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MAST normalised-beta authority

validation/mast_normalised_beta_authority.py is the normalised-beta admission gate for the canonical disruption channel beta_N. It diagnoses the public FAIR-MAST EFM_BETAN source without guessing a scale, changing its values, or promoting a metadata correction into physical authority.

Definition and metadata boundary

The pinned IMAS Data Dictionary defines beta_tor_norm as

100 * beta_tor * a[m] * B0[T] / Ip[MA]

with unit 1. The pinned FAIR-MAST ingestion mapping gives the same definition for EFM_BETAN, but targets the older IMAS leaf beta_tor_normal. The live Level-2 array has source unit T. These facts identify a metadata conflict; they do not define a physical T-to-1 conversion.

The only non-destructive candidate is therefore to preserve the source values and repair metadata after authority is complete. The gate sets numeric_transform to null, forbids range-based scale inference, and never clamps or discards negative samples.

The source mapping is pinned to the FAIR-MAST ingestion repository. The canonical leaf, definition, and unit are pinned to the IMAS Data Dictionary.

Required authority

Canonical binding requires either primary-source authority for the direct array or an independently reproducible formula route. The reproduction route must bind, on one source-attested alignment:

  • equilibrium.beta_tor, including whether values are fractional or percent;
  • equilibrium.minor_radius, in m;
  • equilibrium.bvac_rgeom, the exact vacuum field used by EFM at the geometric axis;
  • equilibrium.plasma_current_x, including its sign or magnitude convention;
  • equilibrium.time;
  • an equilibrium validity or reconstruction-quality rule; and
  • one-standard-deviation uncertainties plus the covariance policy.

Names, approximate magnitudes, positive majorities, or dimensional cancellation are not substitutes for those declarations.

Real two-shot result

The 2026-07-23 bounded run acquired a fresh SourceObjectManifest-v2 snapshot for MAST shots 30421 and 30424 under the external Samsung datasets tree. It retains minor_radius without resampling and is pinned to source generations 44d2c93f...a32868 and 1da4ee7c...f6b0. The complete manifest has payload digest aba5e048...d196a and records 14,699,129 derived bytes.

The direct beta_N evidence contains 107 finite samples per shot. Shot 30421 has 3 negative and 104 positive finite samples, with an observed range of -13.4791 to 3.9432. Shot 30424 has 4 negative and 103 positive finite samples, with an observed range of -5.8219 to 3.8770. These values are observations, not scale or validity authority.

beta_tor, minor_radius, and the equilibrium timebase are present. The exact bvac_rgeom and fitted plasma_current_x inputs are absent. Both shots remain blocked for that missing formula lineage, the live source-unit and stale-leaf conflicts, unresolved sign/scale and negative-value validity, absent reconstruction-quality authority, and absent one-standard-deviation uncertainty. Canonical binding, training, scientific validation, facility prediction, and control admission all remain false.

The self-digested report is retained as non-public operational evidence. Its payload digest is 6c8e8b4e...c9706a1; its file SHA-256 is 5dc6c759...a425e.

Reproduction

Run the gate only against a verified SourceObjectManifest-v2 root:

python -m validation.mast_normalised_beta_authority \
  --manifest /external/source-v4/source_object_manifest.json \
  --artifact-root /external/source-v4 \
  --shot-id 30421 --shot-id 30424 \
  --json-out /external/l2f12b-authority.json

The report is deterministic and self-digested. A source-member, metadata, shape, time-order, formula-lineage, quality, sign/scale, negative-value, or uncertainty failure keeps canonical_beta_n_binding_admissible false.