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UltravioletPhotography

X-Ray/Gamma-Induced Visible Fluoresence


Pylon

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Any examples of this anywhere? Why stop at 254nm?

(I am asking this question under the assumption that safety precautions would all be in place, or if safety was not a concern.)

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In order to first be able to even approach such a question, one would have to consider which materials are dense enough to absorb and/or reflect gamma radiation (to a sufficient-enough level), because gamma radiation normally tends to pass through many materials (on the macro level), given its exceptionally high energy levels and tightly-packed wavelengths of about 10 picometers (10−11 meter) or less, (which means that the wavelength of gamma radiation is smaller than the diameter of an atom!) Thus, if gamma radiation freely passes through many materials (on the macro level), then visible fluorescence would not be observed on such a level.

 

Now, on the sub-atomic level, this is different, as gamma bombardment displaces electrons, and can even strip them right from the parent atom's shell! But on such a sub-atomic ("nano", as opposed to "macro") level, visible-fluorescence would not be detected through the conventional means which we use for UVIVF observation and/or image recording, since such observation is dependent on phenomena that extends into the macro (larger than atomic) world.

 

Hence, even if GIVF (gamma-induced-visible fluorescence) is possible, it surely would not be seen with most natural materials (found in nature / unaltered) through typical observational methods (such as our consumer cameras) ... but instead would require an engineered polymer that absorbs and/or reflects gamma radiation (at least to a sufficient degree or ratio of total energy), as well as a specialized imaging device that can view and/or photograph on the sub-atomic level.

 

However, I'm going to go on the assumption that manned space-exploratory vehicles and orbital stations implement such artificially-engineered shielding materials. So, perhaps this can be studied in such a way? (And with the right imaging tools, too.)

 

Just an idea, as I am no expert on this. (I'm guessing, as much as you are, based on limited knowledge.)

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I thought that the shorter the wavelength, the less deep it can penetrate into/through material. For example, doesn't UV-A penetrate deeper than UV-C, on the macro level?

 

but instead would require an engineered polymer that absorbs and/or reflects gamma radiation (at least to a sufficient degree or ratio of total energy), as well as a specialized imaging device that can view and/or photograph on the sub-atomic level.

I would not care if the object I am photographing reflects out gamma radiation, since I can't record those wavelengths with my camera, I'd only care if the object photographed would loose enough energy to reflect out visible light radiation, as that is what I can photograph with a regular camera.

 

Anything to say about Xray-Induced Visible Fluorescence? (or just any wavelength shorter than 254nm?)

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I thought that the shorter the wavelength, the less deep it can penetrate into/through material. For example, doesn't UV-A penetrate deeper than UV-C, on the macro level?

 

Right. But macro penetration is not the same as sub-atomic (or even quantum-level) penetration.

 

For instance, the wavelengths corresponding to UV energy are tightly-packed enough to make it increasingly difficult for them to pass through certain materials LARGER than a single atom over a greater distance (air molecules, for example), and yet, they are simultaneously NOT tightly-packed enough to pass through individual atoms.

 

On the other hand, gamma radiation (and even X-ray radiation, to a more limited effect) now approach wavelengths that are tightly-packed enough to pass through the actual atoms of materials ... and in some cases, such as higher-energy gamma, even punch through atomic nuclei, too! Hence, this corresponds not just to the macro (molecular and multi-molecular) level, but also the sub-atomic level further down in size.

 

So, the "pass-thru" phenomenon you refer to is not linear in its behavior in all wavelength directions. It has more to do with how a shape fits through (or between) other shapes (for the lack of a better analogy). Think of a material as having multiple "keyholes", and a particle / waveform as a "key." They have to well-correspond to each other (in their shapes/sizes), in order to sufficiently interact in certain ways. (Although they do not necessarily have to interact with each other in all ways. It really depends.)

 

If it were increasingly more difficult for gamma radiation (or even X-ray radiation ) to pass through materials, compared to UV, then how would you explain that X-rays pass through many materials more easily (compared to UV, even UV-C), except in the case of sufficiently-dense materials such as heavily-mineralized bone, for instance? :)

 

I would not care if the object I am photographing reflects out gamma radiation, since I can't record those wavelengths with my camera, I'd only care if the object photographed would loose enough energy to reflect out visible light radiation, as that is what I can photograph with a regular camera.

 

Oh, but that's the thing. A material DOES have to be capable of absorbing and/or reflecting a substantial quantity of incoming gamma radiation, in order to also be able to emit lower-energy radiation (such as the Visible band). Otherwise, if much of the gamma radiation passes through the material, undeterred in its path, then there will not even remain enough reflected energy in order to record it ... visible or otherwise.

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Come to think of it, I wonder if visibly-detectable phenomena such as high-altitude aurora ("northern lights", "Borealis", etc.) can be classified as a form of "visible fluorescence?"

 

After all, the material being bombarded is the magnetosphere. And the incoming radiation is clearly energetic enough to interact with, and then reflect, lower-energy visible wavelengths in response to higher-energy solar-wind particles colliding with it from above.

 

Hmmmm ....

 

Perhaps this may be one exceptional example of gamma (and other high-energy cosmic particles) inducing some type of qualifiable visible-fluorescence, produced in nature???

 

Probably not quite the same thing, but I'm just taking a stab, here.

 

(It's more likely that the phenomenon involves multiple interactions, overlapping each other, and not just simply expressed by a type of fluorescence. Hence, in all due likelihood, I am attempting to over-simplify a far more complex process. Or, maybe the classification of such activity simply hasn't been thought of as a type of "fluorescence." Yet.)

 

I only have a fundamental background in cosmology, so, again ... I am no expert. (Even less experience, when it comes to fluorescence. That's a relatively new field for me.)

 

I do know one thing for certain, though: If it weren't for the magnetosphere and ionosphere, we would have been toast, within mere seconds. Literally - toast. Indeed, our Earth's geomagnetic "grid" is one heck of a shield, from the merciless hostility of open space.

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Anything to say about Xray-Induced Visible Fluorescence? (or just any wavelength shorter than 254nm?)

 

I do believe that this would be more realistic (compared to higher-energy gamma). If only marginally so. I think I'll leave it to the more seasoned "gurus" on UVP, to answer that question for you.

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The aurora is excited by incoming charged particles from interplanetary space, not by photons. It could be regarded as a kind of fluorescence (akin to what happens in a neon tube with ionized gas interacting with electrons.)

 

Way back when there was a device called a fluoroscope wherein humans and other animals could stand in the path of an X-ray source with an emitter screen on the other side. The result was a sort of real-time X-ray video of the skeleton. The dosages involved were horrific by modern standards, so the things fell out of favor. However, medical x-rays in the film era were performed with the aid of an "intensifier screen" in front of the film which emitted green or blue light when struck by X-rays (the film's direct response to X-rays was too feeble to use at safe dose levels otherwise.)

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The aurora is excited by incoming charged particles from interplanetary space, not by photons.

 

That's right. Thanks for the correction. ;)

 

Although ... gamma radiation can be part of the total energy equation, when emitted after cosmic rays (which are also types of "charged particles") - collide with the magnetosphere. It's just that cosmic rays are charged particles which originate outside our solar system, whereas the charged particles within solar-wind obviously come from coronal ejections from the sun.

 

So, are we to conclude that photons are not the only particles that are capable of inducing visible-fluorescence??? In which case, this was along my line of thinking ... and thus leading to your next statement as ...

 

It could be regarded as a kind of fluorescence (akin to what happens in a neon tube with ionized gas interacting with electrons.)

 

Precisely. You just described a more fitting example, here. Thanks!

 

Way back when there was a device called a fluoroscope wherein humans and other animals could stand in the path of an X-ray source with an emitter screen on the other side. The result was a sort of real-time X-ray video of the skeleton. The dosages involved were horrific by modern standards, so the things fell out of favor. However, medical x-rays in the film era were performed with the aid of an "intensifier screen" in front of the film which emitted green or blue light when struck by X-rays (the film's direct response to X-rays was too feeble to use at safe dose levels otherwise.)

 

So, then, is this resulting emission of blue-green visible energy from the transmission-enhancement screen material, in response to X-ray bombardment, qualify as a form of "fluorescence?"

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I have worked with X-ray luminescence for several gem materials. The images were generally in the macro range but overall the quality was not so good due to shooting through "lead" glass.

 

I have also worked with 220nm UV excited luminescence to photograph growth structure in diamonds (many images published in Journal of Gemology). Filters were very expensive and didn't last long due to UV damage.

 

Visible (also UV & IR) luminescence is an emission process (not a reflection process) that can be excited by many different sources, electricity, sound, heat, UV, visible light, X-ray, electrons, protons, gamma rays etc. I have worked with all but the last two, however, having seen a proton aurora, I guess I could include protons.

 

An aurora is an emission phenomena resulting from ionized gas ("natures neon") and that qualifies it as a form of luminescence.

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If you need a gamma ray flash, just wait for the next thunderstorm and you might be lucky :) :

 

https://en.wikipedia...gamma-ray_flash

 

Yes, indeed. The giant static-electric arc from a lightning discharge is typically hot enough to incinerate an immensely large volume of air (thus energizing and ionizing the entire lightning channel) to yield some gamma radiation, as a portion of a much broader spectral emission.

 

However, given that the arc is such a short-duration burst (mere micro seconds), the net gamma emission is too insignificant to matter with regards to the post's interests (in terms of practical application.) ;)

 

On the other hand, your question caused me to ponder something of related interest: One has to wonder of those higher-altitude (and still quite mysterious) "sprite" phenomena which occur high above powerful thunderstorms - and in a multitude of eerie and hauntingly beautiful patterns of blues and greens (sometimes even reds) could have any relation to the possibility of gamma-induced visible-fluorescence. Recent insights (from scientific testing done with high-altitude plane flights and using sophisticated instrumentation) reveal that solar wind may play an important role in sprite formation, too. However, that it takes the additional electrical potential of a powerful thunderstorm (especially with the formation of towering cumulonimbus "anvil" clouds) to ultimately elicit the formation of these highly-elusive spites ... one has to wonder if higher-energy photonic emission (such as gamma) may also be crucial to the process of formation.

 

While I do understand that ionized atoms and high-energy positrons are probably the biggest contributor ... the point remains that visible phenomena do result. Thus, there may be some overlapping effects, some of which may be photonic-related fluorescence.

 

Bottom line is that lightning is very hot. In some cases, even hotter than the surface of the sun, within some particularly energetic discharges. And given that the sun emits gamma radiation, as a component of its total spectral emission, then perhaps those more mysterious high-altitude "sprites", "blue jets", et al., could be partly explained by a form of visible fluorescence (if only for a very fleeting moment, that is.)

 

Things to ponder .....

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I have worked with X-ray luminescence for several gem materials. The images were generally in the macro range but overall the quality was not so good due to shooting through "lead" glass.

 

This makes an excellent point, in the issue that even if a practical process were developed for inducing visible fluorescence, via gamma or x-ray illumination, the fact remains that the tools on the recording end (the lens and camera, heck - even the filter) would also have to hold up to such an increasingly more hostile environment. After all, higher-energy photons can damage sensitive electronic components (especially from prolonged use) ... with the exception of equipment that is specifically designed to be shielded from such use. But then, we consumers generally have no access to such equipment, nor would it even be financially feasible to do so. (At least, for most of us.)

 

Furthermore, the imaging lens and filters(s) would also have be capable of attenuating (shielding) from any reflected gamma / x-ray energies, so as to not corrupt the final visible-fluorescence image. Otherwise, the resulting image would be contaminated by other energies, besides the visible bandwidth.

 

There are very likely many more hurdles to be overcome, in order to effectively elicit and record visible fluorescence from gamma and/or x-ray bombardment. It would thus make one wonder: Why even go through the trouble??? (when we already have an easier methodology in place, with UV-induced visible fluorescence.)

 

Hence, my conclusion to Pylon's originally posted question - "Why stop at 254nm?" (at the very top of this post) - would be: "Why not stop there?" (Given the fact that the disadvantages begin to increasingly outweigh any advantages, as one moves towards increasingly higher energy).

 

It would be akin to asking - "Why not use an oncoming train to crack open your can of tuna?"

 

Well ... why should I, when a can opener is already a well-established and far more practical approach? :D

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Because the train method is more fun.

 

Hah! Good one. :lol: :lol: :lol:

 

Although ... while the train method may certainly seem "more fun" (at first) ... chances are, that the fun will soon fade, once you realize that you won't get to eat the contents of the can. :unsure:

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In the situation I was using X-ray generated visible fluorescence, it was to characterize properties in order to provide identification criteria.

 

Indeed.

 

However, the methodology used for material identification does not necessarily translate into the realm of aesthetic / artistic photography, as I am sure you already know. :)

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  • 3 weeks later...

What about Extreme Ultraviolet (10-124nm)?

 

It says on Wikipedia "In air, EUV (Extreme Ultraviolet) is the most highly absorbed component of the electromagnetic spectrum, requiring high vacuum for transmission.".

 

I understand this to mean one of two things:

 

1) Emitting EUV would not work because the light could not travel through air. Emitting Extreme UV would need to be done in a vacuum in order to photograph any fluorescent or reflective effects.

 

2) If air is visibly fluorescent from EUV, then if you turned on a EUV light source in a room, you could see the visible fluorescent effect strongest near the light source, then it would decrease as it moves further away from the light source. You could literally see the light "fill up" space/air, unlike any other type of light, which you normally only see after it hits a surface. If air is not visibly fluorescent, then maybe it is UVA/B/C fluorescent, and you could photograph this effect using a UVA/B/C imaging system.

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I'm pretty sure it's mostly option (1) there, Pylon, based on the rest of the text in that article. It does mention that sometimes it strips an electron or two off, which means they can then recombine and emit some light, but I bet that is a smaller effect than stuff just getting absorbed. (If you have a process that requires multiple steps to happen, the probability of it happening tends to be smaller than a single step process.)
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enricosavazzi

What about Extreme Ultraviolet (10-124nm)?

 

It says on Wikipedia "In air, EUV (Extreme Ultraviolet) is the most highly absorbed component of the electromagnetic spectrum, requiring high vacuum for transmission.".

 

I understand this to mean one of two things:

 

1) Emitting EUV would not work because the light could not travel through air. Emitting Extreme UV would need to be done in a vacuum in order to photograph any fluorescent or reflective effects.

 

2) If air is visibly fluorescent from EUV, then if you turned on a EUV light source in a room, you could see the visible fluorescent effect strongest near the light source, then it would decrease as it moves further away from the light source. You could literally see the light "fill up" space/air, unlike any other type of light, which you normally only see after it hits a surface. If air is not visibly fluorescent, then maybe it is UVA/B/C fluorescent, and you could photograph this effect using a UVA/B/C imaging system.

Alternative 2 would be visually perceived as a region of "fogginess", haze, or a "halo" around the radiation source (if strong enough to be visually perceived at all). A light suspended in slightly muddy water would be the closest thing that gives an easily reproducible, comparable visual effect.

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