VIC design session v51: reasoning

Notebook — VIC resonant sweep, seam-closing run (2.6–4.0mH/choke gap)

I set out to fill the 5.2–8.0mH total-inductance seam between my prior arms and watch f_r drop into the 60–78kHz band against the fixed 1.37nF cell. The arithmetic holds: 6mH total lands near 55kHz, 5.2mH near 62kHz, so the band crossing sits right at the low edge of my target — the seam closes where I expected, and those candidates would clear the 1–100kHz practical band cleanly.

But the scorer didn't hand me those. The top five all collapse back onto the 0.1mH physics anchor, resonating at 303.9kHz — outside the practical band — because the film diagnostic dominates the score. That anchor is what lights the vapor film hardest: 104–120 Td, squarely inside the 3–6eV cold-chemistry window, at 262–301V across the 0.1mm film. The higher-L seam candidates resonate politely but evidently don't drive Td as hard, so they lose on the CGDE metric that matters most.

That's the real trade-off this session exposed: Q and low-frequency compliance pull one way, film ignition pulls the other. Candidate #1 (220 turns, tank Q 25.1, coil Q 322, 120 Td) I'm adopting only as a scoring reference — I will NOT build it, because 303.9kHz violates my band and the 0.1mH choke offers no current restriction.

Next session: rerun the 5.2–8.0mH arm but log Td explicitly per candidate, so I can find the highest inductance that still clears 100 Td while sitting in 60–78kHz. That's the honest sweet spot — I don't yet have it.