Vignesh Gopakumar
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  • Goal
  • Acceptance criteria (fixed in the brief before work started)
  • Tasks
  • Against the criteria
  • Deviations

M2 · Training data

In progress

Goal

Produce the data the surrogates of M3 are trained on: fluxes from a first-principles turbulence model, sampled over the operating space of each machine, stored as immutable, versioned datasets with provenance. The brief requires the sampling to cover spherical-tokamak conditions: the transport network used in M1, QLKNN, was trained at a fixed aspect ratio of 3 and does not.

Acceptance criteria (fixed in the brief before work started)

  1. The dataset loads.
  2. Its provenance validates.
  3. The sampled domain is documented and plotted against the intended operating space.

M2 has no human gate in the brief. The kinetic ranges were approved by the owner before any dataset was generated (OQ-16).

Tasks

task state log
turbulence code: TGLF (GACODE, Apache-2.0) built, checked, timed; CGYRO built for spot checks done entry 16
geometry ranges measured on MAST-U (FreeGSNKE) and ITER (TORAX) equilibria done (OQ-15) entry 17
kinetic ranges, species and αMHD cap per machine done, approved (OQ-16) entry 17
Latin hypercube datasets, MAST-U and ITER, 105 cases each done (version 1) entry 17
sampled domain plotted against the operating space done datasets
high-flux cases explained (K-019) open
active learning near critical gradients not started
QuaLiKiz driver (Tier A) not started
Tier B drivers behind the tier flag not started; needs access

Against the criteria

criterion where it stands
loads both datasets load through the library’s loader, which recomputes each file’s hash (100000 of 100000 cases completed, all six fluxes finiteC-071, 100000 of 100000 cases completed, all six fluxes finiteC-072)
provenance validates each file’s SHA-256 matches its provenance record; the generator commit is recorded with a clean tree; a tampered file is refused (unit test)
domain plotted figure; input by input MAST-U 0.72 (triangularity) to 0.94 (q); ITER 0.63 (q) to 0.94 (triangularity shear)C-076. Wider than the measured set jointly (K-018)

Deviations

  • TGLF only, so far. The brief lists drivers for TGLF and QuaLiKiz (Tier A) and for Tier B codes. Version 1 uses TGLF alone.
  • One dataset per machine (owner, 2026-10-02), rather than one sampling space.
  • Rejection by αMHD in the sampler, not in the brief: without it, independent draws give pressure gradients far beyond ballooning stability (OQ-16).

© Copyright 2026 Vignesh Gopakumar

 
 
Code and first draft by Claude (Anthropic), working to a brief by Vignesh Gopakumar, who reviewed and approved this page. How this is built · Tokamak Toolkit home