# What happens to an electron who enters constant circular motion in a magnetic field?

If an electron enters a magnetic field and then goes into circular motion, what happens to it and its energy? I think the electron begins to emit electromagnetic radiation due to its acceleration that is perpendicular to the circular motion. This, I think I've heard it said, should result in the electrons radius of orbit getting smaller until some point. Can someone please try from the viewpoint of conservation of energy, charge and momentum etc. and explain to me what happens in this phenomenon so that I could understand it intuitively? I only have a grasp of high school physics so I would appreciate it if is possible to adjust the explanation to around my level.

EDIT: If I were to explain my current understanding of what exactly happens it would be the following (I would appreciate if you'd help me correct it in any way): The electron enters circular motion and begins "losing" energy by electromagnetic radiation due to its centripetal acceleration. This will result in its radius of circular motion (r=mv/qB) getting smaller due to it losing kinetic energy; velocity. Now this is where I am not quite sure what happens, but if I were to take an uneducated guess: does the electron just hit zero velocity and come to stop after releasing all its kinetic energy as em-radiation?

• Mar 9, 2021 at 21:01