Re: Streamer formation on the scope...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Terry,

Thanks, Terry - these are really excellent measurements! They only begin
to hint at the complexities of gas discharge phenomena. And when looking
at these (and future) current measurements, we'll need to be very
careful about distinguishing between the types of discharges that will
be involved. In particular, we should see evidence for, and differences
between, currents associated with initial breakout, corona, streamer
flashes/streamer propagation, and leader displacement currents.
Hopefully, you'll see ALL of these when similar tests are done at higher
voltages with larger radius conductors. 

It's interesting that your measurements show most current spikes flowing
"into" the HV electrode (negative polarity), while Greg's (and Streamer
theory) show the opposite. Suspect the difference may lie with that fact
that initial corona breakout (for SMALL diameter electrodes) is a bit
easier with negatively polarized electrodes. The preferred electrode
polarity should be positive for actual streamer propagation from larger
diameter electrodes. I wonder if you are actually seeing the first pulse
of what would have become Trichel Pulses if we applied a steady state
voltage stress under these conditions. You're also seeing significant
displacement current flow into/out of the wire electrode. Still, LOTS to
digest from these measurements...

Thanks again for some really informative measurements!

Best regards,

-- Bert -- 
-- 
Bert Hickman
Stoneridge Engineering
"Electromagically" (TM) Shrunken Coins!
http://www.teslamania-dot-com

Tesla list wrote:
> 
> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi All,
> 
> Tonight I hooked up my fiber-optically coupled current probe to the top of
> the OLTC and made some "small" streamer measurements.  Admittedly, I did
> all this pretty fast and loose ;-))
> 
> http://hot-streamer-dot-com/temp/P9050002.jpg
> 
<SNIP>
> 
>         Terry