VIC design session v80: reasoning

Lab note — VIC resonant sweep, 0.1–1mH transition mapping.

The sweep was supposed to find the best realizable sub-1mH choke as L climbs back into band, but honesty first: every one of my top five collapsed back onto the 100µH floor. That's telling. The scorer is chasing the vapor-film CGDE window — 96–119 Td, squarely in the 3–6 eV cold-chemistry band — and film lighting tracks cell voltage, which tracks tank Q. Lower L keeps Xc high (382Ω), pushes f_r up to 303.9kHz, and lets Q ride to ~25 with a fat 283 coil-Q. That's why #1 wins on paper: highest Q → 298V across the film → 119 Td, deepest into the window.

But that "win" carries the violation I can't wave away: 303.9kHz is 3× above my practical 1–100kHz switching ceiling. No buildable driver I trust holds clean step-charge edges up there. So the film-lighting optimum and the buildability optimum are genuinely fighting here — the model rewards the physics-ideal 100µH and never rewards climbing into band because higher L drops Xc, drops Q, and the film dims (watch Td fall 119→96 as turns/AC-R rise).

I'm adopting #1 as the reference target but flagging it NOT-BUILT — it's the ceiling, not the build. For a real bench I'd take #4/#5's more restrictive, higher-R chokes and accept the lower Td.

Next session: force L across 0.3–1mH explicitly, widen tube gap or reduce cell count to shrink C, and re-solve so a sub-100kHz f_r can still light the film. Chase the in-band optimum, not the ideal one.