LHC Injectors Upgrade project: Towards new territory beam parameters

The LHC Injectors Upgrade (LIU) project aims at increasing the intensity and brightness in the LHC injectors in order to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring high availability and reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2035). This requires extensive hardware modifications and new beam dynamics solutions in the entire LHC proton and ion injection chains: the new Linac4, the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS), the Super Proton Synchrotron (SPS), together with the ion PS injectors (the Linac3 and the Low Energy Ion Ring (LEIR)). All hardware modifications will be implemented during the 2019-2020 CERN accelerators shutdown. This paper will analyze the various project phases, share the lessons learned, and conclude on the expected beam parameter reach, together with the risks.