Author: Dhakal, P.
Paper Title Page
WEPRI069 Reproducibility of High-Q SRF Cavities by High Temperature Heat Treatment 2651
 
  • P. Dhakal, G. Ciovati, P. Kneisel, G.R. Myneni
    JLab, Newport News, Virginia, USA
 
  Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
Recent work on high-temperature (> 600 °C) heat treatment of ingot Nb cavities in a customized vacuum furnace for several hours showed the possibility of achieving Q0-values of up to ~5×1010 at 2.0 K, 1.5 GHz and accelerating gradients of ~20 MV/m. This contribution presents results on further studies of the heat treatment process to produce cavities with high Q0 values for continuous-wave accelerator application. Single-cell cavities of different Nb purity have been processed through few cycles of heat-treatments and chemical etching. Measurements of Q0 as a function of temperature at low RF field and of Q0 as a function of the RF field at or below 2.0 K have been made after each treatment. Measurements by TOF-SIMS of the impurities’ depth profiles were made on samples heat treated with the cavities.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI069  
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WEPRI070 Mechanical Properties of Ingot Nb Cavities 2654
 
  • G. Ciovati, P. Dhakal, P. Kneisel, J.D. Mammosser, J. Matalevich, G.R. Myneni
    JLab, Newport News, Virginia, USA
 
  Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
This contribution presents the results of measurements of the resonant frequency and of strain along the contour of a single-cell cavity made of ingot Nb subjected to increasing uniform differential pressure, up to 6 atm. The data were used to infer mechanical properties of this material after cavity fabrication, by comparison with the results from simulation calculations done with ANSYS. The objective is to provide useful information about the mechanical properties of ingot Nb cavities which can be used in the design phase of SRF cavities intended to be built with this material.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI070  
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