Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx>
Ed:
Sorry, I'm a little late on this. Got behind on "list" e-mails.
I have found -20 to -22 " Hg to give the best effect.
Mixture target was 90% Neon, 5% Xenon, 5% Krypton.
See our Globes at www.TeslaBoys.com
Our gas control for filling is rudimentary.
After building two blue balls I thought I had the method down to a
science.
The 3rd and 4th turned out green, and the 5th blue again.
All were "loaded" in what I thought was an identical method.
Obviously, the color is very sensitive to the ratio of Xenon/Krypton.
This method gives a pink color all around the periphery of the ball(from
the Neon).
The streamers turned out blue or green(from the Krypton/Xenon mix?).
In both cases placing your hand on the ball gives a blue/white streamer
clearly caused by the Xenon.
Used an air conditioning compressor as a vacuum pump and a manifold with
a bunch of valves.
Pumped down to full vaccuum then admitted a fixed volume of gas at a
fixed pressure based on PV=nRT to reach the goals.
Purchased gas in 10 liter bottles(small propane torch size) from
www.specgasinc.com
Neon $30, Krypton $45, Xenon $60. Of course, shipping to boot. Make
sure to ask for a valve(CGA-600). It adapts the std propane type
connection to 1/4" npt and has a built in needle valve.
Note: I did the pressure testing with Argon and found the best result
that way and used that as my target for the other gases.
I have not tried a lot of gas combinations because I got lucky early in
my trials. There may be other better combinations.
Mark
-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Sunday, October 09, 2005 3:11 PM
To: tesla@xxxxxxxxxx
Subject: Re: home grown plasma globe
Original poster: Ed Phillips <evp@xxxxxxxxxxx>
"gas mix and pressure is very important as to what kind of display you
will get, a (very)low pressure system will give you more wispy streamers
as to where a higher pressure( still near vacuum) will give you more
lightning bolt effects. "
Does anyone have any good "recipes" on the topic to share with
us? I'd be very much interested.
Ed