>The plasmoid looks a whole lot like the final "flame" that
>reaches the top of my high powered Jacob's ladder just before the
>arc extenguishes and restarts at the the bottom. When the flame
>extenguishes at the top, I have noticed that sometimes a small por-
>tion of the arc flame will "detach" from the main body of the arc for
>a split second before vanishing.
I took some pics once of a Jacob's ladder I set up on my 10kVA
pig. It seemed to me that the plasma from the arc was sustaining
freely at the top for an instant, and when I looked at the pics,
sure enough that's what was happening. There were bits of plasma of
various sizes freely floating at the top, and some shots showed
them decaying while the next arc had restarted and traveled up from the bottom.
So for such a typical setup as a medium-powered Jacob's ladder,
it's possible for plasma to "dwell" for ostensibly dozens of
milliseconds. I would guess that introducing an order of magnitude
of additional mass into the arc (water) would increase the mass of
the plamsa, and thus allow an order of magnitude increase in the "dwell" time.
-Phil LaBudde