Once upon a time, I worked at a place that re-built linear accelerators.
Clinacs, Mevatrons, etc. Seeing the parts (assembling waveguides and hand making o-rings haunt my sleep to this day) still.
Those square blocks in the bottom (the aperture assembly) are depleted uranium. Imagine taking a flat file to one to take the dents (they are very soft) out on your first day.
I didn't stay long.