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MO3B2 |
Beam Dynamics Using Superconducting Passive Harmonic Cavities with High Current per Bunch |
cavity, synchrotron, impedance, emittance |
14 |
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- A. Gamelin, V. Gubaidulin, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France
- N. Yamamoto
KEK, Ibaraki, Japan
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In 4th generation synchrotron light sources, harmonic cavities (HCs) are critical components needed to achieve the required performance. They provide longer bunches, which helps to reduce statistical effects (intra-beam scattering and Touschek effect). In "timing" modes, where the bunch spacing is larger than in conventional modes and the number of particles per bunch is higher, this need is even greater. In this article, we present the beam dynamics in the high current per bunch regime and how it interacts with the single bunch collective effects. In particular, a dipole-quadrupole instability is observed above the microwave threshold and a coupling between the dipole and cavity modes is shown to limit bunch lengthening at low current. The effective gain from the use of HCs in terms of lifetime, emittance, and energy spread is also discussed.
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Slides MO3B2 [1.529 MB]
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DOI • |
reference for this paper
※ doi:10.18429/JACoW-FLS2023-MO3B2
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About • |
Received ※ 13 August 2023 — Revised ※ 15 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023 |
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MO3B4 |
Generating High Repetition Rate X-ray Attosecond Pulses in SAPS |
radiation, storage-ring, laser, electron |
22 |
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- W. Liu, X. Liu, Y. Zhao
IHEP CSNS, Guangdong Province, People’s Republic of China
- Y. Jiao, X. Li, S. Wang
IHEP, Beijing, People’s Republic of China
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Attosecond, which refers to 10-18 seconds, is the timescale of electron motion within an atom. Accurate observation of electron motion helps deepen the understanding of microscopic quantum processes such as charge transfer in molecules, wave packet dynamics, and charge transfer in organic photovoltaic materials. To meet the needs of relevant research, the South Advanced Photon Source (SAPS), currently in the design phase, is considering the construction of an attosecond beamline. This paper presents relevant research on achieving high-repetition-rate coherent attosecond pulses on the fourth-generation storage ring at SAPS. Realizing attosecond pulses in a storage ring requires femtosecond to sub-femtosecond-level longitudinal modulation of the beam, and the modulation scheme needs to consider multiple factors to avoid a significant impact on other users. The study shows that with high-power, few-cycle lasers, and advanced beam modulation techniques, the photon flux of attosecond pulses can be significantly enhanced with a minimal impact on the brightness of synchrotron radiation. Adopting high-repetition-rate lasers and precise time delay control, the repetition rate of attosecond pulses at SAPS can reach the megahertz level. Currently, the design wavelength range for attosecond pulses covers the water window (2.3-4.4 nm), which is "transparent" to water but strongly absorbed by elements constituting living organisms. This wavelength range has significant application value in fields such as biology and chemistry.
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Slides MO3B4 [3.400 MB]
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DOI • |
reference for this paper
※ doi:10.18429/JACoW-FLS2023-MO3B4
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About • |
Received ※ 23 August 2023 — Revised ※ 24 August 2023 — Accepted ※ 31 August 2023 — Issued ※ 02 December 2023 |
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WE4P18 |
Preliminary Design of Higher-order Achromat Lattice for the Upgrade of the Taiwan Photon Source |
lattice, emittance, storage-ring, radiation |
184 |
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- N.Y. Huang, M.-S. Chiu, P.J. Chou, G.-H. Luo, H.W. Luo, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan
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We study the upgrade of Taiwan Photon Source (TPS) with energy saving as the prime objective. The upgrade design is dubbed TPS-II. To accommodate the constraints imposed by the existing TPS tunnel, we choose the higher-order achromat (HOA) lattice configuration which is composed of the 5BA and 4BA cells. This HOA lattice produces a natural beam emittance about 131 pm-rad for a 3 GeV, 518.4 m storage ring. The on-momentum dynamic aperture is about 8 mm and the estimated Touschek life time reaches around 5.7 hours at total beam current of 500 mA. As a result of the ultralow beam emittance, the brightness and coherence fraction (CF) of the photon beam are improved with a factor of several tens especially in the photon wavelength around 0.1 nm. The challenges and preliminary results of this HOA lattice design will be presented.
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Poster WE4P18 [5.398 MB]
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DOI • |
reference for this paper
※ doi:10.18429/JACoW-FLS2023-WE4P18
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About • |
Received ※ 21 August 2023 — Revised ※ 28 August 2023 — Accepted ※ 30 August 2023 — Issued ※ 02 December 2023 |
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reference for this paper using
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※ LaTeX,
※ Text/Word,
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