Sextupole RDTs in the LHC at injection and in the ramp
Proceedings of the 15th International Particle Accelerator Conference (IPAC 2024) JACoW Publishing (2024) 71-74
Authors:
Sasha Horney, Philip Burrows
Abstract:
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.
