| Internal Note | |
| Report number | CERN-ACC-NOTE-2021-0008 |
| Title | LHC 3324: Counteracting coupling decay at injection, |
| Author(s) | Persson, Tobias Hakan Bjorn (CERN) ; Maclean, Ewen Hamish (CERN) ; Hulpers, Fredrik ; Solfaroli Camillocci, Matteo (CERN) ; Hofer, Michael (CERN) ; Tomas Garcia, Rogelio (CERN) ; Garcia-Tabares Valdivieso, Ana (Universidad Complutense (ES)) |
| Corporate author(s) | CERN. Geneva. ATS Department |
| Publication | 2021 |
| Imprint | 22 Feb 2021 |
| Number of pages | 22 |
| Subject category | Accelerators and Storage Rings |
| Accelerator/Facility, Experiment | CERN LHC |
| Keywords | LHC ; Optics ; Coupling ; MCS |
| Abstract | The b3 spool-pieces are corrector sextupole magnets (MCS), are designed to correct the b3-error of the main dipoles. Changes in the settings of the MCS have been linked to changes in transverse coupling. This implies that there is a nonzero vertical orbit in the MCS which is feeding down to coupling. In this report we investigate if this is likely to be an effect of a non-centered orbit or if the MCS are misaligned with respect to the main dipole. The results indicate that the misalignments of the MCS are the dominant cause. A method to change the powering of the MCS in order to compensate for the chomaticity decay but without changing the global coupling is also tested and reported. |
| Submitted by | alessia.valenza@cern.ch |
Record created 2021-03-08, last modified 2021-08-06
