Paper | Title | Other Keywords | Page |
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MOPOST022 | Upgrade of the Radio Frequency Quadrupole of the ReAccelerator at NSCL/FRIB | rfq, operation, vacuum, MMI | 104 |
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Funding: Work supported by the National Science Foundation under grant PHY15-65546 The ReA-RFQ is a four-rod room-temperature structure aimed to be the first step acceleration of rare isotopes as well as stable beams before injection into the ReA SRF linac. The beams of charge to mass ratios of 1/5 to 1/2 from the Electron Beam Ion Trap at 12 keV/u should be accelerated to at least 500 keV/u to be efficiently accelerated in the main SRF linac. Since the commissioning of the original ReA RFQ in 2010 the design voltage has never been reached, and CW operation was never achieved due to cooling issues. In 2016 a new design including trapezoidal modulation was proposed, which permitted achieving increased reliability, and would allow reaching the original required specifications. The proposed new rods were built and installed in 2019 and commissioned in the same year. Since then, the RFQ has been working very successfully. Recently it was opened for inspection and verification of its internal status. No damage and discoloration were observed. This contribution will describe the RFQ rebuild process, involving specific RF protections and other technical aspects related to the assembly of the structure. Results of the operation with a variety of beams will be presented. |
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DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST022 | ||
About • | Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 11 July 2022 | ||
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
THPOST020 | Visualisation of Pareto Optimal Spaces and Optimisation Solution Selection Using Parallel Coordinate Plots | cavity, impedance, GUI, ECR | 2487 |
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In this paper, we build on previous work where multi-objective genetic algorithms were used to optimise RF cavities using non-uniform rational basis splines (NURBS) to improve the cavity geometries and reduce peak fields. These optimisations can produce thousands of Pareto optimal solutions, from which a final cavity solution must be selected based on design criteria, such as accelerating gradient and power requirements. As all points are considered equally optimal, this can prove difficult without further analysis. Here we focus on the visualisation of the Pareto optimal points and the final solution selection process. We have found that the use of clustering algorithms and parallel coordinate plots (PCPs) provide the best way to represent the data and perform the necessary trade-offs between the peak fields and shunt impedance required to pick a final design. | |||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST020 | ||
About • | Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022 | ||
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||