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Author Topic: Does an accelerated charge emit radiation?  (Read 7896 times)

Offline sorincosofret

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Does an accelerated charge emit radiation?
« on: 21/10/2008 15:25:53 »
Does an accelerated charge emit radiation?

One of the pillars of actual electromagnetism is represented by the following concept: an accelerated charge produce radiation.
The purpose of this experiment is to verify, at least in a qualitative way this base concept.
A CRT and a Klystron tube are necessary.
I remind the principle of working for these devices in order to be clearer.
In case of a CRT, electrons emitted by electron gun travel through rarefied medium and hit the screen. There are some deflection coils, useless for the proposed experiments.
 For an electronician is better to disconnect this deflection coils and prior of experiment the beam is leaved to fall on a small portion of screen. The beam will burn a portion of the screen. The tube will be not useful in the future, but the experiment will be clearer. The experiment is valid even without this trick.

  




Figure 1. CRT tube principle


A Klystron is quite similar to a CRT tube but has a small particularity. Letís cite one of the inventors of this device (source http://www.varianinc.com/cgi-bin/nav?corp/history/klystron&cid=KKIPJHLMFL):
Ö.he thought the first order of business ought to be an explanation of the principle of the klystron. I remember his saying something like this:
"Just picture a steady stream of cars from San Francisco to Palo Alto; if the cars left San Francisco at equal increments and at the same velocity, then even at Palo Alto they would be evenly spaced and you could call this a direct flow of cars. But suppose somshared/ehow the speed of some cars as they left San Francisco could be increased a bit, and others could be retarded. Then, with time, the fast cars would tend to catch up with the slow ones and they would bunch into groups. Thus, if the velocity of cars was sufficiently different or the time long enough, the steady stream of cars would be broken and under ideal circumstances would arrive in Palo Alto in clearly defined groups. In the same way, an electron tube can be built in which the control of the electron beam is produced by this principle - bunching - rather than by the direct control of the grid of triode."
So a scheme of  Klystron tube is presented in fig.2  ( reference and original information is at http://www2.slac.stanford.edu/vvc/accelerators/klystron.html). I have rotated the original image in order to be easier compared with CRT.




Figure 2. Klystron tube principle

The electrons produced by gun (1) are flowing in the direction of beam stop (anode) 5. There is a bunching cavity which regulate the speed of electrons so they arrive in bunches at the output cavity (3) where they produce microwave. The produced microwaves are forced to leave the cavity with the waveguide 4.
The first part of experiment intends to clarify what types of electromagnetic waves are emitted by an accelerated charge.
In case of klystron it is clear that accelerated electrons emits microwave. Are produced electromagnetic waves, the result of electron accelerating or there is another physical process which lay to the basis of phenomena?
In case of CRT, the same accelerated electrons do not produce any kind of electromagnetic waves (Radio, TV or microwave). There is a generation of IR,VIS, or Xray corpuscles as result of smashing accelerated electrons in the screen material.   
 We leave aside the energy released by electrons when they hit the screen in case of CRT or at electron collector in case of Klystron, because the purpose of experiment is to establish the electromagnetic waves emitted by electrons during their fly.
Strange enough, the electrons in the CRT does not emit any kind of electromagnetic waves. For the particular case of burned screen there will not be any visual recognition of CRT tube electron emission.
When the electrons are following their path without bunching, there is no emission of electromagnetic wave at all. This fact can be verified with  Klystron modified tube, too, where the electrons are not bounced.
Why in this case a bunching can lead to electromagnetic waves emission?
The answer is very simple ( fig 3).






Figure 3. Simple case magnetic moments interaction with electromagnetic wave emission

When some electrons are braked (I think this is the term for past of break equivalent german bremsen) and other electrons are accelerated, there is an interaction between electron magnetic moments of braked and accelerated electrons. These interactions lead to oscillation and even to flip of electron magnetic    moments and this produce microwave.
In the proposed theory an accelerated charge does not produce all the time an electromagnetic wave. Generally, electromagnetic waves are produced by flip of magnetic moments.
I leave the conclusion a little bit evasive in order to avoid a further contradiction, as was with electric current and moving charge. In case phenomena will prove that an accelerated charge emits electromagnetic wave, the proposed theory is able to explain this fact, too.
« Last Edit: 22/10/2008 05:13:32 by sorincosofret »


 

Offline lightarrow

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Re: Does an accelerated charge emit radiation?
« Reply #1 on: 21/10/2008 17:21:15 »
Does an accelerated charge emit radiation?
You can bet it.

Quote
...the fascicle is leaved to fall on a small portion of screen. The fascicle will burn a portion of the screen.
You should use the term "beam" instead of "fascicle".

Quote
In case of CRT, the same accelerated electrons do not produce any kind of electromagnetic waves (Radio, TV or microwave). There is a generation of IR,VIS, or Xray corpuscles  as result of smashing accelerated electrons in the screen material.
Maybe you intended "any kind of radio ("radio" in its more general meaning) waves"? Because IR, visible radiation or X-rays are EM waves.

Quote
When some electrons are broken
What do you mean?

Quote
Generally, electromagnetic waves are produced by flip of magnetic moments.
Which kind of EM waves? You have to specify you're talking of microwaves.
However, Electron_paramagnetic_resonance is certainly not what I would define a "General" way of generating microwaves.
http://en.wikipedia.org/wiki/Electron_paramagnetic_resonance

I think you don't have very much appreciation for physicists... They are much more smart than what you think, believe me.  :)
« Last Edit: 21/10/2008 17:23:27 by lightarrow »
 

lyner

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Re: Does an accelerated charge emit radiation?
« Reply #2 on: 21/10/2008 18:11:08 »
In a CRT beam the electrons are not accelerating - so no surprise - no radiation. Actually, there will be a very low frequency field due to the acceleration in the electron gun, I suppose.
When the bunched electrons arrive at the output cavity of a Klystron there is resonance which causes high voltage swings across the gap.  The resulting acceleration ( loading of the modulated beam by the cavity) produces an em wave and this RF energy goes into the cavity and is coupled out into the feeder. There seems to be no contradiction here. It goes according to expectations.
The traveling wave tube amplifier works in a similar way only there is acceleration due to the interaction with the slow wave along the helix.

Sorin; if everyone else in the world is as incompetent as you seem to suggest always, it is amazing that some many bits of technology work so well and so reliably.
Have you actually produced anything which works according to your many and varied theories?
 

Offline sorincosofret

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Re: Does an accelerated charge emit radiation?
« Reply #3 on: 21/10/2008 19:30:54 »
Thanks a lot for the English correction.
I was suggesting the braked electrons (bremselectronen) but I made a grammatical error.
The meaning of the post was to observe what kind of energy emit accelerated electrons. So as I underline it is necessary to leave aside the impact of electrons with screen.
In a hypothetical experiment, if the screen is moved at infinite, a consistent theory should provide what kind of electromagnetic radiation are released when the electron are travelling up to anode.
In the experiment anyone can observe that in a case an accelerated beam of electrons, during his flight in one case radiate electromagnetic waves, and in another case no.
This is the point and not what's happen at the anode.
If you are happy in one case an accelerated beam of electrons does not emits during its trip any kind of electromagnetic wave or photons, and in other case during the trip the beam release electromagnetic wave (no photons). The problem remain the same. 

The other comment is better to be put in the Guinness book. An electron in a CRT tube is not accelerated....

« Last Edit: 21/10/2008 19:36:41 by sorincosofret »
 

lyner

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Re: Does an accelerated charge emit radiation?
« Reply #4 on: 21/10/2008 20:04:33 »
In the DRIFT tube the electron beam in a Klystron is not accelerating. After the electron beam, there is little, if any, acceleration of the beam in a CRT. The field is not very high. In neither case would you expect any measurable radiation. The frequency of any such radiation would be very low.
What do you want from this conversation?
Is Science, yet again, totally wrong?
 

Offline sorincosofret

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Re: Does an accelerated charge emit radiation?
« Reply #5 on: 21/10/2008 21:20:46 »
I want a simple and clear facts delimitation.
In a CRT there is or there isn't a difference of potential between cathode and anode?
How much is this?
There is a simple thermall emission of electrons by cathode or these electrons are accelerated by potential difference between anode and cathode?
By analogy, the same facts delimitation must be made in case of Klystron.
After that, the differences between these two devices must be analysed and the effects must be delimited.
If you will arrive to the conclusion that, both devices are quite similar- for both there is a charge acceleration. Despite their similarity, they produce strong different effect. A logical and common sense mind attribute this difference to a specific cause, and the inventor of the Klystron has made a valid and suggestive analogy. The cause which cause the emission of electromagnetic wave is the bunching of electron fascicle, and not the charge acceleration or deceleration. If you take a charge and accelerate it, in the equation of motion (it is described even in low level manuals) there is not introduced a factor which give you the energy charge loss  as result of acceleration. In an electric field you have the accelerated force and the effect of this force. The same thing at deceleration.
So the bunching produce the electromagnetic waves because a new interaction manifests: the intercation between magnetic moments. 


 Have I said that the science is totally wrong? There are some direction (for example isotopes measurements) which remain valid. Except the experimental part of physics and chemistry, all the rest is more then 95 percent  wrong. For 5 percent it is not worth to stick the bandage, so I intend to change all basis of chemistry and physics.
 
 
 

lyner

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Re: Does an accelerated charge emit radiation?
« Reply #6 on: 21/10/2008 23:45:45 »
Of course there is a high potential which accelerates the electrons in the electron gun in a crt and in a Klystron. But what frequency of radiation does that correspond to? Do you 'know' that it is not produced? Is it relevant? As the acceleration takes place in a metal can, effectively, it isn't going to affect the rest of the operation.
As I said before, where the acceleration does count is in the gaps in the resonant cavities of a Klystron. That produces RF energy - kW of it, in fact!

I don't think you really know what you mean when you insist that magnetic moments are involved. As usual, you are going after a red herring and arrogantly dismissing what people already know. I think this is nothing more than what we call Attention Seeking when children behave like it.
I suggest you read some literature which will explain the matter.
 

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Re: Does an accelerated charge emit radiation?
« Reply #6 on: 21/10/2008 23:45:45 »

 

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