Sciencemadness Discussion Board

X-ray device powered by scotch tape...

evil_lurker - 23-10-2008 at 08:55

Was reading this:

http://news.yahoo.com/s/ap/20081023/ap_on_sc/sci_scotch_tape...

Apparently if you peel scotch tape in a vacuum, you get x-rays... enough x-rays that you can actually make a pic of a body part!

If this could be perfected, just think of what it could mean for medicine.

12AX7 - 23-10-2008 at 09:15

Neat, and it makes perfect sense. Goes to show you how inside amazingly mundane objects lurk some of the most surprising physical phenomena. It's just like that report of fusion by heating crystals. Very similar actually, since it's due to that stress and transfer of charge kind of thing.

...Heyyyy, scotch tape in a near vacuum with D-T gas at low pressure: FUSION! :D

Tim

sparkgap - 23-10-2008 at 09:29

Another report: http://www.msnbc.msn.com/id/27323869/

sparky (~_~)

chemkid - 23-10-2008 at 11:07

Thats awesome! I love common things doing extrodinary things, because they are totally with in reach of the amature. Just found a new project!

Chemkid

Trifluoroacetic - 23-10-2008 at 14:46

I noticed along time ago that if you pull a band ade wrapper apart fast enough in the dark a blue glow is produced. I assume this is also due to the production of spatial charges.

not_important - 24-10-2008 at 03:18

The original report is here http://www.nature.com/news/2008/081022/full/news.2008.1185.h...

chief - 24-10-2008 at 06:48

I don'tbelieve it:
==> x-rays can be emitted from the inner shells of an large enough atom, usually from the inner shells ("K-shell")
==> thatfor the atom involved has to be heavy enough ! No x-rays from light atoms such as C,O,H,N ..., because the energy-niveau-differences are not in the x-ray-region ...
So even although the voltage may be high enough (several kV) to yield -rays when applied to an X-ray-tube, nothing will happen with the scotch-tape alone. Maybe their vacuum-chamber has parts of metal, then the x-rays would come from the metal-surfaces(hit by electron, that were accelerated by the voltage of the scotch-tape-unwinding)

Probably: It's just that stupid "guerilla-marketing": "Scotch-tape" burns itself into memory...

[Edited on 24-10-2008 by chief]

On the other hand: X-rays may also be created by accelerating/decelerating charge-carriers; not surein the moment, if that's forbidden for scoth-tape ...

[Edited on 24-10-2008 by chief]

And now I saw the video: The image of the finger islighter at he outer borders, not at the center, where the tape was ...
So: The x-rays seem to have been emitted _not_from_the_tape_, instead from the metal of the vacuum-chamber !

Just another way of generating the high-voltage necessary for x-ray-generation. Nothing new ... poor "nature"-printing-product: They couldn't find this mistake ?? :D

[Edited on 24-10-2008 by chief]

12AX7 - 24-10-2008 at 10:43

Good point, the x-ray in the photo must be a positive of the original image.

Oxygen is probably the heaviest atom in scotch tape, and since Z = 8, E ~= 13.6 * 8^2 = 870 eV, maybe soft x-rays, but certainly more penetrating than UV.

Tim

Polverone - 24-10-2008 at 11:05

Quote:
Originally posted by chief
And now I saw the video: The image of the finger islighter at he outer borders, not at the center, where the tape was ...
So: The x-rays seem to have been emitted _not_from_the_tape_, instead from the metal of the vacuum-chamber !

Just another way of generating the high-voltage necessary for x-ray-generation. Nothing new ... poor "nature"-printing-product: They couldn't find this mistake ?? :D

Are you joking? The darker inner part of the finger-image is of the bone. Bone blocks x-rays better than the surrounding flesh.

The x-rays are said to be about 15 keV, so it's bremsstrahlung.

Edit: even if the metal of the vacuum chamber is required, this is still an interesting advance. It's certainly the simplest x-ray generator I've ever heard of.

[Edited on 10-24-2008 by Polverone]

chief - 24-10-2008 at 11:49

I'm talking about the range of the image where the finger is not depicted. It's quite a difference towards the border.

If the x-rays are 15 kV: Thats the voltage to expect from this tape-unrolling-setup.
Would "BremsStrahlung" occur from decelerating charges in plastic? The deceleration ought to be fast enough, else just a lot of photons would be created, the 15 kV distributed among them ...

And then: It's not as simple as a classical x-ray-tube:
==> The first one was probably made out of a flask with 2 openings, from the chemistry-departement.
==> just evacuated,with the electrodes there in

A quite high vacuum may be achieved even without a vacuum-pump: Just flood the flask with CO2, having placed some CaO inside it before: The reaction gives the vacuum, and maybe a high one!

So there is the most simple x-ray-setup on the world ! Just to be connected to an high-voltage-source. Besides: With those non-glowing-emission tubes the vacuum ought to be not too high, so there still is a means of conducting the current.

I have 2 real X-ray-tubes around, but I'm always too lazy to experiment with them ...

[Edited on 24-10-2008 by chief]

bfesser - 24-10-2008 at 12:29

Quote:
The darker inner part of the finger-image is of the bone. Bone blocks x-rays better than the surrounding flesh.


They used a dental x-ray imaging detector.

[Edited on 10/24/08 by bfesser]