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TY - CONF AU - Umemori, K. AU - Dohmae, T. AU - Egi, M. AU - Hori, Y. AU - Kako, E. AU - Kamiya, J. AU - Konomi, T. AU - Kurosawa, S. AU - Michizono, S. AU - Okada, T. AU - Saeki, T. AU - Sakai, H. AU - Takeishi, K. AU - Yamamoto, Y. ED - Schaa, Volker RW ED - Pei, Guoxi ED - Chin, Yong Ho ED - Fu, Shinian ED - Zhao, Ning TI - Study on Nitrogen Infusion for 1.3 GHz SRF Cavities Using J-PARC Furnace J2 - Proc. of LINAC2018, Beijing, China, 16-21 September 2018 CY - Beijing, China T2 - Linear Accelerator Conference T3 - 29 LA - english AB - Nitrogen infusion (N-infusion) is new surface treatment technique for niobium SRF (Superconducting RF) cavities. After cooling down from 800 degree C heat treatment, a vacuum furnace and cavities are kept 120 degree C, 48 hours with about 3 Pa Nitrogen. Improvement of Q-value and accelerating gradient is expected. We used J-PARC furnace, since N-infusion procedure requires clean vacuum furnace. It has a cryo-pump and turbo molecular pumps and its vacuum system is oil-free system. Six times of N-infusion tests were carried out, while changing vacuum condition, N-infusion temperature, Nitrogen pressure, niobium material and so on. Niobium caps were mounted on cavities to avoid contaminations on inner surfaces. Some of trials were successful and vertical test results showed improvement of Q-values and accelerating gradient. However, some of them were not. Most of bad cases showed degradation of Q-values above 5 MV/m. Details of heat treatment procedure including N-infusion and vertical test results are shown in this presentation. PB - JACoW Publishing CP - Geneva, Switzerland SP - 499 EP - 502 KW - cavity KW - SRF KW - injection KW - background KW - vacuum DA - 2019/01 PY - 2019 SN - 2226-0366 SN - 978-3-95450-194-6 DO - DOI: 10.18429/JACoW-LINAC2018-TUPO071 UR - http://jacow.org/linac2018/papers/tupo071.pdf ER -