Ball lightning in a Microwave Oven.

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Linda Haile
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Ball lightning in a Microwave Oven.

Post by Linda Haile » Wed Feb 10, 2010 6:34 pm

I came accross this article while searching for plasma/ion sources.

http://jlnlabs.online.fr/plasma/gmrtst/

I'm not sure it would be much use for fusoring, but it looks pretty spectacular. I know there are some here who are interested in ball lightning.

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Chris Bradley
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Re: Ball lightning in a Microwave Oven.

Post by Chris Bradley » Wed Feb 10, 2010 6:52 pm

It's a plasma, and it's ball shaped. Nothing more to say about it. It isn't 'ball lightning' as other sources mean for ball lightning.

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Doug Coulter
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Re: Ball lightning in a Microwave Oven.

Post by Doug Coulter » Wed Feb 10, 2010 7:10 pm

This is the same thing I'm doing much smaller and much more efficiently here:

http://www.coultersmithing.com/AuxCP/uWaveIon.html

And here:

viewtopic.php?f=12&t=5022#p32330

A big enough E field will ionize gas, no surprise there. The trick is doing it without so much power and without contaminating the plasma with other things that get evaporated.
Why guess when you can know? Measure!

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Carl Willis
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Re: Ball lightning in a Microwave Oven.

Post by Carl Willis » Wed Feb 10, 2010 7:33 pm

viewtopic.php?f=14&t=6527#p42210

Microwave oven ball lightning is an electrodeless arc, established in the oven cavity's fields typically by a flame, a bisected grape, or by purpose-built metal resonators. It's been a perennial diversion for high-voltage hobby enthusiasts since time immemorial, and as the thread above shows, has gotten attention on this forum from time to time.

It is fun to see how long the arc lasts. Typically it is extinguished when it rises by its own heat to the oven ceiling. Sometimes it will persist for large fractions of a minute though, swimming around on the ceiling and burning up the paint. For best results the oven mode stirrer, ventilation fan, and light bulb should be disabled and the oven should be turned to sit on its short side, giving the arc more room to climb.

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Brett
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Re: Ball lightning in a Microwave Oven.

Post by Brett » Thu Feb 11, 2010 1:44 am

I do it occasionally to wow the kids; Three glasses, two upright, the third inverted sitting on their edges to hold the plasma, and a tea candle to initiate. Pyrex glasses, of course. Sure does a good job of cleaning glass, I'll tell you that.

Chris Trent
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Re: Ball lightning in a Microwave Oven.

Post by Chris Trent » Sun Feb 14, 2010 3:43 am

Ordinary light bulbs do quite well for this also, but be careful not to give your kids too many ideas.

Brett
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Re: Ball lightning in a Microwave Oven.

Post by Brett » Mon Feb 15, 2010 2:19 am

A "techie" has been defined as somebody who'll try anything, *in somebody else's home*. In that spirit, I do this to wow other people's kids.

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Chris Bradley
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Re: Ball lightning in a Microwave Oven.

Post by Chris Bradley » Mon Feb 15, 2010 5:46 pm

I can't say I find this thread an interesting topic, but the phrasing of your post prompted me to think of what a wilderness survival instructor once told us: "If your hands are really cold and you need to warm them up, put them on your neck or your inner thighs. If your hands are really *really* cold, put them on someone elses."

Starfire
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Re: Ball lightning in a Microwave Oven.

Post by Starfire » Tue Feb 16, 2010 1:52 pm

Is that an invitation ? Chris ?

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Doug Coulter
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Re: Ball lightning in a Microwave Oven.

Post by Doug Coulter » Wed Feb 17, 2010 1:37 am

I can't believe that no one has mentioned using a CD as a test object.
Quite a nice demo. We did this all the time with those that AOL used to flood the planet with -- you can only use so many drink coasters or pistol targets that already have one hole (which makes for excuses on the range -- I didn't miss, I shot through the existing hole, etc).
It does make a mess though, so keep the duration short to just see the lightning. Haven't tried it with a burnable one, I suspect that would be completely different than the thin aluminum on the pressed guys.
Why guess when you can know? Measure!

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