How exactly are X-Rays produced?

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Discussion Overview

The discussion centers on the production of X-rays, particularly in the context of cathode ray tubes and particle accelerators. Participants explore various mechanisms by which X-rays can be generated, including the roles of electron acceleration, interactions with metal plates, and collisions with other electrons.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that X-rays are produced when accelerated electrons emit energy, though this is debated regarding the energy range of the emitted radiation.
  • Bremsstrahlung is discussed as a mechanism for X-ray production when electrons decelerate upon hitting a metal plate, with some clarification that this process involves deceleration rather than acceleration.
  • There is a claim that X-rays can be produced when an electron collides with a core-level electron in an atom, knocking it out and causing other electrons to transition and emit radiation.
  • Some participants express uncertainty about whether accelerating electrons absorb or emit radiation, with references to classical electrodynamics suggesting that non-zero acceleration leads to emission of electromagnetic waves.
  • In particle accelerators, energy loss is discussed in relation to Bremsstrahlung and the bending of particle paths, with some clarification that these processes are distinct.

Areas of Agreement / Disagreement

Participants express differing views on the mechanisms of X-ray production, particularly regarding the roles of acceleration and deceleration. There is no consensus on the accuracy of certain claims, and some points are clarified while others remain contested.

Contextual Notes

Some claims rely on specific definitions of acceleration and radiation emission, and there are unresolved distinctions between different types of radiation processes in particle accelerators.

Arup Biswas
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I found that in a cathode ray tube accelerated Electrons produce X rays! Now it can be in 3 ways
1) When the electrons are being accelerated by increasing Voltage...then according classical theoy they should radiate energy! It may be the X ray
2) When it reaches the metal plate there will be the acceleration due to nucleus, it may produce X rays, which we call Bremsstrahlung
3) If the electron strike another electron and seize it's place then its energy also converts into X ray!
Pls help me where am I wrong in my concept?
 

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Your 2) and 3) both happen. In 1) the acceleration is comparatively quite gentle, so any radiation would be far below the x ray range. Also, it is accelerating so I would think it would be absorbing radiation rather than emitting it, but I am not sure about that point.
 
Arup Biswas said:
2) When it reaches the metal plate there will be the acceleration due to nucleus, it may produce X rays, which we call Bremsstrahlung

Actually, it is not "acceleration", but rather deceleration. Bremsstrahlung is "braking radiation", i.e. while it is slowing down.

3) If the electron strike another electron and seize it's place then its energy also converts into X ray!

Again, a bit inaccurate. It has to be one of the "core level" electrons in the atom, some time called the K-shell or deeper. It doesn't seize its place, but rather knocks it out of place. Then, this state is empty, the other electrons in the atoms will decay down to this state, emitting EM radiation. Due to the nature of the transition into this state, this is when x-ray is emitted.

You may want to refer to this:

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/xrayc.html

Zz.
 
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Dale said:
Also, it is accelerating so I would think it would be absorbing radiation rather than emitting it, but I am not sure about that point.

an accelerating electron emits EM ... standard for an AC ( RF) circuit :smile:
 
Hello

Dale said:
Also, it is accelerating so I would think it would be absorbing radiation rather than emitting it, but I am not sure about that point.

In classical electrodynamics, if acceleration is not zero, it will emit em waves (independently on the sign of the acceleration).

In a particle accelerator (specifically betatron, synchrotron, and similar), they loss a lot of energy while trying to give more energy (momentum) to the particles.
https://en.wikipedia.org/wiki/Synchrotron#Principle_of_operation

Electron/positron accelerators may also be limited by the emission of synchrotron radiation, resulting in a partial loss of the particle beam's kinetic energy. The limiting beam energy is reached when the energy lost to the lateral acceleration required to maintain the beam path in a circle equals the energy added each cycle.

Greetings.
 
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ORF said:
In a particle accelerator (specifically betatron, synchrotron, and similar), they loss a lot of energy by "Bremsstrahlung" trying to give more energy (momentum) to the particles.
https://en.wikipedia.org/wiki/Synchrotron#Principle_of_operation

I don't want to be picky, but what you wrote and what you quoted from Wikipedia do not match.

"Bremsstralung" happens when a charged particle is decelerated very quickly. This happens in, say, when a charge particle is stopped by a piece of material. This is a major issue in shielding for particle accelerators.

The loss of energy in synchrotron, betatron, cyclotron is due to the BENDING of the path of the charged particles, which is a form of acceleration. There is no loss in kinetic energy of the charged particles. This is, technically, not usually categorized as Bremsstralung radiation.

Zz.
 
Hello

Sorry, you are right. Thank you for the clarification [I have removed the reference to bremsstrahlung]

Greetings.
 
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