| Paper | Title | Other Keywords | Page |
|---|---|---|---|
| MOPMB029 | Exploring the Dynamics of Transverse Inter-Planar Coupling in the Superconducting Section of the PIP-II Linac | coupling, space-charge, linac, quadrupole | 155 |
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| This study investigates the crucial role that an accurate understanding of inter-planar coupling in the transverse plane plays in regulating charged particle dynamics in a high-intensity linear accelerator and minimizing foil/septum impacts during injection from the linac to a ring. We in-depth analyze the emergence and evolution of transverse inter-planar coupling through multiple active lattice elements, taking into account space charge and field nonlinearities in the superconducting section of the PIP-II linac. The article compares various analytical, numerical, and experimental techniques for measuring transverse coupling using beam and lattice matrices and provides insight into effective strategies for its mitigation prior to ring injectio | |||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB029 | ||
| About • | Received ※ 21 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 05 July 2023 | ||
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| MOPMB053 | Theoretical Study of Thin Noble-Metal Films on the Niobium Surface | niobium, interface, electron, experiment | 230 |
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Funding: The Center for Bright Beams, Supported by National Science Foundation award No. PHY-1549132 Recent experiments suggest that noble-metal deposition on niobium metal surfaces can remove the surface oxide and ultimately improve superconducting radio-frequency (SRF) cavities performance. In this preliminary study, we use density-functional theory to investigate the potential for noble-metal passivation of realistic, polycrystalline niobium surfaces for SRF. Specifically, we investigate the stability of gold and palladium monolayers on niobium surfaces with different crystal orientations and evaluate the impact of these impurities on superconducting properties. In particular, our results suggest that gold can grow in thin layers on the niobium surface, whereas palladium rather tends to dissolve into the niobium cavity. These results will help inform ongoing experimental efforts to passivate niobium surfaces of SRF cavities. |
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| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB053 | ||
| About • | Received ※ 22 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 19 August 2023 | ||
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| WEPWB001 | Preparation and Characterization of Nb Films Deposited in SRF Cavity via HiPIMS | cavity, SRF, niobium, site | 651 |
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| The RF performance of the niobium superconducting cavity has been continuously improved in recent 50 years. Since the maximum acceleration field (Eacc) has approached its theoretical limit, developing a more efficient and low-cost SRF cavity is one of the key challenges of the next generation particle accelerators. Niobium coated copper cavities are promising solutions because the SRF phenomenon occurrs within several hundred nanometers under the cavity surface. In literatures, the Nb coated Cu cavity prepared by direct current magnetron sputtering (DCMS) has serious Q-slope problem, which may be related to the low energy deposition. High power impulse magnetron sputtering (HiPIMS) can produce a high peak power and high ionization rate which may improve the thin film quality. Therefore, we prepared Nb coated Cu samples via HiPIMS on the 1.3 GHz dummy cavity at IHEP. | |||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB001 | ||
| About • | Received ※ 15 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 19 August 2023 — Issue date ※ 20 August 2023 | ||
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| WEPWB084 | The Interaction among Interstitial C/N/O/H and Vacancy in Niobium via First-Principles Calculation | niobium, electron, site, cavity | 778 |
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| We calculate the interaction among zero dimensional defects in niobium lattice through first-principles calculation. And we compare the trapping effect of hydrogen among carbon, nitrogen, and oxygen as well as the trapping effect of interstitial atoms by vacancy. We find that the interstitial C/N/O have similar effect of trapping interstitial hydrogen in niobium lattice, and the vacancy can trap interstitial C/N/O/H in adjacent protocells and strengthen their chemical bond with Nb. These calculations give some explanation for improving superconducting performance of niobium cavities through medium temperature baking. | |||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB084 | ||
| About • | Received ※ 15 June 2023 — Revised ※ 25 June 2023 — Accepted ※ 29 June 2023 — Issue date ※ 03 July 2023 | ||
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