Oscillating charge, larmor power dissipation

In summary, we discussed the equation of motion for a z-polarized incident EM wave hitting a small charge bounded to a massive charge with spring constant k0 and frequency ω. We also found the time averaged total power dissipated and the classical scattering cross section σ (thomson). Finally, we determined the value of E0 that makes the magnetic forces non-negligible, correcting an earlier mistake that was made in the dimensional analysis.
  • #1
unscientific
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Homework Statement



A z-polarized incident EM waves hits a small charge (-q) bounded to a massive charge (+q) with spring constant k0 and frequency ω.

(a) Write down the equation of motion

(b)Find time averaged total power dissipated.

(c) Find classical scattering cross section σ (thomson)

(d) Find value of E0 that makes magnetic forces non-negligible.

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The Attempt at a Solution



Part (a) and (b)
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Part(c)
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Part (d)
Because velocity of particle is slow, so magnetic force on it is low, giving it a small magnetic displacement compared to the electric displacement.

I related equated magnetic displacement to electric displacement to find a value of E0.

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  • #2
I'm not sure if part (d) is right.
 
  • #3
bumpp
 
  • #4
bumpp
 
  • #5
As far as I can tell:

(a) OK
(b) The mass occurring in the fraction part of your answer should be replace by some other quantity. Otherwise, OK.
(c) Fixing (b) will affect the answer for (c).
(d) OK

Note, you should make a dimensional analysis of your results. This would help you see that your answers for (b) and (c) can't be correct.
 
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  • #6
TSny said:
As far as I can tell:

(a) OK
(b) The mass occurring in the fraction part of your answer should be replace by some other quantity. Otherwise, OK.
(c) Fixing (b) will affect the answer for (c).
(d) OK

Note, you should make a dimensional analysis of your results. This would help you see that your answers for (b) and (c) can't be correct.

I mistakenly thought p = momentum, but it should be p = qx, so the m2 should be replaced by charge, q2.
 
  • #7
Right.
 

1. What is an oscillating charge?

An oscillating charge refers to a charged particle that moves back and forth in a periodic manner, resulting in a time-varying electric field around it.

2. What is Larmor power dissipation?

Larmor power dissipation is the energy that is radiated by a charged particle as it accelerates due to its oscillating motion. This energy loss is caused by the particle's emission of electromagnetic radiation.

3. How is Larmor power dissipation related to oscillating charge?

The Larmor power dissipation is directly related to the magnitude of the oscillating charge and the frequency of its oscillation. The higher the charge and the faster it oscillates, the more energy will be dissipated in the form of radiation.

4. What factors affect the amount of Larmor power dissipation?

The amount of Larmor power dissipation is affected by the charge and mass of the particle, the strength of the magnetic field it is moving in, and the frequency and amplitude of its oscillation.

5. What are the applications of understanding Larmor power dissipation?

Understanding Larmor power dissipation is important in various fields such as plasma physics, astrophysics, and particle accelerators. It also has practical applications in the design of electronic devices and radiation shielding.

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