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W. Beaty 1998

(Originally discovered by Ed Harris, 1995, 'usa-tesla' discussion group)

[fishbowl of argon with Tesla coil dipped 

scroll down          Also see: Building DIY Plasma Globes

After hearing about a rumor that "Eye of the Storm" plasma spheres use high pressure helium, Ed Harris experimented with tesla coils and nobel gases. The rumor is true! A box or balloon full of pure helium acts like a "plasma sphere" but at ambient pressure. Or use pure welder's argon for immensely long snakelike discharges! - billb

first test video
MPEG 1.0M, bill b. 9/2005

Side view
MPEG 900K, bill b. 9/2005

MPEG 4.3M, bill b. 9/2005

In the above videos, I used a Handheld Tesla Coil, "violet ray" style, $100 - $200


People in the past have used Tesla coils for powering plasma globes since they require a high-voltage high-frequency power supply. Tesla himself experimented with these globes in the form of his carbon "button" bulbs.

If you can build an argon-filled discharge chamber, it allows you to get many times the arc length of a standard air-discharge tesla coil.

In some high pressure plasma experiments, people have in the past sometimes added helium gas to raise the working pressure of a plasma discharge -even up to and beyond 15psi.

I have tested this idea recently with a homemade plasma sphere run from a small 15kHz flyback supply. I can obtain 15psi discharges in helium with some small partial pressure of air(or other gas) with rather small input from the flyback (est~5Kv).

So yes! You can run a plasma sphere at atmospheric pressure with helium + small dopant gas.


Now if I can only find some reasonably non-toxic gas which produces nice colors!

-Ed Harris

Well- some guy remarked previously about using a plastic bag or the like as a atmospheric pressure plasma sphere. So I accepted the challenge :)

I was able to make a plasma sphere using a rubber balloon which was very well purged of air (air partial pressure approximately 1/1000 atmospheric pressure) and filled with helium. Powered by a 10kV flyback circuit, the arcs inside the balloon could be seen to extend from the central electrode all the way out to the rubber (about 5 inches).

Hope some others try this It's rather neat!

-Ed Harris

Date: Sat, 12 Aug 1995 11:51:29 -0700 (PDT)
From: William Beaty <>
To: list physics teaching
Subject: Rubber ballon plasma sphere

Wow, at one atmosphere!!! How about sealing a rubber glove to a largish balloon, stick a hand inside, and let plasma play on your fingers? Got a good camera? Should be good for an Omni magazine cover!

And how about an entire room with a Helium or Argon atmosphere? Such things must exist somewhere. If a *glassless* plasma globe unit was taken into one, wouldn't the plasma filaments extend right out into the air? And what would happen to colors and plasma-filament structure when small bags of various 1-atm gases were released in such a room? Or if a handheld unit was moved through various gas layers in a glovebox chamber?

Or hold your breath, go inside, touch a larger tesla coil terminal, and see if humans can serve as plasma globe electrodes.

If the leads to a neon-sign transformer were connected across a large volume of Helium, would a "beam" of red plasma leap between them? If so, what would happen if you poked at the plasma beam with a glass rod, or tried to cut it with a glass sheet? Could a plasma-globe power supply and a UV laser be used to create a *real* Star-Wars movie lightsaber effect inside a large He-filled chamber? Mind boggling.

The physics demonstrators sure are going to have fun with this one!

- Bill Beaty,


Shoot arcs from fingertips!
MPEG 1.5M bill b. 9/2005

MORE STUFF from billb

Ed Harris discovered that pure Argon works even better than Helium, giving bright white snakelike discharges like those seen in various Plasma Globes.

I experimented with this and found that Nitrogen contamination (air) wrecks the effect. Therefor, if you try an Argon-Balloon Plasma Globe, you need to flush all the air out first. Do this by squeezing out the balloon, filling it part way with Argon, allowing the argon to all 'squeal' out, then fill the balloon with Argon all the way. The argon in the balloon can generate long white discharges, but if you wait for a few hours, the nitrogen will get in through the rubber walls and spoil the effect.

If a metal rod or coathanger wire is pushed up into the balloon and the balloon neck is sealed with cable ties, you've got yourself a quick and dirty non-glass plasma globe! It only lasts a few hours though, before air diffuses through the rubber and poisons the effect again.

I messed with the argon gas in a large plexiglas cube. Argon is a bit heavier than air. If you fill a box slowly with argon from the bottom, and provide an exit hole at the top, the box will fill up slowly, and you can obtain long, snakelike discharges near the bottom of the box as the slightly-heavy argon drives the air upwards. The argon hose MUST have a diffuser such as an aquarium air-stone, or just tie a piece of paper towel around the end of the hose. The same tesla coil terminal that only gives inch-long discharges in air will give foot-long discharges in Argon. Pretty cool to move the tesla coil terminal wire to different places in the box and watch the discharge grow from a dim, purple air corona to blazing white argon snakes many inches long.

What would happen if we had a box with layers of helium, neon, argon, etc. inside? As the electrode was pushed through various layers, the plasma filaments would take on totally different color and length.

Trap a layer of argon between nitrogen above, and something heavy (maybe CO2 or sulfur hexaflouride) below. Then a wire could connect to that argon layer, and a blazing disk of plasma would flow out into the narrow argon layer. (or does SF4 gas make long plasma streamers too?)

If you build a plexiglas box, be aware that the fumes from plexiglas solvent or from silicone caulk will pollute your argon. Let your box dry for a couple of days before working with the argon, maybe attach a tiny fan to holes in the box to drive out the outgassing glue fumes.

Oh, the industrial grade argon obtainable in welding tanks (about 70$ recharge) works just great. An Argon+CO2 mix didn't work, CO2 apparently also poisons the long-sparks effect.

Plasma Globe links, magazine articles, etc.

I used a Handheld Tesla Coil, $130, #HS-10 from Edu. Inno. catalog, SEE PAGE 42

Date: Tue, 16 Jun 1998 23:26:05
From: mycroft42
Subject: Argon-based electoplasma effects.

Hi, found your website today, love the mad science hoaxes. I had a question about a common source of Argon that might produce some interesting facts.. There are thermally insultaing windows available that contain an inner atmosphere of argon. Has anyone experimented with these windows to see what effects can be made? (has anyone thought of modifying these windows _in a house_ to that each could be "tur ned on"? frankly it sounds like a neat form of environmental art just waiting to be tapped)

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