1 word. Triboelectrification.
Apparently a piece of sellotape being pulled from its backing in a vacuum chamber can release 15KeV X Rays.
I have no f**king clue how that works but DARPA funded a project and it's apparently the basis of the SoA in hand held Xray flourescence metal analysers.
So there are other ways to make Xrays (or if you're into chip lithography Xtreme UV) other than the classic than banging electrons into lumps of metal (AKA Coolidge Tube) and plasma's (which turn out to only be good for "soft" Xrays into the 100s of eV's.
Biting the hand that feeds IT
