lab notebook

Working notes from ongoing research — written as the work happens, not after. Exploratory and work-in-progress by design: single-trajectory experiments, numbers with stated caveats, dead-ends included. Read them as a record of what was tried and what came out, not as finished results.

Sep 2026

Filament Tracer: what the divertor plate inherits from the outboard midplane

Edge filaments follow the magnetic field, so a whole radial–toroidal plane at the divertor target should be a sheared image of the midplane plane. On Hermes-3 simulations of TCV it is: a rigid toroidal shift finds nothing, the equilibrium field-line map finds it at zero lag, structures wider than ~5 cm are inherited and blob-scale ones are not, mean density and momentum arrive later at the sound speed, and a toroidally equivariant linear map predicts the plate as well as any operator transformer. Three tabs: planes and correlations, a 3-D torus, and a prediction atlas with a pre-registered ridge-versus-GAOT pilot. Movies, captions, and open questions included.

Aug 2026

TCV plasma emulator: what the present evidence supports

A self-contained account of the two-shot dataset, LOLA training procedures, representation choices, rollout calibration, ETKF sensor conditioning, and the physics tests needed before diagnostic rankings can be interpreted as design guidance.

Jul 2026

petch: a first-principles 3-D plasma-etch profile engine — technical evidence pack

Measured plasma fluxes and a material stack in; coupled transport, surface chemistry, self-consistent charging, and a moving 3-D profile out. Reproduces a published SiO₂ trench experiment to 0.19% on the mask opening, measured head-to-head speed against the open-source state of the art, and a preregistered blind-transfer protocol with the held-out data mechanically sealed. Movies, scorecards, and claim boundaries included.

Jul 2026

Emulating TCV edge turbulence: an architecture notebook

Four model families — a deterministic ViT operator, a geometry-aware graph transformer, predictive self-supervision, and latent diffusion — each tried on one Hermes-3/BOUT++ trajectory of tokamak edge turbulence, scored on physics gates rather than pointwise error. The recurring enemy is "the freeze": the collapse of MSE-trained models onto the conditional mean.

Jul 2026

Anchored rollouts: conditioning the emulator on sparse diagnostics

Given the generative emulator of notebook I, what can a realistic set of edge diagnostics (gas-puff imaging, divertor Langmuir probes, reflectometry) actually constrain? Anchored rollouts with synthetic sensors, two misleading signals caught along the way, and a first-pass observability estimate with its caveats stated up front.