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MAST saddle-modal authority

validation/mast_saddle_modal_authority.py is the saddle-modal admission gate for the canonical disruption channels n1_amp and n2_amp. It verifies the source field, timebase, and toroidal geometry but deliberately does not execute a Fourier reduction while the row identities and calibration policy are incomplete.

Source and transform boundary

The pinned FAIR-MAST ingestion mapping names a twelve-row field source, ASM/SAD/OUT, with ordered source channels ASM_SAD/M01 through ASM_SAD/M12. It also exposes lower, middle, and upper saddle-coil geometry from a separate geometry file. Each geometry surface contains twelve toroidal polygons in degrees.

The candidate transform is fixed as

A_n(t) = (2/N) * abs(sum_k B_k(t) * exp(-i*n*phi_k)))

for n=1 and n=2. This formula is only a candidate until the field rows and geometry rows have an authoritative join. A matching row count or an evenly spaced geometry is not that join.

The complete upstream mapping is pinned by commit and whole-file SHA-256:

Required authority

Canonical modal binding requires all of the following to be persisted in the source lineage:

  1. a released geometry revision tied to the exact geometry-value digest;
  2. the ordered identity of every field row;
  3. the field-to-geometry row join and the selected lower, middle, or upper saddle set;
  4. field calibration and one-standard-deviation uncertainty; and
  5. baseline, saturation, missing-value, and bad-channel policies.

No observed phase, amplitude, or regular spacing may supply these missing declarations.

Real two-shot result

The generation-pinned SourceObjectManifest-v2 snapshot for MAST shots 30421 and 30424 contains all three 12 x 28 geometry arrays. Their circular polygon centres agree at 15°, 45°, through 345°. The field arrays have shapes 12 x 38261 and 12 x 39821; their timebases are finite and strictly increasing.

Only field rows 1 through 8 contain finite values. Rows 9 through 12 contain no finite sample in either shot. The source metadata also preserves only the first UDA row name, does not attest which geometry vertical set joins the field, gives no positive standard uncertainty or baseline/bad-channel policy, and describes the geometry as development revision 0 with an empty creator commit. The array-level geometry unit is the compound string SI, degrees, m, while the pinned mapping declares the toroidal component in degrees.

The result is therefore blocked. No modal amplitude is calculated by the gate, and the signal-binding and replay reports keep both canonical channels inadmissible. Training, scientific validation, facility prediction, and control admission remain false. The byte-reproduced report is retained as non-public operational evidence; its file SHA-256 is b321b337...b2919 and its payload digest is 0785c0e3...88177.

Reproduction

Run only against a verified SourceObjectManifest-v2 root:

python -m validation.mast_saddle_modal_authority \
  --manifest /external/source-v4/source_object_manifest.json \
  --artifact-root /external/source-v4 \
  --shot-id 30421 --shot-id 30424 \
  --json-out /external/l2f12c-authority.json

The output is deterministic and self-digested. The gate records shapes, finite counts, geometry-value identities, and circular centres, but never emits raw arrays or derives n1_amp or n2_amp while any authority blocker remains.