Optics Studies and Corrections in the LHC

This report presents three optics studies conducted during an internship with the Optics Measurement and Correction team at CERN’s Large Hadron Collider (LHC), aimed at improving machine performance and luminosity delivery. The first study involved commissioning of ion optics for the upcoming proton and oxygen collision cycles, using AC dipole–based measurements and global optics corrections to reduce $\beta$-beating. The second study examined waist shifts and $\beta^*$-beating at \qty{18}{cm} optics following application of optics corrections during LHC commissioning, revealing significant discrepancies between measured and simulated optics at low $\beta^*$, which suggests limitations in current models. The third study investigated anomalies in 3Qy resonance driving term measurements, identifying strong evidence for systematic miscalibration of the beam position monitors as a potential cause. By combining LHC measurements with MAD-X and Xsuite simulations, these studies provide valuable insights relevant to both near-term runs and long-term upgrades, including the High Luminosity LHC.