S77 — Negative-triangularity δ-scan

S77: Negative-triangularity δ-scan. Design-space study (forward-looking), part of the Kronos MetroVolt 81-analysis validation record.

Register ID

S77

Campaign

Design-space studies (forward-looking)

Status

Design-space study (forward-looking)

S77 addresses the confinement requirement (H98 = 2.28 at the Mode-D baseline) — the largest feasibility bet in the program — through transport physics on the negative-triangularity plasma.

What the register records

Deliberately reported NEGATIVE result: q95(eq) falls with |δ| (4.94 at −0.30 → 3.98 at −0.52), so holding the q95≥5.0 floor reduces admissible current. The frozen δ=−0.30 point sits at the favourable end of the shaping/confinement trade — deeper NT does not buy margin here.

This is a register summary of a deposited analysis; its title and notes quote the deposit as-run, so parameters here may reflect the pre-Mode-D basis where they differ — all operating claims cite the frozen Mode-D point (ratified 24 July 2026). Full input decks, scripts, and output data for every analysis S01–S81 are released openly under CC BY 4.0.