Concept of beam-related machine protection for the Future Circular Collider

In the Future Circular Collider (FCC) study, a proton-proton circular collider (FCC-hh) is considered with a stored beam energy 20 times higher than that of the LHC. Any uncontrolled release of such energy could potentially result in severe damage to the accelerator components. Machine protection of the FCC-hh is hence very important and challenging. With a machine-protection strategy similar to the LHC, FCC would require up to three turns to dump the beam synchronously after a failure detection. Due to several possible ultrafast failures, which could lead to significant beam losses in a few turns, it is important to further reduce the reaction time of the machine protection system (MPS) for the FCC. Reducing the detection time of a failure by using faster beam monitors, e.g. diamond detectors, can reduce the time between a beam loss and the beam dump request. Communication delay of the interlock system to the beam dumping system can be reduced by using a more direct signal path. More than one beam-free abort gap will shorten the time required for the synchronization between the abort gap and the extraction kicker. Different failure scenarios are classified according to the speed of the failure onset and the subsequent increase of induced beam losses. The critical failure modes, their potential mitigations and impacts on the design of the MPS are presented.