Keyword: laser
Paper Title Other Keywords Page
MOPCAV002 Shape Evolution of C75 Large-Grain Niobium Half-Cells During Cavity Fabrication cavity, FEM, software, cryomodule 255
  • G. Ciovati
    JLab, Newport News, Virginia, USA
  Funding: U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
The largely anisotropic deformation of large-grain Nb discs during deep drawing into half-cells poses a challenge for achieving a desired shape accuracy. Two 5-cell cavities for the C75 CEBAF cryomodule rework program have been fabricated at Jefferson Lab from large-grain Nb discs directly sliced from an ingot. The shape of the inner surface of eight half-cells has been inspected using a FARO Edge laser scanner during the fabrication process and compared to the reference shape. On average, approximately 63% of the half-cell inner surface was found to be within 0.1 mm of the reference shape and ~90% to be within 0.2 mm, after the final equator machining. Several 5-cell C75 cavities have also been fabricated at Research Instruments, Germany, and measurements of the shape accuracy using a Zeiss 3D coordinate measuring machine gave similar results. One half-cell was measured both at Research Instruments and Jefferson Lab for comparison.
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPCAV002  
About • Received ※ 21 June 2021 — Accepted ※ 21 August 2021 — Issue date ※ 11 February 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
MOPFDV001 Investigation of an Alternative Path for SRF Cavity Fabrication and Surface Processing SRF, cavity, niobium, embedded 319
  • O. Hryhorenko, D. Longuevergne
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • C.Z. Antoine
    CEA-IRFU, Gif-sur-Yvette, France
  • F. Brisset
    ICMMO, Orsay, France
  • T. Dohmae
    KEK, Ibaraki, Japan
  The preparation of SRF cavities includes a lengthy, costly, and safety issued electrochemical polishing (EP or BCP) step to remove the damaged layer coming from the cavity fabrication. We have shown that most of the damage layer is originated from the rolling process during the preparation of the sheet material, while subsequent deep drawing tends to leave only µm thick damage layer. We propose a 2-steps mechanical process that allows us to easily get rid of the thick damage layer on the sheets before cavity forming. The process has been established on samples and extended to large disks ready for 1.3 GHz half-cell forming. The polished sheets will be then sent to KEK for half-cell forming and subsequent surface and material analysis before proceeding to half-cell welding. Former studies on the sample demonstrated that damages induced by forming can successfully be removed by recrystallization and less than 10 µm final chemistry.  
poster icon Poster MOPFDV001 [2.309 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-MOPFDV001  
About • Received ※ 25 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 15 May 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
TUPTEV010 Camera Placement in a Short Working Distance Optical Inspection System for RF Cavities cavity, focusing, controls, SRF 503
  • A. Macpherson, L.R. Buonocore, M. Di Castro, H. Gamper, A. Luthi
    CERN, Meyrin, Switzerland
  Inspection of the RF surface of cavities for the purpose of detecting surface anomalies has been well established, and is typically based on long working distance optical systems using on-axis camera and mirror systems to scan the cavity surface. In order to improve the systematic inspection of the full RF surface of large area cavities, a novel short working distance inspection system is being developed at CERN. This new system is based on a mechatronic robotic system to position that camera at normal incidence close to the cavity surface. To accommodate working distance fluctuations, and to provide increased depth of field resolution, the short working distance camera is coupled with a liquid lens focusing system, providing a programmable focusing function. Details of inspection bench design and first results are reported, as well as details on camera positioning optimisation and the proximity detection surveillance for collision-free scanning of the full-cavity surface.  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-TUPTEV010  
About • Received ※ 21 June 2021 — Revised ※ 25 August 2021 — Accepted ※ 18 November 2021 — Issue date ※ 30 January 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
WEPFDV007 Main Highlights of ARIES WP15 Collaboration SRF, site, cavity, experiment 571
  • O.B. Malyshev, P. Goudket, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • C.Z. Antoine
    CEA-IRFU, Gif-sur-Yvette, France
  • O. Azzolini, E. Chyhyrynets, G. Keppel, C. Pira, F. Stivanello
    INFN/LNL, Legnaro (PD), Italy
  • G. Burt, D.J. Seal, D.A. Turner
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • G. Burt, B.S. Sian
    Lancaster University, Lancaster, United Kingdom
  • O. Kugeler, D.B. Tikhonov
    HZB, Berlin, Germany
  • S.B. Leith, A.O. Sezgin, M. Vogel
    University Siegen, Siegen, Germany
  • A. Medvids, P. Onufrijevs
    Riga Technical University, Riga, Latvia
  • R. Ries, E. Seiler
    Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
  • B.S. Sian
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A. Sublet, G. Vandoni, L. Vega Cid, W. Venturini Delsolaro, P. Vidal García
    CERN, Meyrin, Switzerland
  • D.A. Turner
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  Funding: European Commission’s ARIES collaboration H2020 Research and Innovation Programme under Grant Agreement no. 730871
An international collaboration of research teams from CEA (France), CERN (Switzerland), INFN/LNL (Italy), HZB and USI (Germany), IEE (Slovakia), RTU (Latvia) and STFC/DL (UK), are working together on better understanding of how to improve the properties of superconducting thin films (ScTF) for RF cavities. The collaboration has been formed as WP15 in the H2020 ARIES project funded by EC. The systematic study of ScTF covers: Cu substrate polishing with different techniques (EP, SUBU, EP+SUBU, tumbling, laser), Nb, NbN, Nb3Sn and SIS film deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application of all obtained knowledge on polishing, deposition and characterisation, Laser post deposition treatments, DC magnetisation characterisation, application to the QPR samples for testing the films at RF conditions. The preparation, deposition and characterisation of each sample involves 3-5 partners enhancing the capability of each other and resulting in a more complete analysis of each film. The talk will give an overview of the collaborative research and will be an introduction to the detailed talks given by the team members.
poster icon Poster WEPFDV007 [2.013 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-SRF2021-WEPFDV007  
About • Received ※ 19 June 2021 — Accepted ※ 12 February 2022 — Issue date ※ 10 April 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)