Chapter 13: Vacuum technology

It is easy to forget that the transformational discoveries made by terrestrial gravitational-wave detectors depended, first of all, on ignoring the effects of Earth’s atmosphere on the instruments. This tacit (but so far, accurate) assumption is perhaps a tribute to the innovative engineering embodied in vacuum systems enclosing current interferometric detectors. Here, we will revisit the fundamental interactions at the root of vacuum requirements, examine different solutions proposed and implemented so far, and consider the implications for larger and more sensitive future instruments.