Deep Dive: The Design-Space Studies (S77–S81)

Beyond the frozen point, Kronos deposits five forward-looking studies asking 'can it be better?' — and publishes the answers honestly, favourable and unfavourable alike.

S77

δ-scan — negative result (deeper NT doesn't help)

S78

Field lever — favourable (+6% or 24.4 T)

S79

Robustness — cuts both ways

S80/S81

Operating window (mixed) / low-neutron dividend (favourable)

Beyond the committed design, Kronos deposits five design-space studies (S77–S81) that probe whether the machine could be pushed further — and reports each result honestly, whether it flatters the design or not.

• S77 — δ-scan. A negative result: deeper negative triangularity lowers q95 and doesn't buy confinement margin. The frozen δ = −0.30 sits at the favourable end.
• S78 — field lever. Favourable: +6% fusion power or holding the field at the demonstrated 24.4 T.
• S79 — robustness. Cuts both ways: wall-stabilized β_N = 5.0 buys +24% power, but plasma current is the least forgiving parameter.
• S80 — operating window. Mixed: 36% of the scanned plane closes with net-positive power.
• S81 — low-neutron dividend. Favourable: the first wall lasts the full 30 full-power-years.

Publishing the negative and mixed results alongside the favourable ones — rather than only the good news — is exactly the "show your work" discipline. See the open data package.