I copied this from a web page somewhere. I wish I had the guy's name so I could give him credit, but for now he'll have to be anonymous. The real problem you will have initially is getting a high-voltage power supply. Although TVs use high voltage, just unhooking the lead stuck on the back of your TV ray-tube won't work (I've tried). McMaster Carr has high-voltage power supplies, as do other catalog companies. I recommend buying a used neon light transformer from on-line auctions or classifieds.
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Most people have all these tools, with the exception of a pump. So, this is not so difficult. I highly recommend purchasing a quality drill bit that will give a clean and accurate 3/4" cut in plastic. Use lubricant while cutting!
Materials:
High voltage power supply, pulsed (see below - make your own, of course!)
Glass globe
1/4" acrylic sheet, preferably cast OR 3/16" polycarbonate sheet (preferred)
3/4"OD X 1/5"ID tube, of same material as your sheet above
Ball bearing, I prefer 1 1/4" diameter, but you can choose your size (this is just a steel
ball)
2-part epoxy is preferred, but RTV silicone will work
Methylene Chloride is a solvent cement that is wise to search for and acquire
Tygon tubing, 1/8" ID
Helium, or some other gas (even air works great!)
The glass globe is easy to get. I use a 7 1/2" diameter clear (it actually has a slight smoke tint) globe used for lighting fixtures. You can get them from any store with a big selection of lighting fixtures. I bought mine at a local Menard's store. For plastic sheet, I recommend polycarbonate because of it's strength. This device is something you might play with quite a bit, and you don't want acrylic cracking when you are in the middle of something interesting. Polycabonate can not crack. It costs more, but is well worth it. This is of particular concern when cutting the hole for the center electrode. The sheet is for mounting the globe, and epoxy is recommended for fastening (save this for last!). The ball bearing is actually just a steel ball, used for ball bearings. They can be purchased individually through McMaster Carr (see below). Methylene Chloride can be purchased through chemical supply companies. The tubing is needed to hold the ball bearing in the center of the globe. Tygon tubing is a clear plastic flexible tubing. A hole should be drilled in the plastic plate for this tubing (use epoxy to bond, for best results). It is needed to evacuate and purge the globe. This is a material that a local scientific supply store should carry. It is also available, of course, through McMaster. I will have pictures of my globe here in a couple of weeks.
A variation on this is to experiment with an insulating coating on the ball bearing. This coating will change the characteristics of your globe somewhat.
� Many of these supplies are found in the McMaster Carr supply catalog.�My experience with this company has been first rate. They have just about EVERYTHING! Prices may be slightly higher than your local stores, but it is worth it when you consider that most of what they carry is difficult to find elsewhere, unless you are specialist. Some of their prices are even quite a bit lower than you would find elsewhere. The catalog is a must-have for a serious tinkerer. It is as standard on a mechanical engineers desk as many textbooks. It is hard to get one, though.