how does plasma emit EM waves?

[yyh020635]

Hey guys, I'm confused with some questions and hope you guys can help me

 

1. The plasma is where electrons and nuclei of atoms are separated. If the electrons are separated from the atoms, how can the electrons of atoms be excited to get to higher orbital and then get back to the ground state and emit EM waves?

 

2. At a high enough temperature, will the elements(lets say hydrogen) emit a broad range of wavelength of EM waves like a black body? Or will it only emit certain wavelengths according to the atomic emission spectrum? why and why not?

[EdEarl]

I don't know the answer to this question, but hope someone who does know will answer. My reply will keep the thread active a while longer.

 

 

Wikipedia

The spectrum of the Sun's solar radiation is close to that of a black body with a temperature of about 5,800 K.

[John Cuthber]

Classical physics explains the emission of em radiation from a charged particle when it is accelerated. So if an electron that is traveling in a straight line then gets near the +ve charged nucleus of an atom it will be deflected from its path and the speed might also change. That's an acceleration and so em radiation will be produced.

 

At high temperatures and pressures the line spectra get broadened out to such an extent they look like a continuum.

http://en.wikipedia.org/wiki/Spectral_line#Thermal_Doppler_broadening

[MigL]

Usually plasma does not radiate ( unless accelerated as John has explained ), but there is a source of radiative energy which causes the ionization of the resulting plasma. A good example would be the Sun.

[John Cuthber]

Usually plasma does not radiate

I think you will find it does.

[Enthalpy]

The plasma is where electrons and nuclei of atoms are separated. If the electrons are separated from the atoms, how can the electrons of atoms be excited to get to higher orbital and then get back to the ground state and emit EM waves?

Transformation between two orbitals is just one possibility for an electron to radiate.

[derek w]

Photons are the force carrying particles between charged particles.

Edited January 27, 2014 by derek w

[swansont]

Usually plasma does not radiate ( unless accelerated as John has explained ),

 

Every collision involves acceleration of the charges. It's kinda hard to avoid.

[MigL]

Agreed swansont, but plasma being devoid of electrons, does not itself radiate unless accelerated ( as I originally posted ).

Edited January 28, 2014 by MigL

[Strange]

plasma being devoid of electrons

 

When does that happen?

[swansont]

Agreed swansont, but plasma being devoid of electrons, does not itself radiate unless accelerated ( as I originally posted ).

 

Regardless of the composition, there will be collisions, which means acceleration, and thus radiation.

[MigL]

I believe most of the make-up of the sun is nucleii stripped of all electrons. The early universe before it became transparent was composed of electronless nucleii. I think the critical temp is about 4000 deg.

Ok swansont, does a single nucleus of a plasma, if isolated, have a mechanism for emitting EM radiation. And I'm not considering radioactive nucleii, ridiculously high temps or annihilation.

Edited January 28, 2014 by MigL

[Strange]

I believe most of the make-up of the sun is nucleii stripped of all electrons.

 

The electrons can't just disappear (can they?) but anyway, even if there are just positive charges, they will be accelerated and generate radiation.

[imatfaal]

I believe most of the make-up of the sun is nucleii stripped of all electrons. The early universe before it became transparent was composed of electronless nucleii. I think the critical temp is about 4000 deg.

Ok swansont, does a single nucleus of a plasma, if isolated, have a mechanism for emitting EM radiation. And I'm not considering radioactive nucleii, ridiculously high temps or annihilation.

 

Yeah - but those electrons stripped off are floating around in a giant mess of nucleii, electron, and radiation; it is all hot so they are bumping into each other all the time, each bump gives of more radiation, which is absorb by the next likely candidate and so on and so on

[swansont]

 

Ok swansont, does a single nucleus of a plasma, if isolated, have a mechanism for emitting EM radiation. And I'm not considering radioactive nucleii, ridiculously high temps or annihilation.

 

No it doesn't , but that's moot in the context of this discussion. A single charged particle is not a plasma; a plasma is a gas, i.e. a macroscopic collection of charged particles. The state (solid, liquid, gas) is not defined for one particle.

[John Cuthber]

Agreed swansont, but plasma being devoid of electrons, does not itself radiate unless accelerated ( as I originally posted ).

Wrong for two reasons.

First there are electrons, whether you like it or not.

 

Secondly, it wouldn't matter, Consider a bunch of protons rattling round. When they collide they cause one another to accelerate.

They have a charge so they emit em radiation when accelerated.

There's nothing magic about electrons: as I said earlier

"Classical physics explains the emission of em radiation from a charged particle when it is accelerated."

[MigL]

I realise all that John ( and swansont ). The point I was trying to make is that there are no EM emissions from electron level hopping as no electrons are captive in atoms. A plasma is a bunch of free electrons and bare nucleii and of course they will collide and react to external fields and so emit radiation. However, a source of energy had to have been initially applied to strip the electrons from their respective nucleii, and it is greater than any emissions generated by collisions and accelerations. As in the sun !

[sheever]

Anti hydrogen fusion.

 

http://scitechdaily.com/cern-antimatter-experiment-produces-first-beam-antihydrogen/

 

http://ttf2009.ucsd.edu/research/surkogroup/positron/papers/sr6.pdf

Edited February 23, 2014 by sheever

[swansont]

Anti hydrogen fusion.

 

http://scitechdaily.com/cern-antimatter-experiment-produces-first-beam-antihydrogen/

 

http://ttf2009.ucsd.edu/research/surkogroup/positron/papers/sr6.pdf

 

And this relates to plasma emission of EM waves in what way?

[sheever]

Where do you think the radiation coming from?

[swansont]

Where do you think the radiation coming from?

The acceleration of the charges. Nothing inherently to do with fusion, much less fusion of antiprotons.

[sheever]

Not to argue but that's only what is observable. There is a little more to it.

The problem is there is 3 emergent function observable as 2.as you can see one it doesn't allow you to correct mapping.

I Ll not discuss this any further until our model will be published.

Cheers

[imatfaal]

!

Moderator Note

 

 

Not to argue but that's only what is observable. There is a little more to it.
The problem is there is 3 emergent function observable as 2.as you can see one it doesn't allow you to correct mapping.
I Ll not discuss this any further until our model will be published.
Cheers

 

Science is based on that which can be observed by independent objective experimenters. Let's call a halt to any debate which goes beyond that which can be observed and definitely stop if the argument entails a new model. As a reminder any new model should be introduced in the Speculations forum and should be discussed in that forum only.

 

Please do not respond to this mod note within the thread.

 

!

Moderator Note

 

Posts subsequent to my modtip above regarding a new theory and possible evidence for it have been split off to the trash. Do not continue to discuss non-mainstream physics in the main fora.

 

Do not respond to this modnote.