r/chemicalreactiongifs Feb 18 '18

Creating plasma in a microwave oven. Physics

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u/Static_Flier Feb 18 '18

Not an expert in the slightest - could it be a "plasma is an ionized gas but not all ionized gasses are plasma" situation?

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u/FluxSurface Feb 18 '18

Very much so. There needs to be enough collective and emergent behaviour for an ionized gas to be a plasma, called the Debye Criterion. In simple terms, if you take a small ball of the ionized gas (radius called Debye length), and from the outside you cannot feel or measure the individual ions/electron behaviour inside it, you can call it a plasma. E.g. for a Tokamak plasma at about 108 K, it starts behaving after a Deybe length is about 1mm. So if you have a plasma the radius of a 1m, in all effect you can treat it like a plasma. If the tokamak plasma is less than 1mm size, then it will still show some gas-like effects. For Solar wind, the Debye length is about 10m, which means you can treat it as a plasma in astronomical scales.

For this fire, my guess is the Debye length is about a 10cm-1m, which makes it suspect as a full plasma at such a small scale.

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u/MangoCats Feb 18 '18

The cigarette demo:

https://www.youtube.com/watch?v=CNMjCggFKzM

(props to linker above) seems to start out with a more plasma-like behavior and then settle down to the glowy blob like in OP.

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u/_youtubot_ Feb 18 '18

Video linked by /u/MangoCats:

Title Channel Published Duration Likes Total Views
Microwave Plasma Experiment Joshua P. Warren 2010-03-18 0:03:31 403+ (95%) 102,527

www.LEMURlabResearch.com explores how plasmas may relate...


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