Beam Diagnostic Challenges for High Energy Hadron Colliders

Two high energy hadron colliders are currently in the operational phase of their life-cycle, RHIC and LHC. A major upgrade of the LHC, HL-LHC, planned for 2023 aims at accumulating ten times the design integrated luminosity by 2035. Still further in the future, studies of SppC and FCC are investigating machines with a center-of-mass energy of up to 100 TeV and up to 100 km circumference. The existing machines pose considerable diagnostic challenges, which will become even more critical with any increase in size and energy. Cryogenic environments lead to additional difficulties for diagnostics and further limit the applicability of intercepting devices, making non-invasive profile and halo measurements essential. The sheer size of these colliders requires the use of radiation tolerant read-out electronics in the tunnel and low noise, low loss signal transmission. It also implies a very large number of beam position and loss monitors, all of which have to be highly reliable. To fully understand the machine and tackle beam instabilities bunch-by-bunch measurements become increasingly important for all diagnostic systems. This contribution discusses current developments in the field.