ICALEPCS2023 - List of Authors (Bruchon, N.)

Paper	Title	Page
TUPDP086	Operational Tool for Automatic Setup of Controlled Longitudinal Emittance Blow-Up in the CERN SPS	723
	N. Bruchon, I. Karpov, N. Madysa, G. Papotti, D. Quartullo CERN, Meyrin, Switzerland
	The controlled longitudinal emittance blow-up is necessary to ensure the stability of high-intensity LHC-type beams in the CERN SPS. It consists of diffusing the particles in the bunch core by injecting a bandwidth-limited noise into the beam phase loop of the main 200 MHz RF system. Obtaining the correct amplitude and bandwidth of this noise signal is non-trivial, and it may be tedious and time-demanding if done manually. An automatic approach was developed to speed up the determination of optimal settings. The problem complexity is reduced by splitting the blow-up into multiple sub-intervals for which the noise parameters are optimized by observing the longitudinal profiles at the end of each sub-interval. The derived bunch lengths are used to determine the objective function which measures the error with respect to the requirements. The sub-intervals are tackled sequentially. The optimization moves to the next one only when the previous sub-interval is completed. The proposed tool is integrated into the CERN generic optimization framework that features pre-implemented optimization algorithms. Both single- and multi-bunch high-intensity beams are quickly and efficiently stabilized by the optimizer, used so far in high-intensity studies. A possible extension to Bayesian optimization is being investigated.
DOI •	reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-TUPDP086
About •	Received ※ 05 October 2023 — Accepted ※ 11 December 2023 — Issued ※ 19 December 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Operational Tool for Automatic Setup of Controlled Longitudinal Emittance Blow-Up in the CERN SPS

723

N. Bruchon, I. Karpov, N. Madysa, G. Papotti, D. Quartullo
CERN, Meyrin, Switzerland

The controlled longitudinal emittance blow-up is necessary to ensure the stability of high-intensity LHC-type beams in the CERN SPS. It consists of diffusing the particles in the bunch core by injecting a bandwidth-limited noise into the beam phase loop of the main 200 MHz RF system. Obtaining the correct amplitude and bandwidth of this noise signal is non-trivial, and it may be tedious and time-demanding if done manually. An automatic approach was developed to speed up the determination of optimal settings. The problem complexity is reduced by splitting the blow-up into multiple sub-intervals for which the noise parameters are optimized by observing the longitudinal profiles at the end of each sub-interval. The derived bunch lengths are used to determine the objective function which measures the error with respect to the requirements. The sub-intervals are tackled sequentially. The optimization moves to the next one only when the previous sub-interval is completed. The proposed tool is integrated into the CERN generic optimization framework that features pre-implemented optimization algorithms. Both single- and multi-bunch high-intensity beams are quickly and efficiently stabilized by the optimizer, used so far in high-intensity studies. A possible extension to Bayesian optimization is being investigated.

DOI •

reference for this paper ※ doi:10.18429/JACoW-ICALEPCS2023-TUPDP086

About •

Received ※ 05 October 2023 — Accepted ※ 11 December 2023 — Issued ※ 19 December 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)