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The production of X-rays from peeling Scotch tape is a discovery which has been truly begging for a half-baked application.
However, true usefulness has been limited by the poor beam collimation of the resultant x-rays.
The plenoptic camera, however, creates an image which is focusable after the
image is acquired. Applying this technology to a digital x-ray sensor, "computed tomography" becomes simply a matter of adjusting the focus of the image.
"Scanning" is accomplished by varying the position of the interface line of separation of an adhesive tape with its substrate, that is, peeling the tape off something which is wrapped around the imaging target. A pneumatic cuff could be arranged to perform this job quite nicely. (A braced side prevents compression of the [possibly injured] subject, and a flexible backside allows the expansion to pull the tape off.)
Combined with the ability to electronically send the resulting scan information from a remote location, the device could be extremely useful in allowing diagnosis of intracranial hemorrhage or neck injuries in a timely manner in the instance of emergency or accident.
X-rays from Scotch tape
http://www.nytimes....science/28xray.html
[lurch, Nov 02 2011]
Light Field photography
http://graphics.sta...du/papers/lfcamera/
[lurch, Nov 02 2011]
Personal_20orbital_20ABM_20satellite
[not_morrison_rm, Nov 02 2011]
sealink...............
http://en.wikipedia.org/wiki/Sealink
...........entirely gratuitous Sealink link [not_morrison_rm, Nov 02 2011]
[link]
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You better believe I'm going to be peeling scotch tape in front of my geiger counter tonight. |
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Doesn't the tape have to be in vacuum for this to work? |
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With current state of the art - yes. Maybe. A completely dry atmosphere may also work, but hasn't been proven yet. |
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I think that, with significant atmosphere present,
the energy dissipates by ionising gas molecules
rather than as X-rays. But I'm going to try it anyway.
Will report tomorrow. |
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Generating a CAT image is not simply a matter of focus. |
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The X-ray equivalent of a plenoptic camera would surely involve the use of a mask (as there is no known X-ray equivalent of optical lenses), which would waste nearly all the X-rays, just as a pinhole mask at the source would. |
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And CAT relies on very precise knowledge of the X-ray power of the source. If you could reliable detect X-ray photons as they leave the tape, then reliably re-detect the position and direction of those same photons on the other side of the object, then this would be a breeze; although you would then have to solve one humongous 3D matrix, instead of a series of 2D ones. |
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So you have a few technological challenges. On the bright side, though, once you get this working you will be able to build much better X-ray telescopes. |
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Some plenoptic cameras do use masks. (Search terms: Veeraraghavan non-refractive modulator light field camera.) |
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And one of the interesting things about the Scotch tape is that the X-rays emitted are in a very narrow energy band. Mechanoluminescence has been noted from other tapes (not duct tape, though); but they have different, and wider, energy spectra. |
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I got that to work once, too. You need a dry day, and a dark room. Of course, those were flashes of light caused by the ionisation events that prevent X-ray production in air by slowing down the electrons. |
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[lurch] A narrow energy band is a Good Thing, but more important is very precise control, or at least very precise measurement, of the X-ray flux. |
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Wasting photons at the detector, though, is a Bad Thing, as it increases the dose the patient receives, while still producing a poor image. |
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Didn't we do this in 2009? |
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Erm, so far x-rays from sticky tape has turned up in one BYO Deathstar idea (sealink) and one very poor short story (written by me, so I can say that). |
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Yes, you need a vacuum...so perhaps this might work as the new attachment to one of them Dyson wotsits? |
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// increases the dose the patient receives, while
still producing a poor image.// |
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I disagree; wearing a lab-coat and operating a
machine that peels sticky-tape and produces X-rays
would look really cool. |
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Where can I get 'InstantCat' ? Is it a powder or a cube? Does it mix with hot or cold water? |
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And why do you want to scan it? |
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// And why do you want to scan it?// |
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Not until you scan it. Or maybe not. |
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I think you've just invented Extreme X-Raying...(world suffers major shortage of radiologists as they are mostly in hospital themselves with broken limbs after trying to x-ray volcanoes from a hang-glider....or something like that...) |
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