Decreased Fabrication Cost of High Performance Super Conducting Magnets

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Decreasing the cost of manufacturing high performance super conducting magnets is important for many industries including NMR and MRI magnets. Researchers at the Princeton Plasma Physics Lab have invented a new method to simplify the Nb3Sn coil winding process to reduce organic insulation and liquid He3 cooling requirements. At the same time, this process increases winding pack density and structural integrity.


Coils are first wound on a steel coil form using bare wire without the conventional glass sleeve insulation. After heat treatment, structural reinforcement is applied to the exterior of the coil winding pack, removing the need for vacuum pressure impregnation. Prototype testing at the Plasma Physics Lab show over 80% fraction of critical current reached while significantly reducing the coil fabrication cost. 



•       Reduced organic insulation required

•       Reduced He3 cooling required

•       Elimination of expensive and error-prone VPI process

•       Increased winding pack current density

•       Maintained coil structural integrity

•       Maintained high coil performance 



Stage of Development

Prototype devices have been created and tested.


Intellectual Property & Development Status

Patent protection is pending.


Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.



Chris Wright

Princeton University Office of Technology Licensing • (609) 258-6762  •



Yuhu Zhai is a senior mechanical engineer at the Princeton Plasma Physics Laboratory. He received the M. Sc. and Ph.D. from the University of Florida in Gainesville, FL in 2001 and 2003 respectively with a major in Engineering Mechanics and minor in Electrical and Computer Engineering. He worked as a chief design engineer for the North China Electric Power Design Institute on the design and construction of thermal power plants in Beijing before coming to the United States. He was a postdoctoral research associate in the Electrical and Computer Engineering of Duke University from 2003 to 2006, focused on space plasma physics and remote sensing of the Earth’s magnetosphere. He became a scientist and superconducting magnet engineer at the National High Magnetic Field Laboratory, Tallahassee, FL since 2006 where he developed the Florida Electro-Mechanical Cable Model for understanding performance degradation of ITER Nb3Sn cable-in-conduit conductors (CICCs) under thermal and mechanical loading. He joined PPPL in 2010 and became the chief analyst for the design of ITER diagnostic first wall and led the multi-physics analysis effort for US ITER diagnostics and port plug engineering. He was also involved in the final design of ITER in-vessel coils and became an expert in plasma disruption related electromagnetic simulations for component design of the NSTX Upgrade project at PPPL. Dr. Zhai served as session chairs for the SOFE and TOFE meetings. He also served as the Gust Editor for the IEEE Transactions on Plasma Science. He was a key note speaker at the 2017 and 2018 Low-Temperature Superconductor Workshops. He has authors or co-authored over 60 refereed journal papers and conference presentations.


Princeton Plasma Physics Laboratory           

Princeton Plasma Physics Laboratory (PPPL) is a United States Department of Energy National Laboratory managed by Princeton University. PPPL is collaborative national center for fusion energy research. The Laboratory advances the coupled fields of fusion energy and plasma physics research, and, with collaborators, is developing the scientific understanding and key innovations needed to realize fusion as an energy source for the world. An associated mission is providing the highest quality of scientific education.


Patent Information:
For Information, Contact:
Chris Wright
Licensing Associate
Princeton University
Yuhu Zhai