Author: May, A.J.
Paper Title Page
THP027 Cryogenics Performance of the Vertical Cryostat for Qualifying ESS-SRF High Beta Cavities 895
 
  • S.M. Pattalwar, R.K. Buckley, P.C. Hornickel, K.J. Middleman, M.D. Pendleton, P. Pizzol, P.A. Smith, T.M. Weston, A.E. Wheelhouse, S. Wilde
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.J. May, A. Oates, J.T.G. Wilson
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  An innovative vertical cryostat has been developed and commissioned at STFC Daresbury Laboratory for qualifying the high-beta SRF cavities for the ESS (European Spallation Source). The cryostat is designed to test 3 dressed cavities in horizontal configuration in one cold run at 2K. The cavities are cooled to 2K with superfluid liquid helium filled into individual helium jackets of the cavities. This reduces the liquid helium consumption by more than 70% in comparison with the conventional vertical tests. The paper describes the cryogenic system and its performance with detail discussions on the initial results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP027  
About • paper received ※ 22 June 2019       paper accepted ※ 03 July 2019       issue date ※ 14 August 2019  
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THP048 Characterization of Flat Multilayer Thin Film Superconductors 968
SUSP037   use link to see paper's listing under its alternate paper code  
 
  • D. Turner, A.J. May
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • G. Burt, L. Gurran
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • K.D. Dumbell, N. Pattalwar, S.M. Pattalwar
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • T. Junginger, O.B. Malyshev
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The maximum accelerating gradient of SRF cavities can be increased by raising the field of initial flux penetration, Hvp. Thin alternating layers of superconductors and insulators (SIS) can potentially increase Hvp. Magnetometry is commercially available but consists of limitations, such as SQUID measurements apply a field over both superconducting layers, so Hvp through the sample cannot be measured. If SIS structures are to be investigated a magnetic field must be applied locally, from one plane of the sample, with no magnetic field on the opposing side to allow Hvp to be measured. A magnetic field penetration experiment has been developed at Daresbury laboratory, where a VTI has been created for a cryostat where Hvp of a sample can be measured. The VTI has been designed to allow flat samples to be measured to reduce limitations such as edge effects by creating a DC magnetic field smaller than the sample. A small, parallel magnetic field is produced on the sample by the use of a ferrite yoke. The field is increased to determine Hvp by using 2 hall probes either side of the sample.  
poster icon Poster THP048 [0.327 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP048  
About • paper received ※ 23 June 2019       paper accepted ※ 30 June 2019       issue date ※ 14 August 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)