Does r=mv/Bq hold true considering Maxwell's E.M wave theory?

AI Thread Summary
The equation r=mv/Bq is valid for a charged particle moving in a magnetic field, but it does not account for energy loss due to synchrotron radiation, which causes the electron to lose energy and spiral inward. While the radius may remain constant initially, the electron's energy loss leads to a decrease in speed and a spiral trajectory. In atomic systems, classical mechanics gives way to quantum mechanics, where fixed orbits are replaced by wave functions that describe probable locations of electrons around the nucleus. This distinction is crucial for understanding atomic behavior compared to larger-scale phenomena like cyclotrons and synchrotrons. Overall, the discussion highlights the differences between classical and quantum descriptions of electron motion in magnetic fields.
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Homework Statement

: [/B]This is a general conceptual doubt, not a numerical based doubt. We were taught that when an electron(or any charged particle) moving with uniform velocity enters a magnetic field(perpendicular to its direction of motion), then a force acts on the electron which makes it move along a circular track.
The radius is given by r=mv/Bq...(1)
Now, suddenly while studying limitations of Bohr’s theory, it stroke me that if his model was rejected based on the fact that an accelerated charged particle continuously emits energy in form of E.M waves, and so the radius of the atom should decrease and the atom will collapse which does not happen, then my question is does equation (1) hold true because here we also have an electron having acceleration...
[Note: I’m aware the cause of the centripetal acceleration is different in both cases, but I don't feel that should make a difference]

Homework Equations

: r=mv/Bq[/B]

The Attempt at a Solution

: [/B]As i mentioned above...
Please help.
Well, our currciulum does not cover modern physics in much depth, so may be I’m missing some point here...
Please help
And pardon my horrible english.
 
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Hi,

Good thinking...

(1) holds true, but yes, the electron loses energy in the form of synchrotron radiation
 
BvU said:
Hi,

Good thinking...

(1) holds true, but yes, the electron loses energy in the form of synchrotron radiation
oh...never heard of that..so does it mean the radius remains constant but the electron still loses energy?
 
The electron loses energy and slows down, so…
 
vela said:
The electron loses energy and slows down, so…
so it does form a spiral, that means everywhere in the universe they will form a spiral unless its the case of an atom, right?where we have this fixed orbitals and stuffs, right?
 
On an atomic scale you are moving into the realm of quantum mechanics, where you do not have 'fixed orbits' in the sense of 'resembling planetary orbits'.

Instead, you have a wave equation to solve and the outcome are wave functions from which features like a most probable distance to the nucleus etc. can be derived.

For large-scale phenomena google betatron, cyclotron, synchrotron, etc.
 
okay, thanks
 
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