IBIC2020 - List of Authors (Alves, D.)

Paper	Title	Page
WEPP27	An Alternative Processing Algorithm for the Tune Measurement System in the LHC	162
	L. Grech, D. Alves, M. Gąsior, S. Jackson, O.R. Jones, T.E. Levens, J. Wenninger CERN, Geneva, Switzerland G. Valentino University of Malta, Information and Communication Technology, Msida, Malta
	The betatron tune in the Large Hadron Collider (LHC) is measured using a Base-Band-Tune (BBQ) system. Processing of these BBQ signals is often perturbed by 50Hz noise harmonics present in the beam. This causes the tune measurement algorithm, currently based on peak detection, to provide incorrect tune estimates during the acceleration cycle with values that clearly oscillate between neighbouring harmonics. The LHC tune feedback cannot be used to its full extent in these conditions as it relies on stable and reliable tune estimates. In this work we present two alternative tune measurement algorithms, designed to mitigate this problem by ignoring small frequency bands around the 50Hz harmonics and estimating the tune from spectra with gaps. One is based on Gaussian Processes and the other is based on a weighted moving average. We compare the tune estimates of the new and present algorithms and put forward a proposal that can be implemented during the renovation of the BBQ system for the next physics run of the LHC.
	Poster WEPP27 [1.564 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2020-WEPP27
About •	paper received ※ 02 September 2020 paper accepted ※ 18 September 2020 issue date ※ 30 October 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

An Alternative Processing Algorithm for the Tune Measurement System in the LHC

162

L. Grech, D. Alves, M. Gąsior, S. Jackson, O.R. Jones, T.E. Levens, J. Wenninger
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The betatron tune in the Large Hadron Collider (LHC) is measured using a Base-Band-Tune (BBQ) system. Processing of these BBQ signals is often perturbed by 50Hz noise harmonics present in the beam. This causes the tune measurement algorithm, currently based on peak detection, to provide incorrect tune estimates during the acceleration cycle with values that clearly oscillate between neighbouring harmonics. The LHC tune feedback cannot be used to its full extent in these conditions as it relies on stable and reliable tune estimates. In this work we present two alternative tune measurement algorithms, designed to mitigate this problem by ignoring small frequency bands around the 50Hz harmonics and estimating the tune from spectra with gaps. One is based on Gaussian Processes and the other is based on a weighted moving average. We compare the tune estimates of the new and present algorithms and put forward a proposal that can be implemented during the renovation of the BBQ system for the next physics run of the LHC.

Poster WEPP27 [1.564 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2020-WEPP27

About •

paper received ※ 02 September 2020 paper accepted ※ 18 September 2020 issue date ※ 30 October 2020

Export •

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