Protons: Baseline and Alternatives, Studies Plan

Abstract

This paper focuses on the injector improvements and upgrades foreseen within the LHC Injectors Upgrade (LIU) project as well as the expected benefits in terms of proton beam characteristics resulting from their implementation. The roadmap of the main upgrades will be illustrated, with special emphasis on the machine studies and milestones during Run 2  that will have an impact on it. In this framework, a strategy to choose between scrubbing and a–C coating of the SPS will be also presented and discussed. Concerning the beams in  Run 2, we will not review here the possible physics production beams, which are the subject of [1], but rather some special LIU beams, like: 1) beams needed for electron cloud  enhancement and efficient LHC scrubbing (doublets); 2) extra–bright 25 ns beams produced with the pure batch compression scheme; 3) 8b+4e beams, which have the advantage of  allowing for higher bunch current while potentially reducing the electron cloud build up. Finally, the beam performances across the full injector chain will be estimated for the operation after Long Shutdown 2 (LS2).