What are the reasons X-ray vacuum tubes could not be replaced by solid state alternatives?
I'm thinking if it is possible to make a compact solid-state X-ray or higher energy photons generator just like how vacuum tube amplifiers, computers, etc. are going to be replaced by solid-state amplifiers, computers, etc. but not 100% replaced as we can still find vacuum tube amplifiers everywhere but vacuum tube computers are already very rare.
But if I have to form the reason why vacuum tubes are still used to generate high energy radiations instead of solid-state devices with my own reasoning (although I have very limited background in physics), high speed electrons are only possible if there is some kind of chamber inside. So, common sense tells us that there is a need to include a chamber inside that thing so electrons can move freely instead of flowing through solids that will pose many difficulties.