They challenge the technology they are manufactured in because, to act as pixel detectors, they need to design devices to withstand irradiation from particle events. So they don't use your typical transistor design. In many ways it is a bit like a ccd you find in digital cameras but with a much finer sensitivity.
I continue to be impressed by the utility of the philosophical observation "If you want to know if anything truly exists, try hitting it really, really hard"
as for that bottle of hydrogen gas, they have one conspicuously labeled "PROTON SOURCE" in huge letters but thats actually a decoy, the real bottle of hydrogen is hidden and nondescript like most important things.