Title |
Study on Nitrogen Infusion for 1.3 GHz SRF Cavities Using J-PARC Furnace |
Authors |
- K. Umemori, T. Dohmae, M. Egi, Y. Hori, E. Kako, T. Konomi, S. Michizono, T. Saeki, H. Sakai, Y. Yamamoto
KEK, Ibaraki, Japan
- J. Kamiya
JAEA/J-PARC, Tokai-mura, Japan
- S. Kurosawa, K. Takeishi
JAEA, Ibaraki-ken, Japan
- T. Okada
Sokendai, Ibaraki, Japan
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Abstract |
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.
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Paper |
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Conference |
LINAC2018 |
Series |
Linear Accelerator Conference (29th) |
Location |
Beijing, China |
Date |
16-21 September 2018 |
Publisher |
JACoW Publishing, Geneva, Switzerland |
Editorial Board |
Guoxi Pei (IHEP, Beijing, China); Volker RW Schaa (GSI, Darmstadt, Germany); Yong Ho Chin (KEK, Tsukuba, Japan); Shinian Fu (IHEP, Beijing, China); Ning Zhao (IHEP, Beijing, China) |
Online ISBN |
978-3-95450-194-6 |
Online ISSN |
2226-0366 |
Received |
20 September 2018 |
Accepted |
20 September 2018 |
Issue Date |
18 January 2019 |
DOI |
doi:10.18429/JACoW-LINAC2018-TUPO071 |
Copyright |
Published by JACoW Publishing under the terms of the Creative Commons Attribution 3.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI. |
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