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Re: big plasma ball








Tesla List <tesla-at-pupman-dot-com> on 19.04.2000 05:24:12

To:   tesla-at-pupman-dot-com
cc:    (bcc: Marco Denicolai/MARTIS)
Subject:  Re: big plasma ball



>Original Poster: "Bill Noble" <william_b_noble-at-email.msn-dot-com>
>
>as you figure, are you accounting for 15 pounds per square inch, or
>144X15=2160 pounds per square foot of pressure as you evacuate this thing?
>if you figure the surface area of your 9 ft sphere, you will see that you
>have one heck of a lot of pressure to hold off -

In my experience you don't need to evacuate to extreme vacuum e.g. a plasma
ball
to have it refilled and working.

I had my plasma globe filled with neon a week ago: first I made as much vacuum
as I could with an old refrigerator pump. I had a valve and I though to get
to a
neon manufacturer and "suck back in" some gas.

Well, the neon sign manufacturer told me that the vacuum wasn't perfect: he
will
suck more out and will refill with neon: then I'll get a "clean" and durable
plasma ball.

After he did so, I turned the ball on: I had a nice red glow all inside the
globe but NO STREAMERS, not even touching the surface. The neon pressure was 1
bar at that moment. We were shooting with a smaller TC inside the globe all the
time while refilling it, so I know that a lower pressure wasn't also better.
Only glow, no streamers.

Then I decided to let a bit of air in and neon out.

Then it started working the way it was supposed to: violet/blue streamers, with
nice red brushes at their end, dancing alone or with the drive of your hand.
Then I removed the valve and sealed the copper tube (just soldered it).

WHAT WE LEARN: you don't need low pressure, high pressure or extreme absence of
air inside your plasma globe (or whatever you are going to build) to have nice
gas discharges.

Regards

P.S. Fresh pictures of the new gas fill streamers NOT YET available on my web
site. There you can find only the "no gas" (vacuum) version of it.
http://www.saunalahti.fi/dncmrc/pglobe.htm.