xray sensitive materials

recoder wrote in news:73d22242-0998-4c7a-a78c- snipped-for-privacy@y7g2000yqa.googlegroups.com:

If you're ok with experimenting, try a white LED. LED's can be used as photodiodes, and the phosphors in a white LED will probably fluoresce with x- rays, so the emission might be detectable if you shroud the LED in darkness and it as a photodiode.

If you want something more ideal, specify whether you want the change to be temporary or permanent, as answers might vary hugely depending which you want.

Lostgallifreyan wrote in news:Xns9C44895AD5433zoodlewurdle@216.196.109.145:

and WIRE it as a photodiode...

Just temporary,it has to return to its original state after exposure

More details on what you're trying to do would still be helpful - for instance, what's stopping you from using a good ol' Geiger tube, or a "scintillator" (generally a photomultiplier looking at a bit of sodium iodide or some such)?

Also, how specific does it have to be to X-rays (as in, the idea of watching for what happens with a white LED or some other phosphor- bearing device is a good one, but it's also going to fluoresce when exposed to UV, etc.).

Bob M.

"Bob Myers" wrote in news:h387c3$lk7$ snipped-for-privacy@usenet01.boi.hp.com:

"shroud the LED in darkness" :) Easy to do, many polymers are pretty much transparent to x-rays but will totally exclude light including both far ends of its spectrum, and it should help block electrons too, if you want to check for gamma rays while excluding beta particles. I'm more curious about whether the phosphors in the LED respond well to such shortwave emissions, and whether the LED degrades fatally after limited x-ray exposure. I'm in no position to test this so if anyone can supply answers, please do.

So I see that we have only xray to light conversion and then measure the light (like it is done in scintillators). Interesting..I thought that there were materials that change its resistance, capacitance etc. under exposure..

Note that I didn't say that X-ray -> light was the ONLY possible form of X-ray detection/measurement - it's just one of the more common. Off the top of my head, I am not aware of materials that change resistance, etc., upon exposure to X-rays, at least not in an especially useful fashion, but I suppose that such might exist. Again, what's really needed here is more info about what's really needed here, and why the more usual methods already mentioned can't be used.

Bob M.