Accelerating electrons giving off radiation

[granpa]

Since the electrons flowing around a superconducting ring are accelerating they should give off electromagnetic radiation.
Based on this, is there any easy way to estimate the half-life of a supercurrent given the radius of the ring?

even a back of the envelope order of magnitude kind of thing is fine.

 

[zhermes]

I think the Larmor formula is what you're looking for (http://en.wikipedia.org/wiki/Larmor_formula). Note, however, it only applies to the non-relativistic case. I think the article shows a basic derivation, you might be able to generalize to the relativistic case; otherwise you'd have to work from maxwell's equations.

 

[granpa]

the electrons in the superconductor are moving slowly arent they?

 

[granpa]

basically its proportianal to a²
a=acceleration

 

[granpa]

The only question I have is whether this only applies to isolated charges.

this
http://en.wikipedia.org/wiki/Cyclotron_radiation
doesnt seem to suggest that it makes any difference how many charges are involved

but then again
https://www.physicsforums.com/showpost.php?p=1287217&postcount=8

 

[zhermes]

the electrons in the superconductor are moving slowly arent they?

It depends on the case; they can be moving essentially arbitrarily fast... depends on the situation.

basically its proportianal to a²
a=acceleration

Absolutely, and that's generally the case (at least for non-relativistic situations).

The only question I have is whether this only applies to isolated charges.

It wouldn't apply well to a normal conductor, but for a superconductor it should be fine.