# How charge acceleration is dependent on radiation of electromagnetic wave?

1. Apr 17, 2012

Is there any mathematical relation between the value of charge(ie proton/electron) and radiation which is being emitted? I m sure energy is conserved in this process so does that mean electron decelerates in process of radiation ?

2. Apr 17, 2012

### Staff: Mentor

If you have a particle with a larger charge (but otherwise identical), you can expect that it radiates more photons than another particle.

Energy conservation is a completely different area.

Deceleration is the same as acceleration (in terms of "increases absolute velocity"), just for different observers.

A free electron cannot emit a real photon without violating energy or momentum conservation. However, it can exchange virtual photons or emit real photons if more particles are involved in the process.

3. Apr 17, 2012

Well I've read that a accelerated charge releases EM wave..By doing so,charge loses its energy right? Which inturn results in decrease of velocity(deceleration as I meant)..So whats the relation which holds with energy released in this process and amount of acceleration..Hope u get my claim..THanking you

4. Apr 17, 2012

### Staff: Mentor

I think you mean synchrotron radiation. Yes, accelerated electrons can radiate away energy and therefore become slower (more important: less energetic).

5. Apr 20, 2012

Does this mean violation of conservation of energy..?!?!!

6. Apr 20, 2012

### Staff: Mentor

No, it means that a free electron does not emit a real photon.
Note that an electron in an electromagnetic field is not free, but can interact with other photons. The process "electron+photon -> electron+photon with different momenta" is possible.

7. Apr 20, 2012

### Bob S

The electron can be accelerated (decelerated) either transversely (synchrotron radiation) or longitudinally. Whenever there is acceleration, there is radiation. The rate of energy loss is
$$\frac{dW}{dt}=-\frac{e^{2} \dot{v}^2}{6\pi\epsilon_o c^3}$$ where $\dot{v}$ is the acceleration.