Author: Hori, Y.
Paper Title Page
THPB021 Trial of Nitrogen Infusion and Nitrogen Doping by Using J-PARC Furnace 775
 
  • T. Konomi, T. Dohmae, Y. Hori, E. Kako, T. Kubo, G.-T. Park, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
  • J. Kamiya, K. Takeishi
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Nagata
    ULVAC, Inc., Tsukuba, Japan
 
  KEK has been carrying out SRF cavity developments toward higher Q-values and higher accelerating gradients. In the past nitrogen-doping was tested using the KEK furnaces, but it did not succeed. This time nitrogen infusion and nitrogen doping are tested using the J-PARC's furnace, which has an oil-free pumping system and is mainly pumped by a 10000 L/s cryopump and three 3000 L/s turbo pumps. Nitrogen pressure is controlled by a variable leak valve and an additional turbo pump. To avoid performance degradation during heat treatment, flanges of cavities are covered by Nb caps and foils. Nitrogen infusion at 120 degrees was applied to a single cell cavity and cavity performance was measured by vertical tests after HPR and assembly. Nitrogen doping at 800 degrees is also applied to another single cell cavity. After applying EP and HPR, vertical tests were carried out. Nb samples were also installed into the furnace during heat treatment. Surfaces are analyzed by SIMS and XPS. In this presentation, we report procedure of nitrogen infusion and doping, vertical test results and results of surface analysis.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB021  
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