a DIY portable X-Ray Fluorescence spectrometer + analyzer that does instant elemental analysis
Start with a tape dispenser, I've heard that they emit X-Rays ;)
this is fact, I saw a paper on it a while ago. I doubt it's an intense enough source though. and it has to be done under vacuum
I might have smuggled in the video after you read and commented on this, but only by accident.
I worked on XRFs a lot last year. Not handheld ones though, but benchtops and some really really big ones. It will be cool to see where this project goes.
Many of the parts required are easily available from Amptek and Newton Scientific if you have the funds. Still considerably cheaper than finished commercial products. Here is a kit from Amptek that can be built. http://amptek.com/products/complete-xrf-experimenters-kit/