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RE: Streamer growth filming ( CoronaSpherePuzzle)

Hi Jeff, Antonio & List,

Jeff, I must disagree, though concede there is activity below the "ability
to see" threshold.

I do believe we will see something such as is observed in natural lightning
strikes:

 1.) Faint leader(s) with stepped branch offshoots (probing for a return
path) 

 2.) followed by a bright high current channel power event
       (through that path established by the leader that encountered
       a significant return path connection)
       which then drains all available energy from the cloud (or top TC
terminal)
       to include the stored energy remaining in any substantial arc
branches
    (note: I believe branches may tend to have some built in isolation as a
function
     of their higher XL from independent high frequency (~2 to ~50MHz) self
oscillation)

     What a feeling to observe an offshoot leader lose brightness just as
the main channel
       ignites through the leader established path with a full charge in the
gas tank ! 
         Likely to need ~10's nS resolution/discrimination ability
         requiring a great deal of ingenuity to capture 
         (Nothing is impossible !)
         The Single Shot mode is a good place to start, 
             subsequently (after bugs worked out) applied to increasing bang
rates 
             to observe discharge growth as a function of increasing break
rate.

(make a wish) instrumenting my DC TC: .1uF 7kVdc 2.5J vacuum switch gap, 
Lpri-spiral-1/4cu=6.7uH  Lsec-#24awg6.3x19"=28mH k=.2 Ctorus+dist=25pF

I would be most pleased to instrument simultaneously a capture in the Single
Shot mode:
(single shot mode control allows good synchronization of event monitors)

  Vfield-Ctop-proximity, Vfield-arc-proximity, Vgap
  Ipri=cap,  Isec, Iarc, 
  still photo (integral) of the >1uS arc event (to compare with electrical
signature)
  video of the arc event with fastest practical frame rate (search
frame-frame for revelation)

Antonio:
I believe disconnected corona self oscillates at very high frequency (short
arc), though
   with a less substantial channel due to much lower current density
consequently
   radiating little (background noise and short disconnected
radiator/antenna)
   making the very high freq oscillations harder to observe and instrument.
  (just how does one isolate/instrument a single disconnected corona
emanation ????)

Itop probe: energy xfr in single corona is too small to see in Ctop charge
path from Sec
I don't yet have a fiber isolated probe that can monitor terminal current
 but even that can not measure faint corona due to integration of the many
independent
 disconnected discharges on the large plate of the capacitor/top load 
  (I measure point to point connected discharge current by placing a 
     clamp on current probe xfmer around a 1/4" Cu tube ground arc return
lead) 
 - the larger ~200kHz charging from the Secondary would likely be all that
is observable
 - Lsec appears to serve as a choke to isolate connected discharges 
       (source of discharge is stored energy from low Z Cap not higher Farc
Z, L)
 - during disconnected corona there is a constant swishing back and forth of
charges
   but top terminal charging activity predominates instrumented observation
       until a connected discharge occurs

Regards, Dale
Redondo Beach, CA, USA

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, November 02, 1999 6:59 AM
To: tesla-at-pupman-dot-com
Subject: Re: Streamer growth and filming it all (was Re: Corona and
Sphere- Puzzle -addition)

Original Poster: "Jeff W. Parisse" <jparisse-at-teslacoil-dot-com> 

Terry (et. al.),

> What I must wonder is if 8000 FPS is fast enough?  

I bet what we really want to see is invisible.

Once the ion channel is lit brightly enough for a camera
(or human eye for that matter) to see, it's already been
established and therefore of less scientific value than
the actual streamer formation data that we seek.

Established arc channel data is valuable information and
can help us explore arc formation theories, however, the
question we seek to answer is "What factors affect the
growth of arc channels?". I suspect that the phenomenon
we seek to observe is invisible.

Jeff W. Parisse
www.teslacoil-dot-com