Evolution of axisymmetric tandem magnetic mirrors

The tandem magnetic mirror concept, characterized by a linear geometry where electrons and ions bounce between strong magnetic fields at the polar ends, is being modernized with the advent of high-temperature superconducting magnets. Realta Fusion is developing the 'Hammir' device, utilizing a novel plasma operation contours — POPCONs — technique for the central cell to overcome historical radial transport limitations that have dogged mirror machines since the 1980s.

Detailed integrated end-plug modeling suggests that an axisymmetric tandem mirror utilizing modern neutral beams and HTS magnets can achieve a fusion gain — Q — greater than 5. The linear architecture is inherently simpler than toroidal systems, with open ends that allow direct energy conversion and simplified maintenance access.

Realta emphasizes that the tandem mirror is specifically optimized for delivering high-grade industrial process heat rather than exclusively large-scale electricity, a market segment with lower grid-integration barriers and higher effective value per megawatt than baseload power.