Author: Pira, C.
Paper Title Page
MOP007 400 MHz Seamless Copper Cavity in the Framework of FCC Study 36
 
  • O. Azzolini, G. Keppel, C. Pira
    INFN/LNL, Legnaro (PD), Italy
 
  In the framework of the FCC study the production of 400 MHz copper cavities is one of the key challenges for the development of more efficient superconducting RF cavities. Any progress on substrate manufacturing and preparation will have an immediate impact on the final RF performance, as it was demonstrated by the seamless cavities produced for the HIE-ISOLDE project. Spinning is a potential alternative to conventional production methods of copper single and multi-cells. In this work is presented the first 400 MHz copper SRF cavity prototype produced via Spinning at Laboratori Nazionali di Legnaro of INFN. The production process is explained starting from a copper foil of 1000 mm diameter and 4mm thick to arrive to a seamless 400 MHz cavity. Moreover, the metrology of the cavity and the analysis of the influence of intermediate thermal treatments among each steps of cold work are shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP007  
About • paper received ※ 23 June 2019       paper accepted ※ 02 July 2019       issue date ※ 14 August 2019  
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TUP026 Vibro-tumbling as an Alternative to Standard Mechanical Polishing Techniques for SRF Cavities 464
 
  • E. Chyhyrynets, O. Azzolini, V.A. Garcia, G. Keppel, C. Pira, F. Stivanello, L. Zanotto
    INFN/LNL, Legnaro (PD), Italy
 
  Funding: Work supported by the INFN V group experiment TEFEN, Agreement N. KE2722/BE/FCC and from the European Union’s H2020 Framework Programme under grant agreement no. 764879 (EASITrain)
Centrifugal Barrel Polishing (CBP) is a common tool in the Nb bulk SC cavities production, prior to elec-tropolishing (EP). Indeed, the mechanical polishing is fun-damental also in the superconducting thin film resonant cavities in which one of the main issues that limits the per-formances is the surface preparation. A promising vi-bro-tumbling technique is being studied and implemented with a possibility to replace or improve mechanical treat-ment steps (grinding, barrel polishing). The simplic-ity of the technology allows it to adapt to any cavity geom-etry, both for Nb and Cu materials. The presented work contains last results on 6 GHz cavities obtained at LNL-INFN, both Nb bulk and Cu cavities.
 
poster icon Poster TUP026 [5.584 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP026  
About • paper received ※ 21 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
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THP041 Impact of the Cu Substrate Surface Preparation on the Morphological, Superconductive and RF Properties of the Nb Superconductive Coatings 935
 
  • C. Pira, E. Chyhyrynets
    INFN/LNL, Legnaro (PD), Italy
  • C.Z. Antoine
    CEA-IRFU, Gif-sur-Yvette, France
  • X. Jiang, S.B. Leith, M. Vogel
    University Siegen, Siegen, Germany
  • A. Katasevs, J. Kaupužs, A. Medvids, P. Onufrijevs
    Riga Technical University, Riga, Latvia
  • O. Kugeler
    HZB, Berlin, Germany
  • O.B. Malyshev, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Ries, E. Seiler
    Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
  • A. Sublet
    CERN, Meyrin, Switzerland
 
  Funding: This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No 730871.
Nowadays, one of the main issues of the superconducting thin film resonant cavities is the Cu surface preparation. A better understanding of the impact of copper surface preparation on the morphological, superconductive (SC) and RF properties of the coating, is mandatory in order to improve the performances of superconducting cavities by coating techniques. ARIES H2020 collaboration includes a specific work package (WP15) to study the influence of Cu surface polishing on the SRF performances of Nb coatings that involves a team of 8 research groups from 7 different countries. In the present work, a comparison of 4 different polishing processes for Cu (Tumbling, EP, SUBU, EP+SUBU) is presented through the evaluation of the SC and morphological properties of Nb thin film coated on Cu planar samples and QPR samples, polished with different procedures. Effects of laser annealing on Nb thin films have also been studied. Different surface characterizations have been applied: roughness measurements, SEM, EDS, XRD, AFM, and thermal and photo-stimulated exoelectrons measurements. SC properties were evaluated with PPMS, and QPR measurements will be carry out at HZB in the beginning of 2019.
 
poster icon Poster THP041 [3.196 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP041  
About • paper received ※ 23 June 2019       paper accepted ※ 05 July 2019       issue date ※ 14 August 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)