1–6 Jun 2025
Taipei International Convention Center (TICC)
Asia/Taipei timezone

Bunch length regulation in the LHC during controlled emittance blow-up

WEPS018
4 Jun 2025, 16:00
2h
Exhibiton Hall A _Salmon (TWTC)

Exhibiton Hall A _Salmon

TWTC

Poster Presentation MC5.D09 Emittance manipulation, Bunch Compression and Cooling Wednesday Poster Session

Speaker

Niki Gallou (European Organization for Nuclear Research)

Description

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.

Region represented Europe
Paper preparation format LaTeX

Author

Niki Gallou (European Organization for Nuclear Research)

Co-authors

Bartosz Przemyslaw Bielawski (European Organization for Nuclear Research) Helga Timko (European Organization for Nuclear Research) Michael Jaussi (European Organization for Nuclear Research)

Presentation materials

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