Single-Torus-Liquid-Metal-Coil fusion device to obtain all stellarator and tokamak configurations [PPPL M-1059]

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Non-Confidential Brief

Single-Torus-Liquid-Metal-Coil Fusion Device to Obtain All Stellarator and Tokamak Configurations

Princeton Docket # 24-4079-1


Researchers at the Princeton Plasma Physics Laboratory (PPPL) have proposed a method for the design of fusion devices (tokamaks and stellarators) that achieve magnetic confinement of plasmas with electromagnetic coils made of a single torus coil. Torus single coil design allows archiving all the possible magnetic field configurations which is very useful for comparing the performance of different stellarators. The conductive torus itself can be made from large 2D super conducting sheets that are not yet commercially available, or a solid metal conductor such as copper. 

This design allows a way to use liquid metal inside a shell as the coil as well. An electric current is to be applied in the liquid metal inside the shell, and this current would generate a magnetic field that achieves the confinement desired for the device. This approach allows the design of a toroidal confinement system that does not require the construction of separate coils, but merely the installation of voltage sources at specific locations of the toroidal shell. The disclosed approach offers further advantages for reactor operation, as it could operate as a cooling system – tritium breeder - coil set combination in a single liquid-metal system. This combination of systems leads to significant reductions in manufacturing costs, both for research facilities and for future fusion power plants.



  • Fusion energy researcher and reactor design


  • Simplified reactor design at reduced cost


Intellectual Property Status

Patent protection pending. See provisional application here.


Chris Wright

Princeton Plasma Physics Laboratory •


Patent Information:
For Information, Contact:
Chris Wright
Head of Technology Transfer
Princeton University
Egemen Kolemen
Francisco Saenz Castro
Dario Panici
Richard Majeski