Estimated LHC RF system performance reach at injection during Run III and beyond

This note describes the performance limitations of the present LHC RF system on the injection plateau, in view of increased intensities in Run III and in the HL-LHC era. The minimum required injection voltage is derived from beam dynamics constraints and operational experience. The maximum available voltage is given by beam measurements with the half-detuning beam-loading compensation scheme. From these two constraints, the performance reach with increased intensities is evaluated. Various studies, such as a potential RF upgrade, or alternative beam-loading compensation scenarios, are recommended.