Paper | Title | Other Keywords | Page |
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SUPFDV012 | The Development of HiPIMS Multilayer SIS Film Coatings on Copper for SRF Applications | site, cavity, SRF, lattice | 86 |
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Funding: Authors acknowledge both the EASITrain, Marie Sklodowska-Curie Action (MSCA) Innovative Training Network (ITN), Grant Agreement no. 764879 and the ARIES collaboration, Grant Agreement no. 730871 In recent years, the use of alternatives to bulk Nb in the fabrication of SRF cavities, including novel materials and/or fabrication techniques, have been extensively explored by the SRF community. One of these new methodologies is the use of a superconductor-insulator-superconductor (SIS) multilayer structure. Typically, these have been envisaged for use with bulk Nb cavities. However, it is conceivable to combine the benefits of SIS structures with the benefits of coated Cu cavities. It is also clear that the use of energetic deposition techniques such as high power impulse magnetron sputtering (HiPIMS), provide significant benefits over typical DC magnetron sputtering (MS) coatings, in terms of SRF performance. In light of this, two series of multilayer SIS film coatings, with a Nb-AlN-NbN structure, were deposited onto electropolished OFHC Cu samples, with the use of HiPIMS, in order to determine the efficacy of this approach. This contribution details the development of these coatings and the required optimization of the coating parameters of the separate material systems, through the use of multiple material and superconducting characterization techniques. |
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Poster SUPFDV012 [2.061 MB] | ||
DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPFDV012 | ||
About • | Received ※ 20 June 2021 — Accepted ※ 21 December 2021 — Issue date ※ 27 April 2022 | ||
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SUPTEV009 | Development of a New B-Mapping System for SRF Cavity Vertical Tests | cavity, SRF, background, radiation | 137 |
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Funding: This work was supported by the Helmholtz Association within the topic Accelerator Research and Development (ARD) of the Matter and Technologies (MT) Program. Magnetic flux trapped in the Niobium bulk material of superconducting radio frequency (SRF) cavities degrades their quality factor and the accelerating gradient. The sensitivity of the cavity to trapped magnetic flux is mainly determined by the treatment, the geometry and the Niobium grain size and orientation. To potentially improve the flux expulsion characteristics of SRF cavities and hence the efficiency of future accelerator facilities, further studies of the trapping behavior are essential. For this purpose a so-called B-mapping system to monitor the magnetic flux along the outer cavity surface of 1.3 GHz TESLA-Type single-cell SRF cavities is currently under development at DESY. Contrary to former approaches, this system digitizes the sensor signals already inside of the cryostat to extensively reduce the number of required cable feedthroughs. Furthermore, the signal-to-noise ratio (SNR) and consequently the measuring sensitivity can be enhanced by shorter analog signal lines, less thermal noise and the Mu-metal shielding of the cryostat. In this contribution the design, the development process as well as first performance test results of the B-mapping system are presented. |
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DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2021-SUPTEV009 | ||
About • | Received ※ 01 July 2021 — Accepted ※ 31 March 2022 — Issue date ※ 09 April 2022 | ||
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WEPTEV003 | A Superconducting Magnetic Shield for SRF Modules with Strong Magnetic Field Sources | solenoid, SRF, gun, niobium | 637 |
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Frequently SRF modules require strong focusing magnets close to SRF cavities. The shielding of those magnetic fields to avoid flux trapping, for example during a quench, is a challenge. At HZB, the bERLinPro photo-injector module includes a 1.4 cell SRF cavity placed in close proximity to a superconducting (SC) focusing solenoid. At full solenoid operation, parts of the double mu-metal shield are expected to saturate. To prevent saturation, we developed a new superconducting Meissner-Shield. Several tests of different designs were performed both in the injector module and in the HoBiCaT test facility. The measured results of the final design show a significant shielding that are in good agreement with calculations. Based on these results, a reduction of the magnetic flux density in the mu-metal shields of almost one order of magnitude is expected The design has now been incorporated in the injector module. In this paper we will present the design, the setup and results of the final testing of the superconducting shield. | |||
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Poster WEPTEV003 [1.859 MB] | ||
DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPTEV003 | ||
About • | Received ※ 21 June 2021 — Revised ※ 16 August 2021 — Accepted ※ 21 August 2021 — Issue date ※ 15 March 2022 | ||
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||