[Prev][Next][Index][Thread]
NEON- Plasma Balls
Hey neon folks,
Here's a change of topic from all the code and rule stuff.
I experimented with these several years ago on a minor scale - limited
success. I built the supply described in the now defunct RE magazine in
1990. My "balls" were empty rare gas bottles. I had problems getting a
steady discharge of streamers from the center electrode. When I put my
hand accross it, there were some, but otherwise just a steady dim
glow... and lots of ozone <g>
Okay, now I'm in possesion of Scientific Systems top-O-the-line HF
supply (PV-150), glass to metal seals, ceramic kiln I've used for small
annealing, and other related stuff. I'm considering an 18" borosilicate
round-bottom flask blank. This is the largest size I can fit in the
kiln.
I'm planning: 1) bake out completed ball unit under vacuum (say at 300C
or so), 2) bomb the "electrode" (really just try to outgas it w/some
current) via a side tubulation on the neck with a second 'trode (a
Eurocom borosilicate). 3) of couse, fill with gas.
Here my uncertainty begins. Anyone know a good starting point for fill
pressure? I've heard 3 torr. My earlier experiments with pure neon
seemed to suggest a higher (8-9) to generate plasma. Anything to be
gained by splurging for some helium, krypton, etc.? Mercury? I almost
seemed to have better luck with "air" than rare gas in creating the
proper effect.
I can (I think) fit approx. a 1" ball (electrode) thru the neck. Is
this large enough? Many commercial units I've seen have quite large
balls inside. (These also appear to be epoxied together, so I'm sure
their life is short). I have a large stainless ball-bearing, but it's
heavy. I was thinking of scrounging thru a pot&pan store for some sort
of small, round stainless (and hollow) doo dad.
Anyone else experimented along these lines?
-John
Follow-Ups: