Development of new ion beams at the CERN ion injector complex for future physics programmes

Abstract The heavy-ion physics programme at CERN relies on lead ion beams. In recent years, interest in conducting experiments with nuclei lighter than lead has grown significantly. Before new ion species can be considered operational for experiments, their feasibility for production and acceleration throughout the accelerator complex must be assessed. Several ion species have been tested in the past: argon and xenon were delivered for NA61/SHINE physics in 2015 and 2017, with xenon also reaching the LHC in 2017. More recent tests in the CERN accelerator complex include oxygen in 2023, in preparation for an LHC oxygen run in 2025; krypton, as a candidate for HL-LHC in Run 5 (2036-2041); and magnesium in 2024, requested by NA61/SHINE, an SPS North Area fixed target experiment. A boron test for the NA61/SHINE is planned during Long Shutdown 3 (2026-2029). This contribution reviews the performance of the ion complex with recent oxygen and magnesium beam tests and future plans for developing new ion species.