I Brownian motion of charged particles?

[Suekdccia]

TL;DR Summary

If charged particles have Brownian motion, would this motion be associated with (or produce) heat or electricity?

If we have charged particles having Brownian motion, would this motion be associated with (or produce) heat or electricity? Would it produce electromagnetic radiation (and if it would produce it, what type of radiation in the electromagnetic spectrum)? Could there be Brownian motion of charged particles in a magnetic field caused by a permanent magnet? And a static electric field?

 

[Lord Jestocost]

If no thermodynamic force exists in your system which could give rise to – so to speak – a corresponding thermodynamic displacement, "Brownian motion" would have no usable effects.

Otherwise, one speaks of "Biased Brownian motion".

 

[TeethWhitener]

Relevant:
https://en.m.wikipedia.org/wiki/Johnson–Nyquist_noise

 

[Suekdccia]

If no thermodynamic force exists in your system which could give rise to – so to speak – a corresponding thermodynamic displacement, "Brownian motion" would have no usable effects.

Otherwise, one speaks of "Biased Brownian motion".

What do you exactly mean?

 

[Vanadium 50]

You're not going to build a perpetual motion machine this way. You can only extract work out of Brownian Motion if you have a colder heat reservoir.

 

[Drakkith]

If we have charged particles having Brownian motion, would this motion be associated with (or produce) heat or electricity?

It won't produce heat or electricity, but Brownian motion is certainly the result of heat since it is ultimately thermal motion.

Would it produce electromagnetic radiation (and if it would produce it, what type of radiation in the electromagnetic spectrum)?

Yes. I suspect it closely follows thermal radiation laws, meaning that higher temperatures result in higher frequencies and higher intensities of the emitted radiation.

Could there be Brownian motion of charged particles in a magnetic field caused by a permanent magnet? And a static electric field?

Certainly. The ions inside a glass of water are charged particles that undergo Brownian motion inside the Earth's magnetic field.

 

[Lord Jestocost]

What do you exactly mean?

When charged particle in a system in contact with a single thermal bath wiggle around for a while owing to Brownian motion, what can one gain on the average if the free-energy of the system doesn’t change between its initial and final thermodynamic states?

 

[vanhees71]

One very nice use of the Langevin/Fokker-Planck/Brownian-motion approach is to understand the Landau-Pomeranchuk-Migdal effect for the motion of charged particles in a medium:

J. Knoll and D. Voskresensky, Classical and Quantum
Many-Body Description of Bremsstrahlung in Dense Matter
(Landau-Pomeranchuk-Migdal Effect), Ann. Phys. (NY) 249,
532 (1996), https://doi.org/10.1006/aphy.1996.0082
https://arxiv.org/abs/hep-ph/9510417

 

[Andy Resnick]

[snip] Could there be Brownian motion of charged particles in a magnetic field caused by a permanent magnet? And a static electric field?

It's an interesting problem, one that is beginning to be studied:

Active and passive Brownian motion of charged particles in two-dimensional plasma models, PHYSICAL REVIEW E 70, 046406 (2004)

https://math.mit.edu/~dunkel/Papers/2004DuEbTr_PRE.pdf

[abstract]:
The dynamics of charged Coulomb grains in a plasma is numerically and analytically investigated. Analogous to recent experiments, it is assumed that the grains are trapped in an external parabolic field. Our simulations are based on a Langevin model, where the grain-plasma interaction is realized by a velocitydependent friction coefficient and a velocity-independent diffusion coefficient. In addition to the ordinary case of positive (passive) friction between grains and plasma, we also discuss the effects of negative (active) friction. The latter case seems particularly interesting, since recent analytical calculations have shown that friction coefficients with negative parts may appear in some models of ion absorption by grains as well as in models of ion-grain scattering. Such negative friction may cause active Brownian motions of the grains. As our computer simulations show, the influence of negative friction leads to the formation of various stationary modes (rotations, oscillations), which, to some extent, can also be estimated analytically.