# Radiation of an accelerated charge

• fluidistic
In summary, the conversation discusses the behavior of accelerated charges and their emission of photons. The individual asking the questions is unsure of the continuous nature of electromagnetic fields and their relation to the acceleration of charges. They also question the direction and frequency of photon emission during acceleration, and mention the uncertainty principle. They request further information or resources on the subject. Another participant in the conversation mentions having completed undergraduate courses on quantum mechanics and electromagnetic fields, but does not have the necessary books at hand to provide a more detailed answer. They also mention the possibility of confusion between classical and quantum treatments of the subject.
fluidistic
Gold Member
I'm asking this question in the quantum physics part because I'd like a quantum related answer.
When a charge is accelerated, it will radiate photons. In my belief, it must radiate continuously as long as it's accelerated.
Maybe I'm getting a wrong picture. Imagine an electron moving through empty space between 2 opposite charged plates (capacitor). It will be accelerated toward one plate. But since I had not took any serious quantum course, I don't know if the E field between the plate is really continuous or made of EM waves or whatever I can imagine. Thus I'm not 100% sure if the electron will be accelerated at any moment, or by quanta. If it is accelerated at any moment, it should emit continuously I believe... Producing infinitely many photons, which doesn't occur obviously. Therefore I'm missing someting.
Another question: When a charge is accelerated very shortly, its speed will increase, it will emit at least 1 photon... but in what direction? Is that random? Or opposite to the direction motion of the accelerated particle, so that the speed of the charge gets lower than the speed it had right after the acceleration? And if so, is the speed of the particle the same as it was before the acceleration? If so, it would mean that the energy required to accelerate the electron has been 100% converted into a single photon and that the electron's motion remains unchanged... But with Heisenberg's uncertainty principle, I guess I'm far from guessing things right.

I'd appreciate any comment or any link/name of textbooks on the subjet.
Thanks a lot.

Greg Bernhardt said:
@fluidistic did you find any more insight on this topic?
Yes, I completed all the undergraduate courses, including QM and EM. I don't have the books (Zangwill & Jackson) at hand to answer my questions right now.
My intuition regarding my last question tells me that the radiation will have a certain rotational symmetry and will not point randomly nor in a sharp direction.

Otherwise I seem to confuse a classical treatment of an electron with a QM or QFT treatment.

About the quantization of the E field, in QM I dealt with classical E field, but I think it can be quanticized in QFT.

Greg Bernhardt

## 1. What is radiation of an accelerated charge?

Radiation of an accelerated charge, also known as electromagnetic radiation, is the process by which an electrically charged particle produces energy in the form of oscillating electric and magnetic fields as it accelerates. This energy is then radiated outward in the form of electromagnetic waves.

## 2. How is radiation of an accelerated charge produced?

Radiation of an accelerated charge is produced when an electrically charged particle experiences acceleration. This can occur when the particle is subject to a changing electric field, a changing magnetic field, or a combination of both. The acceleration of the charged particle causes it to emit electromagnetic waves.

## 3. What is the relationship between radiation of an accelerated charge and light?

Light is a form of electromagnetic radiation, and therefore, the production of electromagnetic radiation by an accelerated charge is directly related to the production of light. In fact, light is just one small portion of the electromagnetic spectrum, which includes all forms of electromagnetic radiation produced by accelerated charges.

## 4. How does the amount of acceleration affect the amount of radiation produced?

The amount of radiation produced by an accelerated charge is directly proportional to the amount of acceleration. This means that the greater the acceleration of the charged particle, the greater the amount of radiation emitted. This relationship is described by the Larmor formula, which calculates the power of radiation based on the acceleration and charge of the particle.

## 5. What are the practical applications of radiation of an accelerated charge?

Radiation of an accelerated charge has many practical applications, including in the fields of telecommunications, energy production, and medical imaging. It is also used in various technologies such as radio broadcasting, microwave ovens, and X-ray machines. Additionally, understanding the principles of radiation of an accelerated charge is crucial in fields such as particle physics and astrophysics.

Replies
4
Views
2K
Replies
2
Views
1K
Replies
13
Views
2K
Replies
13
Views
2K
Replies
15
Views
2K
Replies
1
Views
814
Replies
2
Views
1K
Replies
4
Views
1K
Replies
43
Views
3K
Replies
7
Views
1K