Sextupole RDTs in the LHC at injection and in the ramp

During 2023, examination of the action dependence of sextupolar resonance driving terms (RDT) in the LHC at injection, as measured with an AC-dipole, demonstrated that a robust measurement of the RDTs could still be achieved even with very small amplitude kicks, typically used for linear optics stud...

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Bibliographic Details
Main Authors: Horney, S, Maclean, E, Burrows, P, Carlier, F, Dilly, J, Ferrentino, V, Deniau, L, Fol, E, Le Garrec, M, Keintzel, J, Hofer, M, Persson, T, van Riesen-Haupt, L, Wegscheider, A, Soubelet, F, Tomás, R
Format: Conference item
Language:English
Published: JACoW Publishing 2024
Description
Summary:During 2023, examination of the action dependence of sextupolar resonance driving terms (RDT) in the LHC at injection, as measured with an AC-dipole, demonstrated that a robust measurement of the RDTs could still be achieved even with very small amplitude kicks, typically used for linear optics studies. Consequently, analysis of optics measurements from 2022 to 2024 during the LHC energy ramp allowed a first measurement of the sextupole resonance evolution. A large asymmetry was observed between the two LHC beams, with the clockwise circulating beam (LHCB1) being significantly worse than the counter-clockwise circulating beam (LHCB2), and a clear increase in the RDT strength during the ramp was observed. During 2024 commissioning, a first attempt was made to correct the 𝑓1020 RDT of LHCB1 at injection. Results are presented in this report.