Gerald,
let me step in here.
Not wanting to judge the behaviour of even "an individual" in terms of his/her way to express his/her opinion in scientific matters of subject or even trying to understand the split minds of others, thus let me come straight to the point.
I had some sleepless nights within the recent past. This due to the more I am trying to understand the entire topic "generation of radio nuclides by x-rays" or to quote an individual:
"...Xray machines created radio isotopes...".
Why..?
Hmmm... I guess you know me well with these things. Trying to tie all these loose ends...
Good, let me come to the fact that - to the best of my knowledge - work pieces having greater wall thicknesses may be examined by using x-ray sources as accelerators.
Please correct me when I'm wrong but as far as I know from the past (at least I mean to have read something ~ 2 1/2 decades ago) for material or work piece examinations "betatrons" are used. So if I understood the matter correctly x-rays are the result of bombarding a target within the accelerator. After the - in case of using an electron accelerator as a betatron - accelerated electrons have impinged upon the target material (what ever it is) different interior as exterior phenomena can be detected.
When remaining with the exterior detectable ones a very particular phenomenon is the emission of electromagnetic wave radiation, which again can be designated as "x-rays". And here begins my confusion which I'll try to order as follows:
- When we are reading of accelerators one can read of e.g.:
"Linear Accelerators (linacs) are linear devices used to accelerate atomic and sub-atomic particles to high velocities."
I guess it might be of great influence if "atomic" - read high mass afflicted e.g. protons - or even "sub-atomic" particles - read low mass afflicted e.g. electrons - are being accelerated. I guess due to the conservation of mass and impulse valid with both particles, both may have different impacts upon the target interacting with when presuming both will have the same value of velocity been accelerated to.
- The above is important - as I mean - as it leads to come to the very emotionally discussed sub-item of the "generation of artificial radio nuclides" by even using an accelerator. Or in other words: "Do accelerators for material examinations generate artificial radio nuclides having low half-life periods?".
- Presumed that the kinetic energy of a particle accelerated, depends to its mass and presumed that the energy level of an "atomic" or "sub-atomic" particle is described by using the unit "electron Volt" (eV), one may - theoretically - calculate the particle's energy been accelerated up to a particular level. Then, presuming further, we might approach if the particle energy in "eV" might suffice to "create radio isotopes", as also the binding energy within the atomic nucleus is expressed by using the unit "eV". So far I mean to have understood that, if we can reach particle energy levels - achieved by accelerating the particles - high enough to exceed the binding energy levels within the nucleus, and steering these accelerated and high kinetic energy containing particles to interact with the nuclei of a - e.g. metallic - material, we may assume that radio nuclides can be created even by the reaction between the accelerated particle and the material's atomic nuclei (either emission of neutrons - (gamma, n) - or emission protons - (gamma, p) ).
- And quasi here begins the confusion which has taken my sleep over the past nights. As we know that there are different principles to accelerate different particles, having different masses and thus different impacts upon the material (target), we can suppose that accelerated electrons interact in a different way with the material structure as e.g. accelerated protons do. This is, where electrons create electromagnetic wave radiation (Bremsstrahlung --> X-rays) by being impinged to the material, accelerated heavier particles again interact with the material's atomic nuclei and initiating the emission of e.g. neutrons, or in other words creating radio isotopes. The first thus, electron acceleration, leads to an interaction with the "atomic shell" the latter again leads to an interaction with the nucleus itself or even to a creation of - in particular case -artificial radio nuclides.
- So far so good. To trying to clarify the subject - if even possible - let us presume that we do use an electron accelerator even a betatron and electrons do hit the target. Even though they may reach high energy levels ( ~30 MeV), they may not have - and this is my confusion - the ability to create radio nuclides due to they are "just" interacting with the atomic shell and the result itself may be detected as Bremsstrahlung or characteristic "X-Rays". And all this, although the energy content of the electrons is quite comparable with the energy levels being achieved with the proton acceleration. This again is proved to be able to create radio isotopes by even interacting with the atomic nucleus itself. Hence, finally I guess it is to be found with the mass of the particles themselves, which were - at least in my humble understanding - a quite reasonable explanation.
- However, let us assume furthermore that the energy output (e.g. MeV) with both accelerator types (electron- or proton) were similar but the type of energy carrier itself were different (Electromagnetic wave radiation [x-ray] and Particle radiation), then - at least in my understanding - both should be different. Firstly the target itself being integrated within the accelerator and the way of interaction of the accelerator's "output" with the material to be ND-examined. Where high energy X-rays - as the result from an electron accelerator - should normally interact just with the atomic electron shell, high energy gamma radiation whereas - as a result of a heavy particle accelerator - should normally interact - at least partially - with the atomic nucleus of the material to be tested, and thus, finally, might eventually create some sorts of short half-life period radio isotopes.
- But... is this really the case? Finally, at least in my understanding, the type of particle itself been accelerated should actually be of a secondary order since what actually counts should be the energy, even measured in our case in "eV", the material to be investigated is subjected to. In other words. An "x-ray" (as a result from an electron accelerator) of an energy of 20 MeV should act the same way upon the material being examined as a "gamma ray" having an energy of 20 MeV. Or - what I have considered as well - is an "x-ray" - even an electromagnetic wave - also acting as a "wave" i.e. having no explicit particle character e.g. as a neutron containing the similar energy? And only the high energetic particle (e.g. neutron) can interact with the material structure on an atomic nucleus level and can create thus short half-life period radio isotopes? Otherwise quantum mechanics speaks of wave-particle duality, thus, at least from a layman's standpoint - which is mine - both energy values should have similar results when being superimposed to the material structure. Thus - even presuming the energy level of an x-ray is > the (material's to be examined) atomic nucleus binding energy threshold value - an interaction between the particular material's atomic nucleus and the photon radiation coming from the energy source (accelerator) should be feasible.
- So I have to finally come back yet to who "weld39" is. If he/she is "prasad" - well-known and appreciated from past discussions dealing with a similar topic - he/she has tried to point out that it is not possible to create radio isotopes by using an appropriate accelerator for NDE. Well, I do really not know whether the element "iron", as the basis of the most materials we are dealing with, might interact with a high energy x-ray and thus radio isotopes may be generated from this interaction, but I mean to know that elements below the iron nucleus binding energy level (having lighter nuclei) e.g. carbon - which may be, as well-known, an alloying element with steel - might be influenced in a way to even creating short half-life period isotopes lying within the 20 minute range you have stated with the discussions at that time.
- And finally. I am honest when I am saying that I have no idea, what kind of accelerators are available for material testing nowadays. What I even know - as already mentioned above - is, that betatrons - or even electron accelerators - have been used stationary for NDE of large wall thickness parts. But as I said, this information is ~ 25 years old and I haven't "googled" or used the internet by any means to finding out what's suitable today.
So as the conclusion of my short input I'd like to say. When firstly considering the "energy level" of a photon radiation as being the primary source for the creation of radio isotopes and the radiation source itself (either an electron [low mass particle] or proton [high mass particle]) accelerator secondarily, then - at least in my understanding - a creation of short-life radio isotopes having a lower nucleus order number than iron may be possible. If however, the character of the energy carrier (particle = proton or electromagnetic wave = electron) plays the major role for the creation of radio nuclides then - at least in my eyes - it might be imaginable that a betatron as an electron accelerator and thus an x-ray generator does not have the capability to create radio nuclides even though it is capable to achieve energy levels up to 30 MeV which were usually sufficient to influence the atomic nucleus in a way to separate a heavy nucleon either a neutron (gamma, n) or a proton (gamma, p) from the core.
Would be great Gerald, if you could shed a light on this to pointing me in the right direction!
Best,
Stephan
Go back to the hole you crawled out from CLOWN - who doesn't even make anyone laugh!!! ;( ;( ;(
You are off to great start. WELDcome!!!
I'm losing track here, is weld39 the old 3.1/3.2 inspector?
All three are the same guy.
Gerald, 
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