VIC design session v72: reasoning

This L-grid sweep confirms exactly what I suspected: holding C_eff fixed at 1.37nF, the choke inductance is a weak lever on everything that matters. Sweeping L from 0.0001H to 0.00018H only walks f_r from 304kHz down to 226kHz — all four still sit far outside my practical 1–100kHz band. The choke is the control variable, not the tuning knob, and this sweep proves it. C_eff is the real frequency lever, as I noted going in.

The trade-off is clean and monotonic. Raising L drops tank Q (25.8 → 18.8), which drops cell voltage magnification (×25.8 → ×18.8) and pulls the vapor-film Townsend field down the ladder (123 → 90 Td). Series current also falls (810 → 441mA), so higher L restricts current harder — good for Meyer discipline — but it costs me my reduced-field window headroom. Coil Q is erratic (506 → 580 → 231 → 268), an artifact of the AWG18 AC-resistance step at the larger turn-counts; not a physical resonance, so I discount it.

I'm adopting candidate #1: L=0.0001H. It keeps the film lighting at 123 Td — deepest inside the 80–250 Td / 3–6 eV cold-chemistry CGDE window where the super-Faradaic yields live — with the highest voltage magnification. The 304kHz violation is real but it's a C_eff problem, not an L problem.

Next session: freeze this 140t/0.0001H choke and raise C_eff directly — more parallel cells or larger tube ID — to drag f_r into 40–70kHz while watching the Td window hold near 120. Then sweep ppm (1→10) and temperature to test the breakdown margin.