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Re: Sparks to ground

Hi Richard,
             Interesting observations....

> It has been stated on this list that one an arc contacts ground that the 
> resonator Q goes into the hamper to near zip.
> 
> I was reviewing some frame by frame video hits of maggey #11-E and note 
> that the arc channel develops over an extended period of time!
> 
> I note a spark approaching the heavily grounded aluminum siding on my 
> house.  The contact occurrs, let us say, at t0, in frame, f0.  The arc 
> channel is fairly dim, but contact is made and the arc channel is 115" 
> long point to point.  In the next frame, f1, (1/30 second later) the 
> channel doubles in brightness.(as measured by my light meter (spot 
> reading).  In frame f2 the arc channel increases in brightness by another 
> 40% or so over the preceeding frame.  In frame f3, the channel retains 
> about the same brilliance (white hot) as in f2 frame.  In frame f4, the 
> channel starts to reduce its brightness and is about 65% of f2s level.  
> Frame f5 shows a greatly reduced channel intensity and is just about 10% 
> below that of f0s level.  In frame f5, The channel is just a faint mist 
> of ionized vapor.  Frame f6, shows the channel to have disappeared.
> 
> Assuming 400 BPS (which is my normal break rate), This means that the 
> system has energy pops at the rate of about 13 pulses per video frame. so 
> we see that from time of contact to max brighness,(more or less), we 
> actually sent in about 52 energy pulses.  Is the electronic Q of the 
> resonator system this slow to respond?!!  Energy delivery to the arc 
> channel was consistently on the increase over this long period 
> (~120,000 usec).
> 
> The rise to max channel current is rather slow, compared to the 
> extinguishing of the channel which never takes more than 2 video frames 
> (1/15 sec-60,000usec).
> 
> I am making no judgments here, only reporting observational fact.

In response to your question, yes, I think it is. Until the 
ionization is approaching a low resistance the Q does remain pretty 
high. In my experience, Q drops in proportion to the degree of 
ionization and power dissipation. Corona alone doesn't sink very much 
energy at all and I think a weakly ionized channel is not too far 
removed from corona alone. I have scoped several beat envelopes 
occurring during corona production and have a series of photographs 
just taken off the scope (to be posted when developed) that show the 
result of greater and greater loading. Things do seem to happen in 
slow motion. In my experience, establishing a good arc always takes 
time unless the discharge point is close enough for the arc to be 
struck immediately. It might be worth trying that and checking the 
difference.

Malcolm