X-Rays from Scotch Tape

The argument goes like this. If you unroll scotch packing tape in the dark you can see sparks of light coming off the unwinding tape. So a graduate student and a post doc at UCLA thought about measuring the spectrum of light coming off the tape and apparently as it unsticks it produces X-rays. I noticed this on the BBC and it also made other news services (AP, and AFP). They did this by putting the tape into a vacuum chamber and had it mechanically unwind. They took a X-Ray photoplate and exposed their fingers to it and got a decent X-Ray image of their finger. Apparently it produces X-Rays on the level of a dental or medical X-Ray machine.

First: I wonder what is the process that creates these X-Rays and whether or not they are particular to the glue being used on the tape, or if the same effect can be seen with other materials. If this type of thing comes up in many more materials then perhaps it will change we perceive and relate to radiation.

Second: Wouldn't that be cool. You go to the dentist for an X-Ray and they put some type of film inside your mouth (like they normally do), and a corresponding tape outside. Then they pull the tape apart and there that's your X-Ray. None of this putting the gun up to your head and running in the other room while they shoot you.

Third: This opens many kinds of questions (related to my first point). How are these X-Rays made and where else can we find them? How does this affect out daily life? Is this found in natural processes or only in synthetic processes (or processes involving synthetic material)? So...thoughts? (The paper is published in Nature)