Speaker
Description
One of the main drivers of integrated luminosity production in the High-Luminosity LHC (HL-LHC) era is the bunch intensity, expected to reach $2.3\times10^{11}$~protons per bunch at injection compared to the maximum $1.8\times10^{11}$ achieved in Run~3 operation. Such high intensities bring significant challenges, in particular localized beam induced heating due to impedance and the associated risk of equipment damage. In that respect, any issue discovered only in Run~4, the first run of the HL-LHC era, could lead to significant downtime or intensity limitations until appropriate mitigation measures are put in place. It is therefore essential to identify such potential limitations to achieve the target intensity before the end of the presently ongoing Run~3. This paper summarizes the preparation steps and strategy foreseen for dedicated high-intensity tests at the end of the 2026 LHC operation, as a last step before Long Shutdown~3 (LS3). The tests aim at reaching and sustaining HL-LHC beam parameters with various HL-LHC beam types, in order to probe impedance-related limits and assess equipment non-conformities, as well as potential design issues and unknown limitations in view of reliable HL-LHC operation. Preparation for the high-intensity tests started with dedicated machine development studies in 2025, making significant progress towards HL-LHC beams and identifying critical devices. Key observations and plans for 2026 are presented.
| Paper status | Resubmitted proceeding files received and assigned to an editor. Accepted. |
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