MetroVolt operates at normalized pressure βN = 4.33 against the no-wall Troyon limit of 4.5. The deposited MHD programme shows what disciplined ambition looks like: run at the free limit, and hold the wall-stabilised regime in reserve.
Ideal-MHD analyses (MISHKA/MARS-K-class decks, S22/S25) adjudicate the with-wall limit at βN ≈ 5.0, conditioned on plasma rotation and kinetic resistive-wall-mode stabilization — requirements stated, not waved away. The robustness envelope (S79) prices the prize: at βN = 5.0 the same frozen geometry delivers +24% fusion power (2,409 → 2,999 MW) at unchanged confinement quality, with the density limit becoming the next boundary.
High-current beta analysis (KX-9) favours the 42.5 MA mode (βN 4.33 vs 4.96 for the alternative), while the disruption ledger favours lower current — a real trade, resolved by gate adjudication and published as such.
A design that needs its best case to close is fragile; MetroVolt closes at the no-wall limit and treats wall stabilization as upside. For offtakers, that is a +24% power option on the same capital; for physicists, it is a falsifiable claim with the decks already public.
| Operating βN | 4.33 (no-wall limit 4.5) |
| Wall-stabilised limit | βN ≈ 5.0 (S22/S25) |
| Upside at βN 5.0 | +24% Pfus (2,409 → 2,999 MW) |
| Conditions | rotation + kinetic RWM stabilization |
| Next boundary after β | Greenwald fraction 1.30 |