Princeton team launches Borealis Fusion, focusing on the magnetic mirror pB11 pathway

Recently, Borealis Fusion, a startup co-founded with the participation of the research team at the Princeton Plasma Physics Laboratory (PPPL) in the United States, announced its establishment. The company has chosen the magnetic mirror pathway, focusing on proton-boron-11 (pB11) neutron-free nuclear fusion technology, aiming to provide cost-competitive clean electricity.

It is understood that Borealis Fusion was jointly founded by five doctoral scholars with backgrounds in physics and engineering from Princeton University: Damien Scott, Ian Ochs, Elijah Kolmes, Tal Rubin, and Alex Glasser. Its core technology originates from the pB11 frontier research led by Princeton University professor Nat Fisch, and the technical team has accumulated deep experience in theoretical analysis, computational modeling, and plasma control.

Compared with the traditional deuterium-tritium (D-T) fusion pathway, the primary reaction of pB11 fusion produces only helium nuclei, generates no neutrons, and does not require reliance on a complex tritium breeding cycle, thereby substantially reducing material radiation damage, equipment maintenance, and decommissioning costs at the source. However, pB11 requires ion operating temperatures far higher than the D-T pathway, and the "helium ash" accumulated in the plasma can cause severe X-ray radiation energy losses.

To solve the problems of "helium ash" accumulation and radiation losses, the team has proposed a conceptual device called PRISM (pB11 Rotating Ion Separation Mirror). This scheme utilizes the open magnetic field line structure of a tandem mirror to achieve efficient expulsion of helium ash, and separates different ions through the centrifugal effect generated by driving intense plasma rotation, thereby ensuring the reactor's energy balance. Currently, Borealis Fusion has obtained venture capital investment from multiple well-known institutions including Breakthrough Energy Fellows and Astera, and is fully advancing self-consistent physics modeling and first-stage validation experiments.