# Radiation frequency from an accelerated charged particle

My understanding is that a charged particle, when accelerated emits EM radiation. In a situation where a charged particle is briefly accelerated in a straight line it should produce a propagating electromagnetic wave. My question is, what is the characteristic frequency of this wave, and what parameters does it depend on?

• Can you make a simple drawing of acceleration vs time? Is it a square pulse, triangle, gaussian bump...? – uhoh Mar 4 '16 at 2:01

## 1 Answer

Wave produced by brief accelerated motion is not periodic train, but a glimmer. The concept of frequency does not apply to such a wave.

• I understand that it would not be periodic, would it be more like a propagating ramp or step function? Or what is the characteristic length of this glimmer then? – PumpkinPie Mar 4 '16 at 0:02
• phet.colorado.edu/sims/radiating-charge/… Here is a cool simulator I found. As you can see if you accelerate it in a straight line you get this single wave propagating out. I am curious about the parameters that define this waves shape. – PumpkinPie Mar 4 '16 at 0:37
• Transients are expressed as a distribution of frequencies all the time in physics, electrical engineering, acoustics, optics... The peak frequency will be some factor of order unity times 1/t. – uhoh Mar 4 '16 at 1:59
• I clicked "sinusoidal" 20 minutes ago and forgot what I was doing. Nice simulator @PumpkinPie! – uhoh Mar 4 '16 at 1:59