True or not , a piece of metal in a microwave oven will create an electric discharge.

[William Gaatjes]

I was reading about how this can happen. What i understand about it, is that there happens local ionization especially on point shaped parts of the surface of a piece of metal. Is this correct ?
Just a question, i suspect it is possible to ionize a piece of metal as well with x rays. Is this true ?

Just for the fun, i was thinking of starting the ATHT direct conversion reactor thread. :awe:
Please join in.

 

[William Gaatjes]

I had this idea about how that direct conversion should work from the focused fusion thread. Direct conversion meaning no heat to steam to generator to electricity, but particles to useful electricity.
Suppose that you have two electrodes that are ionized. And that between these two electrodes a high power discharge takes place. It is nothing net energy conversion, it is just for the idea.
Between these electrodes there is a (discharge)space. around this space i place a coil so that i create a transformer with 1 winding(the primary "coil") being the space between the electrodes and another secondary coil around it.
If i would have a sufficient discharge between the electrodes with a high current density, would i not induce a strong pulsed magnetic field and as such induce a pulsed current flow in the secondary coil ? If that works, it is not much different than switch mode power supply techniques to get dc current out and convert that with electronics back to AC.
Now if instead using two electrodes that i discharge, i would use a charged particle beam consisting of electrons from a zpinch setup.
Would that function ?

 

[who?]

I can't watch them where I am right now but I believe that the you tube videos of incandescent light bulbs being microwaved show them glowing.

 

[Red Squirrel]

Yeah it will spark up and stuff, that's why you can't put anything metal in the microwave. Lightbulbs will light up too. It's safe to try it for a few seconds if you want to see, it's kind of cool.

Foil paper in the microwave is quite impressive too. If you're going to experiment with stuff I would suggest buying a cheap microwave to do it with though. Read up on proper safety as some stuff is actually extremely dangerous due to the kind of radiation it can produce.

Though, here's a messed up one, my mom bought a new over the range microwave, and it comes with a METAL grille that you can put inside if you want to cook two things at once on top of each other. There's a warning making sure the grill does not touch the wall of the microwave (it has little plastic legs) so that makes me wonder, perhaps ungrounded metal stuff wont actually discharge. Only stuff that's actually grounded maybe?

 

[William Gaatjes]

I can't watch them where I am right now but I believe that the you tube videos of incandescent light bulbs being microwaved show them glowing.

Yeah it will spark up and stuff, that's why you can't put anything metal in the microwave. Lightbulbs will light up too. It's safe to try it for a few seconds if you want to see, it's kind of cool.

Foil paper in the microwave is quite impressive too. If you're going to experiment with stuff I would suggest buying a cheap microwave to do it with though. Read up on proper safety as some stuff is actually extremely dangerous due to the kind of radiation it can produce.

Though, here's a messed up one, my mom bought a new over the range microwave, and it comes with a METAL grille that you can put inside if you want to cook two things at once on top of each other. There's a warning making sure the grill does not touch the wall of the microwave (it has little plastic legs) so that makes me wonder, perhaps ungrounded metal stuff wont actually discharge. Only stuff that's actually grounded maybe?

That is interesting that an incandescent light bulb also glows. Is it the inert gas inside the bulb or is it the filament that glows ? If it is the filament, that is interesting. Must be not only because it is metal (lot's of "free" electrons moving around in metal. But it must also be the wounded shape of the filament then. The ionized electrons ionize the gas in the lamp by releasing em radiation when going to a lower energy state or just produce em radiation in the visual range.
I have an old microwave oven laying around in the basement.
Perhaps i should setup an experiment. I have to check if i have mains power in my basement. I read that the microwave em radiation ionizes the free electrons moving around in a metal. especially at pointy shapes, the electrical field is strongest (i guess there all the electrons are drawn too) and the voltage difference highest with respect to the metal case of the microwave oven.

I remember that air ionizers also work best when there are lot's of pointy tips. Very interesting to build up a local charge by using em radiation.

 

[angminas]

When I was a kid, we put a G.I. Joe in the microwave. Its metal joint fasteners started sparking blue, and we shut it off after a few seconds. So I'd think that would eliminate the ungrounded thing.

 

[William Gaatjes]

When I was a kid, we put a G.I. Joe in the microwave. Its metal joint fasteners started sparking blue, and we shut it off after a few seconds. So I'd think that would eliminate the ungrounded thing.

You are right, ionizing happens best at pointy tips. But to get a discharge, there must be an electrical field between that tip and something else like for example the metal case. The air inside the microwave oven becomes ionized around the pointy tip and when the electrical field becomes strong enough to surpass the dielectric strength of air, the air breaks down and starts conducting for a short moment.

 

[dkozloski]

Split a grape not quite in half and spread it on a paper plate keeping a small section of skin intact and put it in the oven. Turn on the microwave for a plasma light show.