Accelerating electrons giving off radiation

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Discussion Overview

The discussion centers on the radiation emitted by electrons in a superconducting ring due to their acceleration. Participants explore the implications of this radiation on the half-life of a supercurrent, considering both theoretical and practical aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that since electrons in a superconducting ring are accelerating, they should emit electromagnetic radiation and inquires about estimating the half-life of a supercurrent based on the ring's radius.
  • Another participant proposes using the Larmor formula for estimating radiation, noting its applicability in non-relativistic cases and suggesting potential generalization for relativistic scenarios.
  • There is a question raised about the speed of electrons in superconductors, with one participant asserting they are moving slowly, while another counters that their speed can vary significantly depending on the situation.
  • One participant mentions that the radiation is proportional to the square of the acceleration, indicating a relationship between acceleration and emitted radiation.
  • A participant questions whether the radiation formula applies only to isolated charges, referencing external sources that discuss cyclotron radiation and its implications for multiple charges.
  • Further clarification is provided that while the Larmor formula may not apply well to normal conductors, it should be suitable for superconductors.

Areas of Agreement / Disagreement

Participants express differing views on the speed of electrons in superconductors and the applicability of the Larmor formula, indicating that multiple competing perspectives remain unresolved.

Contextual Notes

There are limitations regarding the assumptions made about the speed of electrons and the conditions under which the Larmor formula is applicable. The discussion also reflects uncertainty about the behavior of multiple charges in relation to radiation emission.

granpa
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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.
 
Last edited:
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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.
 
the electrons in the superconductor are moving slowly arent they?
 
basically its proportianal to a2
a=acceleration
 
granpa said:
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.

granpa said:
basically its proportianal to a2
a=acceleration
Absolutely, and that's generally the case (at least for non-relativistic situations).

granpa said:
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.
 

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