Physics Overview of Infinity Two

Type One Energy is developing a high magnetic field, optimized stellarator for a direct path to fusion energy [1]. Infinity Two is a fusion pilot plant (FPP) baseline plasma physics design consistent with a set of buildable coils, divertor solution, required shielding, and a blanket with sufficient tritium breeding ratio. We describe the physics properties of Infinity Two, a quasi-isodynamic stellarator, optimized appealing to a max-J approach (J being the second adiabatic invariant), and designed to operate at high plasma density and high magnetic field. In this poster, we will discuss the physics properties that make Infinity Two a suitable FPP candidate, namely its reduced Neoclassical and turbulent transport, small bootstrap current, low alpha-particle losses to the first wall, magnetohydrodynamic (MHD) stability, and attainable operation point with high fusion gain.

[1] C. C. Hegna, et al. The infinity two fusion pilot plant baseline plasma physics design. Journal of Plasma Physics, 91(3):E76, 2025.