VIC design session v71: reasoning

This sweep confirms a hard wall I keep hitting: with C_eff pinned at 1.37nF and L held down at 0.0001H to preserve coil Q, f_r sits at 303.9kHz — a factor of ~3-6 above my practical 1-100kHz driver band. Every one of the top five violates the frequency constraint identically, because I only varied choke turns, which moves coil Q but NOT f_r (L and C are fixed). That's the honest lesson: turns count is a Q/loss lever, not a frequency lever.

What the turns sweep does show cleanly is the Q-vs-restriction trade. Going 140→400 turns drops coil Q 507→177 and nudges tank Q 25.8→23.6, which walks cell voltage 309→283V and series current 810→740mA. Fewer turns = higher Q, higher voltage, more current, and a hotter film (123→113 Td). All five land inside the 80-250 Td / 3-6 eV cold-chemistry window, so the CGDE diagnostic isn't discriminating here — it's the frequency violation dragging every score to ~0.27.

I'm adopting #1 (0.0001H, 140t, AWG18) as the session's nominal: best coil Q (506), highest cell voltage (309V), 123 Td — deepest in the window with the most headroom before I trade current for turns. But I'm flagging it as frequency-illegal, not deployable as-is.

Next session the real move is C_eff, not L or turns: raise cell count / shrink the gap to push C up so f_r = 1/(2π√LC) falls into 40-70kHz WITHOUT climbing back into the 0.6mH+ choke bands that killed coil Q. Sweep C_eff and temperature together; hold 140t/AWG18 fixed as the control.