AC suppression
UntestedSame RMS voltage, but AC instead of DC. Thrust should drop dramatically.
What this test isolates
Premise. (κ−1)/κ Maxwell stress points in a fixed direction under DC. Under AC the force direction flips with the field, time-averaging close to zero for symmetric waveforms.
Why it matters. If AC at the same RMS gives the same thrust as DC, the dominant mechanism isn't electrostatic — it's something rectifying like ion drift.
Variable. Excitation type (DC vs sinusoidal AC, same RMS)
Hold constant
- Same V_rms, same Gravitor, same atmosphere
Prediction. Thrust under AC is < 20% of thrust under DC at the same RMS voltage.
How to run this test
- 1
Get an HV AC source
Variac → step-up transformer, or a function-gen + HV amplifier.
- 2
Match RMS to a DC reference
If DC was 20 kV, run AC at 20 kV RMS.
- 3
Run both back-to-back
Discharge between runs to clear residual polarisation.
Pitfalls
- !AC at 60 Hz against a thermally massive dielectric heats it asymmetrically — keep durations short.
- !Rectified AC isn't AC — verify the waveform on a scope.