Speaker
Description
Recent studies showed that the broadband impedance in synchrotrons can significantly alter the longitudinal multi-bunch instability threshold. The results of the beam-based impedance measurement campaign in the Large Hadron Collider (LHC) reveal a discrepancy with predictions based on the present impedance model. A larger imaginary impedance with a lower roll-off frequency would reproduce the observations. Since the impedance will be impacted by the High-Luminosity (HL) LHC upgrades, longitudinal beam stability needs to be carefully re-evaluated. This contribution discusses the outcome of the semi-analytical analysis for the HL-LHC parameters together with the updated broadband impedance model. Future benchmark measurements are proposed to probe the multi-bunch instability threshold driven by the partially compensated main RF cavity impedance. Finally, possible mitigation measures to increase the instability threshold are discussed.
Funding Agency
Research supported by the HL-LHC project
| In which format do you inted to submit your paper? | LaTeX |
|---|---|
| Preprint marking on your proceeding paper | I wish my paper to be marked as preprint. |
| I no longer wish to present this contribution, please withdraw it. | Keep my contribution |