| Paper | Title | Page |
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MOPB009 |
Harmonic cavity dynamics studies: efficient methods and new type of Robinson instabilities | |
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| In order to cope with the intrabeam scattering effect induced emittance growth, the Touschek scattering effect induced beam lifetime limitation and the beam-impedance coupling effect induced instability growth, harmonic cavities are used to stretch the bunch and provide Landau damping, which has become a necessary choice for modern advanced synchrotron light sources. However, harmonic cavities operated in bunch lengthening mode can cause some adverse effects such as beam loading, Robinson instability, etc., which possibly pose a limitation on the maximum bunch lengthening. This paper will report on our research progress on harmonic cavity dynamics associated with efficient methods for bunch lengthening calculation and new type of Robinson instabilities. | ||
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| MOPB010 | Impact of NEG Coating Thickness and Resistivity on Beam Coupling Impedance | 30 |
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| In diffraction-limited storage rings, non-evaporable getter (NEG) coatings are generally used to assure the ultrahigh vacuum, which, however, also increase the beam coupling impedance that can affect beam dynamics. Ignoring the influence of coating roughness, the impact of NEG coatings on the impedance mainly depends on the coating thickness and resistivity. In this paper, we investigate the impedance characteristics of a round CuCrZr vacuum chamber coated by NEG with different thickness and resistivity. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB010 | |
| About • | Received ※ 29 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 12 August 2024 | |
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| MOPB017 | Analysis of the Fluctuation of Resonance Driving Terms for Nonlinear Lattice Optimization | 41 |
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| Minimizing resonance driving terms (RDTs) of nonlinear magnets is a traditional approach to enlarge the dynamic aperture (DA) of a storage ring. The local cancellation of nonlinear dynamics, which is adopted by some diffraction-limited storage rings, is more effective than the global cancellation. The former has smaller fluctuation of RDTs along the ring. In this paper, the correlation between two kinds of RDT fluctuations is found. The qualitative analysis shows that minimizing the RDT fluctuations is beneficial for controlling the crossing terms and thus enlarging the DA. This qualitative analysis is supported by the statistical analysis of nonlinear solutions of a double-bend achromat lattice. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB017 | |
| About • | Received ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 11 April 2024 | |
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