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| URL | https://doi.org/10.18429/JACoW-IPAC2025-WEPS018 |
|---|---|
| Title | Bunch length regulation in the LHC during controlled emittance blow-up |
| Authors |
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| Abstract | Controlled longitudinal emittance blow-up is indispensable for the operation of the Large Hadron Collider (LHC) to counteract single-bunch loss of Landau damping during the acceleration ramp. The blow-up is performed by injecting RF phase noise in a narrow frequency band into the beam phase loop, with bunch-length feedback regulating the noise amplitude. In 2024, the variation of the bunch length due to imperfect regulation caused unacceptable beam-induced heating of certain accelerator components. In this contribution, we present the results of extensive simulation scans that have been used to optimize the feedback parameters. We show how this optimization, along with a reduction of the feedback delay on the controls side, has been implemented in the LHC and significantly improved the bunch length evolution during acceleration. Finally, we discuss the results of a measurement scan performed during an operational period of five weeks to fine-tune the blow-up feedback settings. |
| Paper | download: WEPS018.pdf |
| Cite | BibTeX, LaTeX, Text/Word, RIS, EndNote |
| Conference | 16th International Particle Accelerator Conference |
| Series | |
| Location | Taipei, Taiwan |
| Date | 01-06 Jun 2025 |
| Publisher | JACoW Publishing, Geneva, Switzerland |
| Editorial Board | * Ming-Chyuan Lin - National Synchrotron Radiation Research Center * Yoichi Sato - KEK * Jui-Che Huang - National Synchrotron Radiation Research Center * David Button - Australian Nuclear Science and Technology Organisation * Ping-Shun Chuang - National Synchrotron Radiation Research Center |
| Online ISBN | 978-3-95450-248-6 |
| Online ISSN | 2673-5490 |
| Received | 26 May 2025 |
| Revised | 30 May 2025 |
| Accepted | 01 June 2025 |
| Issued | 05 November 2025 |
| DOI | 10.18429/JACoW-IPAC2025-WEPS018 |
| Pages | 2279-2282 |
| Copyright | Published by JACoW Publishing under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI. |