Gamma and beta radiation in accelerators?

[Dr.AbeNikIanEdL]

Rather, the issue here is that "if you call this X, then it MUST only come from this process".

As I have tried to say before, I think you are the one who mistakes a change in label as a claim of actual physics here. This sentence in the current context is

“If you call photons from nuclear reactions Y, and all other photons X, then Y must only come from nuclear processes.”

Which obviously is true.

Common definition of Gamma Ray is actually "origination form a nucleus i.e. nuclear), which included radioactive decays.

Well, I think you should also acknowledge that this definition if of little use in other fields, where you either don’t precisely know or do not care what the source of radiation is, but just that it is around and has a certain energy. There is not one “common” definition in general, and neither of the definitions is really “better” in general. But insisting on a particular definition in the wrong context will not get you anywhere.

 

[geoelectronics]

I edited the post while you were answering.


And I have no problem with that, as I have no problem calling gamma rays highly energetic photons that do not come from a radioactive decay. Like gamma rays created from an interaction of cosmic rays (which everbody knows are not really rays) with the atmosphere.

I'm not expert in high energy particle collisions and don't claim to be.
But I can tell you that highly energetic photons come form all sorts of other particle interactions NOT within the nucleus. Each one has a specified name, and defined characteristics, but otherwise once away from the source they can't casually be identified as to what was that source, but under close measurement, probabilities can be assigned as to the possible source.

Please, and I'm sincere, show me the particle collision caused by Cosmic Rays and would like to make a stab at a comment.

I do disagree about everyone knows Cosmic Rays are not rays. The discoverer's didn't- no student intuitively knows, and the science community should lobby to change/correct their name. Something like Cosmic Wind, while not scientific, gets the right idea across perfectly. Maybe Cosmic Plasma Wind is better.

George Dowell

 

[ZapperZ]

Huh? Would you call 100 MeV electrons "beta rays"? I can show you where that is in an accelerator.

Zz.

 

[ZapperZ]

Would you mind tell me if you actually understood the main point that I made regarding your restricted definition of gamma "ray" or "photons"?

Please tell me where exactly did I make such a restricted definition. In fact, I'm the one who was arguing against making the restriction that "gamma rays" must come only from specific processes.

And again, is 100 MeV electron considered as "beta rays"?

Zz.

 

[mfb]

@ZapperZ: There are two mutually incompatible ways to define x-rays vs. gamma rays. That's just how it is. You are more familiar with the classification by energy (which I prefer as well), but other fields use a classification by source.
Yes, that means you don't know if a 650 keV photon would be called x-ray or gamma ray if you classify by source. So what? You have the same e.g. for synchrotron radiation: You can't tell if a photon is synchrotron radiation or not just by looking at its energy.

 

[hutchphd]

Excuse my impertinence but what in heck is this discussion about? Perhaps an application of Feynman would help:

http://www.fotuva.org/feynman/what_is_science.html

 

[ZapperZ]

@ZapperZ: There are two mutually incompatible ways to define x-rays vs. gamma rays. That's just how it is. You are more familiar with the classification by energy (which I prefer as well), but other fields use a classification by source.
Yes, that means you don't know if a 650 keV photon would be called x-ray or gamma ray if you classify by source. So what? You have the same e.g. for synchrotron radiation: You can't tell if a photon is synchrotron radiation or not just by looking at its energy.

@mfb: please read what I have written. I never dismiss the fact that there can be different classification. It is the others who claim that ONLY radiation in that frequency coming from nuclear process can be called "gamma rays", and that if that same frequency did not come from nuclear radiation, then it can't be called as such!

I'm not the one being narrow and RIGID with the definition here!

Zz.

 

[mfb]

It is the others who claim that ONLY radiation in that frequency coming from nuclear process can be called "gamma rays", and that if that same frequency did not come from nuclear radiation, then it can't be called as such!

That's one of the two classification schemes. That statement is only true within that classification scheme, of course (and it is the definition in that scheme, so it is trivially true).

 

[ZapperZ]

That's one of the two classification schemes. That statement is only true within that classification scheme, of course (and it is the definition in that scheme, so it is trivially true).

Yes, but why are all these being addressed to me? Let me reemphasize that I wasn't the one being rigid with the definition. I was the one who couldn't care less if it was called a Twinkie!

Zz.

 

[mfb]

Yes, but why are all these being addressed to me?

Because your posts seemed to claim that this other definition doesn't exist, or must be wrong. At least that's the impression I got.

 

[ZapperZ]

Because your posts seemed to claim that this other definition doesn't exist, or must be wrong. At least that's the impression I got.

Where did I say that?

Zz.

 

[mfb]

In post 7, second paragraph, in post 11 and 14, and a few more.

 

[ZapperZ]

In post 7, second paragraph, in post 11 and 14, and a few more.

sorry, but I do not see it. Look closely. I was disputing the insistence that gamma rays was rigidly defined as being only from nuclear reactions. I repeatedly stated that THAT is not the only definition of it. I NEVER stated thatsuch usage was invalid.

zz

 

[vanhees71]

@ZapperZ: There are two mutually incompatible ways to define x-rays vs. gamma rays. That's just how it is. You are more familiar with the classification by energy (which I prefer as well), but other fields use a classification by source.
Yes, that means you don't know if a 650 keV photon would be called x-ray or gamma ray if you classify by source. So what? You have the same e.g. for synchrotron radiation: You can't tell if a photon is synchrotron radiation or not just by looking at its energy.

Hm, after all photons are bosons and thus indistinguishable. Just given a 650 keV photon you can't say, where it comes from. So if a distinction of photons by different names, it makes only sense to disinguish them by some intrinsic quantity of the photon, and in this case it's usually energy.

You may also ask whether "bremsstrahlung" is only right for emission of em. waves when a particle is decelerated, i.e., is it wrong to call "cyclotron radiation" (where the electron is accelerated) "bremsstrahlung" either? After all in physics both is due to acceration of charged particles. No matter whether the speed gets larger or smaller it's acceleration ;-)).

 

[Dr.AbeNikIanEdL]

Hm, after all photons are bosons and thus indistinguishable. Just given a 650 keV photon you can't say, where it comes from. So if a distinction of photons by different names, it makes only sense to disinguish them by some intrinsic quantity of the photon, and in this case it's usually energy.

Well, you can justify your preferred naming scheme as well as you want, that is not changing the real world fact that other naming schemes are in place and used by the some part of the community.