Plasma radiation as a function of the density and temperature

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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Javier Lopez
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Plasma radiation as a function of the density and temperature

Post by Javier Lopez »

The only formula I have is the Stefan-Boltzman one:
P=5.6704e-8*T^4 (W/m2)

But it radiates too much. For an example in Iter (T=150e6), the radiation is 2.87e41 watts/m2. There is not enough power in the whole world to do that

I suppose that in magnetized plasma it must be lower.
Of course, fusor is much better in radiation because uses electrical compression instead of thermal one. I suppose plasma temperature is much lower
Patrick Lindecker
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Re: Plasma radiation as a function of the density and temperature

Post by Patrick Lindecker »

Hello,

About radiation in fusion reactors, the cyclotronic radiated power of electrons (turning on their orbits around the magnetic lines) is strong but re-absorbed by electrons themselves. The Bremsstralhung (due to collisions of electrons) is a small problem for D/T reactors but an enormous problem for future p/B11 reactors (if any).
For more information look to the §5.4.3 of this paper: http://f6cte.free.fr/Proposal_of_a_prog ... _Rev_A.pdf

>Of course, fusor is much better in radiation because uses electrical compression instead of thermal one. I suppose plasma temperature is much lower
The electrical compression is very weak and, consequently, the number of interactions is very low. On tokamaks the compression is magnetic (not "thermal"). It is the only way to efficiently compress a plasma.

Patrick Lindecker
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Richard Hull
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Re: Plasma radiation as a function of the density and temperature

Post by Richard Hull »

Indeed, the fusor's volumetric plasma temperature is very, very low! When a fusor is in the sweet spot of functionality, the entire volume is black or if a glow is visible, I can't see it. Where there is visible beaming and central collision, but much more likely, at wall impact is where the fusion gets done. The only real velocity space fusion is most likely in the beams and central star. I would imagine some fusion is done in a narrow volumetric region around the grid but that is due to more rare probabilistic Quantum Tunneling. These rare events contribute for sure as we have volume in the spherical device and near sphericals like crosses and cubes.

While all of the above is contributing to real fusion that can do things at the amateur experimental level, in the best of these different fusor and fusor like devices, IECF is not and will never produce any real power or even approach break even. Remember, that if you ever get just 5 watts of fusion energy out of a fusor, you would be killed!

A pseudo-neutral plasma emits light due to recombination. We see this in the big boy's machines in the bright donuts when they run for those tiny instances they can. They pump real kilo to mega amps into the system that creates the donuts to keep them highly thermal and contained via magnetic confinement. Takes joules to make joules.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Javier Lopez
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Re: Plasma radiation as a function of the density and temperature

Post by Javier Lopez »

Thanks both.

I will take in account the cyclotron radiation: P=4e-17*ne*B^2*E (kev)
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Javier Lopez
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Re: Plasma radiation as a function of the density and temperature

Post by Javier Lopez »

Well, I have a problem with the formula, because I obtained a different value, as can be seen here, I would be happy if somebody checks it:


Image

ne is the number of electrons (or ions)
B is the magnetic fields in teslas
P=output power (watts)
I suppose the electron speed is perpendicular to the magnetic field, otherwise, it would hit the plasma reactor wall

NOTE: I introduced the latex formula using an external link to www.codecogs.com
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