Interesting Links Between Faraday's EM Induction and EPR

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Discussion Overview

The discussion explores the relationship between Faraday's law of electromagnetic induction and electron spin resonance (EPR), particularly focusing on the implications of a moving magnet inducing an alternating emf in a copper rod. Participants consider the conditions under which the induced voltage might exceed predictions made by Faraday's law, especially when accounting for electron behavior in the context of resonance frequencies.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant proposes that if a magnet moves quickly enough to match the electron spin resonance frequency, it could lead to increased voltage production beyond Faraday's predictions, given specific conditions regarding the copper rod's length.
  • Another participant questions whether copper electrons are free, suggesting that if they are not, their gyromagnetic ratio may differ from that of free electrons, but the overall process remains unchanged.
  • A participant discusses the need for synchronization of the magnetic field transition along the length of the dipole, raising concerns about the feasibility of achieving the required speed for the transition.
  • Another participant suggests that the engineering constraints should not overshadow the conceptual discussion, proposing an air-cored three-phase coil system that could operate at MHz frequencies to induce emf in conductors.
  • One participant emphasizes the importance of physical feasibility in the proposed topology, indicating a potential misunderstanding of the magnetic field configurations involved.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of the proposed concepts, with some focusing on the theoretical implications while others emphasize engineering constraints. No consensus is reached on the practicality of the ideas discussed.

Contextual Notes

Participants highlight limitations related to the assumptions about electron behavior in copper, the synchronization of magnetic fields, and the physical arrangement of the proposed systems. These aspects remain unresolved within the discussion.

Narayanan KR
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TL;DR
If observed carefully, one can find similarities between a conventional generator and a EPR (electron paramagnetic resonance) machine as described below.
epr1.jpg

Imagine a magnet moving up and down so that its flux 'B' cuts the copper rod to produce an alternating emf, suppose if the movement is fast enough such that its frequency equals to the electron spin resonance frequency given by F = B x 2.8 Mhz per gauss, neglecting skin effect, more copper electrons will spin up and then spin down loosing their energy as EM radiation (as happens in Electron Paramagnetic Resonance), in that case if the length of the rod is chosen to match the wavelength of the emitted energy, then will such a condition lead to more voltage to be produced than what the faraday's law will predict ?
 
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Are copper electrons free?
 
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Baluncore said:
Are copper electrons free?
if they are not free then they might have a gyromagnetic ratio slightly different from that of a free electron, but rest of the process remains the same.
 
Narayanan KR said:
... suppose if the movement is fast enough such that its frequency equals to the electron spin resonance frequency given by F = B x 2.8 Mhz per gauss, ...
Narayanan KR said:
... in that case if the length of the rod is chosen to match the wavelength of the emitted energy, ...
That would make the λ/2 dipole resonant at one particular frequency. The B field would need to be level along the entire excited dipole.

How will you synchronise the transition from Bgreat to Bfixed, over the length of the dipole. That step edge will need to be very fast, not something a moving magnet can do.

The dipole is really a resonant folded transmission line of length λ. The step will need to propagate along the dipole from one end to the other in order to synchronise the individual electron relaxation into a coherent wave.

So what if you excited only a very short section of the dipole. Would the stable B field lines need to encircle the dipole? How would the switched field that drives the relaxation be arranged?
 
Baluncore said:
That step edge will need to be very fast, not something a moving magnet can do.
why are you worried about the engineering and design constrains instead of answering for the concept alone ? .Imagine an air cored 3 phase coil system that produces rotatory magnetic field except that the frequency is in Mhz range, now you can cut any other conductor by placing it inside the coils at ultra fast rates, the copper rod need not be half wave length but an multiple of half wave length.
 
Narayanan KR said:
why are you worried about the engineering and design constrains instead of answering for the concept alone ?
This the Electrical Engineering forum. NOT the Classical Physics forum.

The topology must be physically possible. I think you have your fields crossed.
 

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