Braking radiation frequency

In summary: Braking radiation, as I understand it, is caused by the deceleration of a charged particle under the influence of an electric field it is entering, in a medium, and not by an electric field it is leaving behind. If the radiation field is unidirectional, then in the case of a decelerated particle, the radiation field would be going in the direction opposite to the direction of the particle. How does this work?In summary, when a charged particle is accelerated, it will emit radiation due to its acceleration. For constant acceleration and a linear trajectory, the frequency of the emitted radiation cannot be determined as it would be a hyperbolic motion. The braking radiation caused by deceleration in a medium has a uniform spectrum extending
  • #1
bocchesegiacomo
19
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When a charge is accelerated it brakes because it emits radiation. If a carge is accelerated with costant acceleration and the traiectory is a line what is the frequency of the emitted radiation? (I think 0Hz but i am not sure)
 
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  • #2
0 Hz is not radiation. The charge will emit some frequency spectrum, the shape depends on the acceleration and the speed (=it changes over time).
 
  • #3
The acceleration law in this case is:
ax=k
ay=0
Where k is a costant parameter and a is acceleration on the axis x and y
 
  • #4
? I don't get the question...
if the charged particle is accelerated, it's going to radiate (and decelerate until "stopped" or somehow keep getting accelerated).
 
  • #5
bocchesegiacomo said:
When a charge is accelerated it brakes because it emits radiation. If a carge is accelerated with costant acceleration and the traiectory is a line what is the frequency of the emitted radiation? (I think 0Hz but i am not sure)

I'm with @ChrisVer . This is very puzzling.

If the charge is accelerating due to some external field, then the charge will radiate due to that acceleration. Without that external agent, the charge won't be accelerating.

Braking radiation happens when the charge is slowing down (decelerating), such as when it enters a material. It is "braking", thus the name.

Your post appears to mix the two, which is very odd.

Zz.
 
  • #6
Thank you
 
  • #7
It may sound simple, but in fact it isn't. Constant acceleration means hyperbolic motion (it's hopeless to solve this problem in the non-relativistic limit since then you get faster-than-light motion of the charge, which simply makes no sense in electrodynamics), and the Bremsstrahlung of this motion is mathematically very delicate, because the worldline is asymptotically lightlike. The mathematical solution is physically well understandable: There is no way to really realize this motion but only for a finite time (e.g., approximately by running an electron through a plate capacitor, which always is of finite extent). So you first consider the problem where the particle is at constant proper acceleration for a long but finite time interval and assume that the particle runs as a free particle before and after this time interval and at the end make this time intervall going to the whole real axis. You find the careful analysis in the paper

J. Franklin, D. J. Griffiths, The fields of a charged particle in hyperbolic motion, Am. J. Phys. 82, 755 (2014)
https://dx.doi.org/10.1119/1.4875195
Erratum: American Journal of Physics 83, 278 (2015)
https://dx.doi.org/10.1119/1.4906577
 
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  • #8
bocchesegiacomo said:
When a charge is accelerated it brakes because it emits radiation. If a carge is accelerated with costant acceleration and the traiectory is a line what is the frequency of the emitted radiation? (I think 0Hz but i am not sure)
According to my book, Electromagnetic Vibrations, Waves and Radiation, by Bekefi and Barrett, for the case of braking radiation, or Bremsstrahlung, there is a pulse of radiation lasting for the duration of the event, t, and by Fourier analysis it has a uniform spectrum extending from zero frequency to 1/t Hz.
The same must presumably happen with an accelerating particle.
My own query is that the radiated E field appears to be unidirectional and extends to DC, and we cannot have radiation at zero frequency.
 

1. What is braking radiation frequency?

Braking radiation frequency refers to the electromagnetic radiation emitted when charged particles, such as electrons, are suddenly decelerated or slowed down. This occurs when the charged particles interact with a material, such as a metal target, causing them to lose energy and emit photons of radiation.

2. How is braking radiation frequency calculated?

The frequency of braking radiation can be calculated using the equation f = (eV)/h, where e is the charge of the particle, V is the potential difference, and h is Planck's constant. This equation is known as the Bragg Equation and is used to determine the frequency of the emitted photons.

3. What factors affect the braking radiation frequency?

The frequency of braking radiation can be affected by several factors, including the charge and energy of the particles, the material they interact with, and the angle of incidence. Higher charged particles and higher incident angles can result in higher frequencies of braking radiation.

4. What are the applications of braking radiation frequency?

Braking radiation frequency has several applications in various fields, including medical imaging, material analysis, and particle accelerators. In medical imaging, it is used in X-ray machines to produce images of bones and tissues. In material analysis, it can help identify the chemical composition of a material. In particle accelerators, it is used to study the properties of subatomic particles.

5. How is braking radiation frequency different from other types of radiation?

Braking radiation frequency is different from other types of radiation, such as gamma rays or radio waves, because it is produced by the sudden deceleration of charged particles. Other types of radiation are produced by processes like radioactive decay or electromagnetic interactions. Additionally, braking radiation frequency is in the X-ray portion of the electromagnetic spectrum, which has shorter wavelengths and higher frequencies compared to other types of radiation.

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