HB2023 - Table of Session: WEA1C (Contributed Presentations WG A)

Paper	Title	Page
WEA1C1	Bunch-by-bunch Tune Shift Studies for LHC-type Beams in the CERN SPS	194
	I. Mases Solé, H. Bartosik, K. Paraschou, M. Schenk, C. Zannini CERN, Meyrin, Switzerland
	After the implementation of major upgrades as part of the LHC Injector Upgrade Project (LIU), the Super Proton Synchrotron (SPS) delivers high intensity bunch trains with 25 ns bunch spacing to the Large Hadron Collider (LHC). These beams are exposed to several collective effects in the SPS, such as beam coupling impedance, space charge and electron cloud, leading to relatively large bunch-by-bunch coherent and incoherent tune shifts. Tune correction to the nominal values at injection is crucial to ensure beam stability and good beam transmission. Measurements of the bunch-by-bunch coherent tune shifts have been performed under different beam conditions. In this paper, we present the measurements of the bunch-by-bunch tune shift as function of bunch intensity for trains of 72 bunches. The experimental data are compared to multiparticle tracking simulations (including other beam variants such as 8b4e beam and hybrid beams) using the SPS impedance model.
	Slides WEA1C1 [2.613 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA1C1
About •	Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 09 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA1C2	Design of a Proof-of-Principle Experiment for the DLMN Method to Identify Magnetic Field Errors
	C. Caliari TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim, A. Oeftiger GSI, Darmstadt, Germany
	Magnetic field errors limit the beam intensity in synchrotrons as they excite nonsystematic resonances, reduce dynamic aperture, and may result in beam loss due to space charge induced resonance crossing. Methods to establish a field error model from beam-based measurements are therefore a valuable tool for realistic limitation and improvement studies. We report on the implementation of a proof-of-principle experiment in the GSI synchrotron SIS18 to identify both linear and non-linear field errors. The goal is to demonstrate the Deep Lie Map Network (DLMN) technique, a proposed data-driven approach based on (unstructured) turn-by-turn BPM data. Established identification procedures in the literature are based on orbit or tune response matrices, or resonance driving terms. While they sequentially build a field error model for subsequent accelerator sections, the DLMN approach could save valuable beam time by detecting field errors in parallel. We underline the potential of the DLMN method via detailed simulation studies to infer gradient and sextupole errors. The outline of a proof-of-principle experiment is discussed upon first experimental experience.
	Slides WEA1C2 [1.439 MB]
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Bunch-by-bunch Tune Shift Studies for LHC-type Beams in the CERN SPS

194

I. Mases Solé, H. Bartosik, K. Paraschou, M. Schenk, C. Zannini
CERN, Meyrin, Switzerland

After the implementation of major upgrades as part of the LHC Injector Upgrade Project (LIU), the Super Proton Synchrotron (SPS) delivers high intensity bunch trains with 25 ns bunch spacing to the Large Hadron Collider (LHC). These beams are exposed to several collective effects in the SPS, such as beam coupling impedance, space charge and electron cloud, leading to relatively large bunch-by-bunch coherent and incoherent tune shifts. Tune correction to the nominal values at injection is crucial to ensure beam stability and good beam transmission. Measurements of the bunch-by-bunch coherent tune shifts have been performed under different beam conditions. In this paper, we present the measurements of the bunch-by-bunch tune shift as function of bunch intensity for trains of 72 bunches. The experimental data are compared to multiparticle tracking simulations (including other beam variants such as 8b4e beam and hybrid beams) using the SPS impedance model.

Slides WEA1C1 [2.613 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA1C1

About •

Received ※ 29 September 2023 — Revised ※ 08 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 09 October 2023

Cite •

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

WEA1C2

Design of a Proof-of-Principle Experiment for the DLMN Method to Identify Magnetic Field Errors

C. Caliari
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim, A. Oeftiger
GSI, Darmstadt, Germany

Magnetic field errors limit the beam intensity in synchrotrons as they excite nonsystematic resonances, reduce dynamic aperture, and may result in beam loss due to space charge induced resonance crossing. Methods to establish a field error model from beam-based measurements are therefore a valuable tool for realistic limitation and improvement studies. We report on the implementation of a proof-of-principle experiment in the GSI synchrotron SIS18 to identify both linear and non-linear field errors. The goal is to demonstrate the Deep Lie Map Network (DLMN) technique, a proposed data-driven approach based on (unstructured) turn-by-turn BPM data. Established identification procedures in the literature are based on orbit or tune response matrices, or resonance driving terms. While they sequentially build a field error model for subsequent accelerator sections, the DLMN approach could save valuable beam time by detecting field errors in parallel. We underline the potential of the DLMN method via detailed simulation studies to infer gradient and sextupole errors. The outline of a proof-of-principle experiment is discussed upon first experimental experience.

Slides WEA1C2 [1.439 MB]

Cite •

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