How is energy shared in plasma between particles and photons?

AI Thread Summary
In a closed system containing plasma and photons at a constant temperature T, thermal equilibrium occurs when the number of absorbed photons equals the number emitted. The total kinetic energy of the plasma is influenced by its density, while the energy density of the photons is solely dependent on temperature. Heating the plasma can either increase the number of photons or redistribute energy to enhance entropy. The equilibrium state is characterized by a specific temperature where energy absorption and emission balance out. The overall energy dynamics are determined by the system's entropy, temperature, and particle count.
Spinnor
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Suppose I had some plasma in box with walls that allowed nothing thru, photons, plasma, energy. Now heat the plasma and maintain some temperature T (ignore the difficulty in heating the plasma with the above walls, just assume you can). An approximation to this might be some small region of the sun at temperature T and nearly in equilibrium?

I assume at constant T there is an equilibrium where just as many photons are absorbed as are emitted?

How will the total kinetic energy in the plasma compare to the total energy in photons?


Thanks for any help!
 
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Spinnor said:
...

How will the total kinetic energy in the plasma compare to the total energy in photons?

Thanks for any help!

At equilibrium the kinetic energy in the plasma at given T goes as the density of the plasma while the energy density of the photons just depends on the temperature T?

Thanks for any help!
 
by restricting heat transfer between the object and the universe, the total energy inside the object is constant. heating the system can have 2 possibilities.
1 - adding more photons to the system
2 - redistributing the system such that the enthropy increases
there will be some well defined temperature T at which the total number absorbed and emitted are equal, and that's the thermal equilibrium of the system. it will depend only on the temperature of the system.
the complete description of the particles is then a function of the enrthropy, the temperature and the number of particles in the plasma.
 
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