The Super-X Divertor

A Super-X divertor lengthens and spreads the exhaust leg to ease heat load, enabling the detachment Kronos relies on. Its flux expansion is within demonstrated range.

What

A long-legged, high-flux-expansion divertor

Benefit

Spreads and radiates exhaust heat

Kronos need

Flux expansion F_x ~ 3–4×

Precedent

Within MAST-U's demonstrated 5–10×

A Super-X divertor is an advanced divertor geometry that routes the exhaust field lines along a long outboard leg with strong magnetic flux expansion, spreading the exhaust heat over a much larger surface and making it far easier to radiate the power away before it reaches the target. The MAST-U tokamak has demonstrated the concept.

Kronos MetroVolt relies on Super-X flux expansion to achieve the detachment its power exhaust requires. The good news the design carries honestly: the flux expansion it needs (F_x ~ 3–4×) sits within the 5–10× range MAST-U has already demonstrated, so this is an application of a proven geometry rather than an extrapolation. The remaining question is sustaining detachment at the required SOL conditions — one of the ranked open items.