# Electromagnetism and plasma physics questions



## NerdyCavegirl (Apr 13, 2016)

So this idea comes from the tokamak, which I seem to be having trouble finding information on, and I'm not too sure how accurate Wikipedia is. I also lack the math skills to process much of this information; I'm a physics enthusiast, not a physics expert. So here goes....1: What is the operating temperature of the plasma in a tokamak? Wiki says over 100 million degrees Celsius. 2: How powerful is the electromagnetic field needed to contain this plasma? Wiki says 15 mega amperes. 3: What exactly is the relationship between amperes, volts, watts, and joules? 4: I know some flames are plasmas, and that the ions are what make a plasma electromagnetically conductive, so could any strength current be used to contain a flame? 5: I read that the fuel in a tokamak may be heated to operating temperature by microwave radiation, so why exactly is this frequency prefered and how does this process work? Any help would be greatly appreciated!


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## Vaporo (Apr 13, 2016)

1. Google search says that 150 million Kelvin is roughly the operating temperature of a fusion reactor.

2. Probably depends on the reactor.

3. Amperes is not a measure of magnetic field strength. Magnetic field strength would be measured in Tesla under the SI system, so your 150 million ampere measurement is a measure of the number of electrons that need to flow through the wire every second in order to maintain the reactor's magnetic field (9.3615*10^25 electrons per second). A volt is kind of like amount of force pushing the electricity through the wire. High voltage is what makes electricity jump gaps like lightning, and higher voltage means that electricity can be transmitted longer distances By multiplying voltage and amperage together you get wattage, which is a measure of the rate at which power is flowing through the wire. One watt maintained for one second means one Joule of energy has been flowed through the wire (consequently, one watt-hour equals 3600 Joules).

Amperage and Voltage can be interchanged be various electrical components. If I have a normal household current of 12 volts and 10 amps (120 watts) I can create a current of 12 amps and 10 volts, or 5 amps and 24 volts, or any two arbitrary numbers that multiply to 120.

4. Only the hottest flames can be considered plasma. Most flame is just smoke that is still hot and burning as it leaves the fuel source.

5. I suppose that it's because microwaves lie in some kind of electromagnetic sweet spot where the most energy is absorbed by the material as opposed to passing through or bouncing off. I'm not sure.

Why, exactly, do you need this information? I don't think that most readers will care about the exact specifications of your fusion reactor.


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## NerdyCavegirl (Apr 14, 2016)

Thanks for the relevant and well-organized info. It isn't for a fusion reactor per se, but for another system operating in a similar matter. And because I'm a nitpicky bitch, I like to have a sound foundation to avoid logical inconsistencies, and the characters care. At least some do, some couldn't care less either. What exactly do you mean by "hottest flame"? I'm assuming not a candle.


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## CupofJoe (Apr 14, 2016)

I'm sure I was told that Plasma was a state of matter beyond Gas...
Solid, Liquid, Gas, Plasma.

As for the hottest flame? According to Wikipedia...


> Dicyanoacetylene, a compound of carbon and nitrogen with chemical formula C4N2 burns in oxygen with a bright blue-white flame at a temperature of 5260 K (4986.85 Â°C, 9008.33 Â°F), and at up to 6000 K in ozone.[7] This high flame temperature is partially due to the absence of hydrogen in the fuel (dicyanoacetylene is not a hydrocarbon) thus there is no water among the combustion products.


 - Wikipedia


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## NerdyCavegirl (Apr 15, 2016)

Yep, tis an ionized gas, the most abundant and probably the strangest state of matter in the known universe. Has a special place in my heart. And I imagine that hella hot flame (which I'd love to see a picture of but can only find colder average blowtorch flames on Google) would be one of those considered plasma, though I figure there's also a lower temperature limit at which gases are officially ionized enough.


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## K.S. Crooks (Apr 17, 2016)

Ampere is the flow of electrons (current) in #/second, Voltage is the amount of energy/group of electrons (in joules), a joule can be thought of in a couple of ways- the amount of energy to raise 1 gram of water a quarter degree Celsius or Kelvin or the amount of energy to lift 100 gram 1 metre. Watt is the voltage x current. To see real plasma in action check out NASA - Sun-Earth Day - Technology Through Time - #53: Solar Prominences


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## kennyc (Apr 17, 2016)

Vaporo said:


> ....
> 
> Why, exactly, do you need this information? I don't think that most readers will care about the exact specifications of your fusion reactor.



This. Fiction is about creating the dream, inviting the willing reader in.


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## NerdyCavegirl (Apr 17, 2016)

kennyc- I done answered that, no point in stating it again. See above a few posts. As I write recreationally, not for anyone to read but those I choose, I could care less what any readers want. For me, fiction is a pleasant exercise of my mind. I wouldn't ask these damn questions if  I had any doubts about their relevance.


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