Incoherent Beam-Beam Effects and Lifetime Optimisation

In 2017, three major developments with important implications on the beam lifetime took place: the deployment of the crossing angle orchestration (allowing to act on it even in stable beams), the reduction of β * from 40 to 30 cm and the switch to 8b4e (and later BCS) beams. These actions have been closely followed up with Dynamic Aperture (DA) simulations and, when possible, also Machine Developments (MDs), aiming at maintaining the beam lifetime on the optimum for the luminosity production. The fill-by-fill follow-up was enabled by new tools for the LHC performance analysis based on modelling and measurements. While the predictions of the machine settings massively rely on CERN's computing resources, the performance analysis requires inputs from several instruments; the difficulties encountered in both cases will be presented together with recommendations for the future.