high-temperature superconducting wire known as Bismuth-2212 (Bi-2212). First discovered in 1988, Bi-2212 can carry electricity with near-zero resistance at temperatures below -307° Fahrenheit. It has become one of the most popular conductors for high-field magnet technology because it can be made in lengths of more than a kilometer and consistently carries very high currents. Several kilometers of wire with high current density must be tightly wound into coils to create a powerful electromagnet.
A cross-section of Bismuth-2212 superconducting wire. The dark dots are the filaments that carry current with zero resistance.
In this project, several of those coils will be stacked together and nested inside a low-temperature superconducting magnet made by Oxford Instruments. This will allow the combined magnets to reach fields of up to 30 tesla, much more powerful than a standard hospital MRI at 1.5 tesla.
The work will tap into the “broad expertise of NHMFL scientists and engineers in building high field magnets and magnetic resonance equipment for biological and biomedical applications,” according to Dr. Ulf Trociewitz, the principal investigator on the project.
“It will also involve students and post-docs as a commitment to educating and training the next generation of magnet researchers,” Trociewitz said.
One big challenge will be ensuring the mechanical strength of the magnet, which must be able to endure enormous forces pulling on it during operation. Another hurdle will be achieving the very high homogeneity, or stability, needed for NMR operation. While Bi-2212 shows great promise of producing a uniform field, there is still a lot to learn from coils wound with it, Trociewitz says.
Two high-field magnet test coils (left) made of Bismuth-2212 alongside a spool of the superconducting wire.
The MagLab has long spearheaded high-field magnet development, including for MRI and NMR. The lab’s 21 tesla (900 MHz) all-superconducting magnet has been the world’s strongest MRI system since 2004. The lab also built a 36-tesla magnet that has provided a world-record field for NMR since 2017. The lab’s 36-tesla system, however, combines a superconducting magnet and a power-hungry resistive magnet which requires the MagLab’s unique infrastructure to operate.
A commercially viable high-field NMR magnet would need to achieve its high fields without the massive power infrastructures available exclusively at national research labs. The ASC is partnering with magnet industry leaders like Cryomagnetics and Oxford Instruments to advance these goals as well. There is a strong desire for high-field systems at various locations across the United States.
“That makes this R&D work very timely”, Trociewitz says.
