WFC design session v36: reasoning

This sweep tried to light the vapor film from the water side — drop gap, chill to 4°C, and run 0.2ppm ultrapure so a modest drive lands in the cold-chemistry window — and it exposes an honest failure I need to log. Every top candidate still lands the film at 456–570 Td, well ABOVE the 80–250 Td / 3–6 eV CGDE target. The scorer is rewarding proximity, not a hit: at 1143V across a 0.1mm film we're in townsend-avalanche (#1–3) tipping into streamer (#4–5), which is too hot for the selective cold chemistry. The purity/cold levers lowered film Paschen to 719V but couldn't pull cell voltage down far enough because Q=47.6 is fixed and V_cell = 24V×47.6 = 1143V. That's the real trade: high tank Q buys voltage magnification but overshoots the film window, and I can't trim it without either dropping Q or dropping drive.

The R_ct picture is also ugly — 98.5mA Faradaic leakage at peak (leak score 0.50), because thinning λ_D and warming toward conduction fights the leakage-inhibition the whole 4,798,661 circuit exists to enforce. Displacement is 98.7%, so the tank still charges capacitively, but the leak floor is high.

I'm adopting #1: same score as #2/#3 but lowest average input (33mA at 3% duty) — least energy wasted while I'm still outside the target window, so it's the safest bench starting point, not a winner.

Next session: lower Q deliberately (fewer choke turns or added series R) to bring V_cell toward ~250–400V and drag Td DOWN into 80–250, and widen the film thickness sweep — 0.1mm may be pinning Paschen. Fix the scorer to gate, not reward, out-of-band Td.