Author: Malyshev, O.B.
Paper Title Page
THPOGE09 Split Thin Film SRF 6 GHz Cavities 814
 
  • B.S. Sian, G. Burt, D.J. Seal
    Lancaster University, Lancaster, United Kingdom
  • G. Burt, O.B. Malyshev, D.J. Seal, R. Valizadeh
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • O.B. Malyshev, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • H.S. Marks
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  
  Many current accelerators use cavities that are manufactured as two half cells that are electron beam welded together, the weld is across the peak surface current of the cavity. This weld can lead to large increases in surface resistance and limit the performance of thin film coated cavities. Many problems with the coating process for thin film Superconducting Radio Frequency (SRF) cavities are also due to this weld. Thin film SRF cavities can perform as well as bulk niobium cavities if the cavity is manufactured seamlessly, without any weld, as they have a more uniform surface, however, they are much more difficult and expensive to manufacture. A cavity with a split longitudinally, parallel to the direction of the electric field, would not need to be welded. These seamless cavities are easier to manufacture and coat. This opens the possibilities to coat with new materials and multilayer coatings. These cavities may allow SRF cavities to operate at significantly better parameters (higher quality factor and maximum accelerating field) than current state of the art cavities. This work discusses development and testing of longitudinally split seamless cavities at Daresbury Laboratory.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOGE09  
About • Received ※ 25 August 2022 — Revised ※ 28 August 2022 — Accepted ※ 12 September 2022 — Issue date ※ 15 October 2022
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THPOGE10 RF Characterisation of Bulk Niobium and Thin Film Coated Planar Samples at 7.8 GHz 818
SUPCPA04   use link to see paper's listing under its alternate paper code  
 
  • D.J. Seal, G. Burt, O.B. Malyshev, B.S. Sian, R. Valizadeh
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • G. Burt, D.J. Seal, B.S. Sian
    Lancaster University, Lancaster, United Kingdom
  • E. Chyhyrynets, C. Pira
    INFN/LNL, Legnaro (PD), Italy
  • O. Hryhorenko, D. Longuevergne
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • O.B. Malyshev, E.A. Marshall, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • H.S. Marks
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  
  Research is ongoing into the use of superconducting thin films to replace bulk niobium for future radio frequency (RF) cavities. A key part of this research requires measuring the RF properties of candidate films. However, coating and testing thin films on full-sized cavities is both costly and time-consuming. Instead, films are typically deposited on small, flat samples and characterised using a test cavity. A cost-effective facility for testing such samples has recently been built and commissioned at Daresbury Laboratory. The facility allows for low power surface resistance measurements at a resonant frequency of 7.8 GHz, temperatures down to 4 K and sample surface magnetic fields up to 1 mT. A brief overview of this facility as well as recent results from measurements of both bulk Nb and thin film coated samples will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOGE10  
About • Received ※ 11 August 2022 — Revised ※ 19 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 16 September 2022
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THPOGE02 Investigation of HiPIMS-Coated S(I)S Structures for SRF Cavities 805
SUPCPA02   use link to see paper's listing under its alternate paper code  
 
  • A.Ö. Sezgin, X. Jiang, M. Vogel
    University Siegen, Siegen, Germany
  • C.Z. Antoine
    CEA-IRFU, Gif-sur-Yvette, France
  • S. Keckert, J. Knobloch, O. Kugeler, D.B. Tikhonov
    HZB, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
  • O.B. Malyshev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Ries, E. Seiler
    Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
  • L.G.P. Smith
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  
  The sustainable next generation particle accelerators require innovative solutions to overcome the current technological challenges set by existing bulk niobium superconducting radio-frequency (SRF) cavities. Thin film-based multilayer structures in the form of superconductor-insulator-superconductor (SIS) may be the long-sought-after breakthrough for higher performance SRF cavities by enhancing both accelerating gradients and quality factors. In order to understand better the underlying mechanisms of SIS structures to be coated onto (S)RF cavities, we study various material properties with the resultant superconducting properties of high-power im-pulse magnetron sputtering (HiPIMS)-coated S(I)S structures of Nb-(AlN)-NbN with different thicknesses which are designed to be coated mainly on OFHC copper (Cu) samples for more efficient SRF cavities. This contribution presents materials properties of the aforementioned HiPIMS-coated S(I)S structures as well as the superconducting and RF behaviours of these multilayers which are assessed comparatively via DC and AC magnetization techniques.  
poster icon Poster THPOGE02 [0.747 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2022-THPOGE02  
About • Received ※ 25 August 2022 — Revised ※ 30 August 2022 — Accepted ※ 01 September 2022 — Issue date ※ 02 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)