| Paper | Title | Page |
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| TUPGW023 | Incorporation of a MESA Linac Modules into BERLinPro | 1449 |
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Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin, grants of the Helmholtz Association and grants of Helmholtz Association and the DFG within GRK 2128 BERLinPro is an Energy Recovery Linac (ERL) project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is designed as - and for - experiments in accelerator physics and as a test bed for novel ERL components. MESA is an ERL project under construction at the Johannes Gutenberg-Universität, Mainz, Germany. MESA is designed as a user facility to perform experiments in dark matter physics and precision measurements of natural constants. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are described. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW023 | |
| About • | paper received ※ 30 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
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| WEPRB016 | Simulation of Quench Detection Algorithms for Helmholtz Zentrum Berlin SRF Cavities | 2834 |
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| The Helmholtz Zentrum Berlin is carrying out two accelerator projects which make use of high gradient SRF cavities: BERLinPro* and BESSY-VSR**. In both projects, a prompt detection of a quench is crucial to avoid damages in the cryomodules and cavities themselves. In this paper, the response of real time estimation of the cavity parameters*** using the transmitted and forward RF signals is simulated, in order to perform the quench detection. The time response of the estimated half bandwidth is compared with the dissipated power in the cavity walls for the different type of SRF cavities used in both projects, i.e., BERLinPro’s photoinjector, booster and linac, and BESSY-VSR 1.5 GHz and 1.75 GHz cavities. As an intermediate step prior to the implementation in an mTCA.4 system together with the LLRF control and test with a real cavity, the algorithm has been implemented using a National Instruments FPGA board to check the its proper behavior. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB016 | |
| About • | paper received ※ 16 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
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| WEPRB017 | Operational Experiences with X-Ray Tomography for SRF Cavity Shape and Surface Control | 2838 |
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| X-ray tomography has established as a non-destructive three-dimensional analysis tool, commercially offered by industrial vendors. Typical applications cover shape control and failure detection (voids, cracks) deep inside of complicated bulk pieces like engine blocks, bearings, turbine blades etc. We evaluated the applicability of the process for superconducting radio frequency cavities, in particular the 1.4-cell 1.3 GHz BERLinPro electron gun cavity and the 1.5 GHz single-cell VSR cavity prototype. The former experienced severe shape modifications during its tuning process and features a complicated internal stiffening construction. Thus it is a demanding challenge to measure its actual internal cavity surface shape after the complete preparation process with a resolution, sufficiently high (better than 0.2 mm) to serve as input for meaningful comparative field simulations. First tests with a vendor’s on-site X-ray source, operating at X-ray energies up to 590 keV revealed an insufficient resolution of the inner surface, attributed to the unfavorable X-ray damping characteristics of niobium. This was overcome with the aid of an accelerator-based source (X-ray spectrum up to 9 MeV), operated by Fraunhofer IIS, Fürth, Germany. Results both show significant, while understood, shape changes and indicate partial inner surface modifications of the gun cavity. Further the data evaluation process, which was needed to provide input for field simulations, raised issues because of the data set size and complexity, which are discussed in the paper. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB017 | |
| About • | paper received ※ 17 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |