JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Ozeki, K. AU - Kamigaito, O. AU - Sakamoto, N. AU - Suda, K. AU - Yamada, K. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - FPC for RIKEN QWR J2 - Proc. of SRF2021, East Lansing, MI, USA, 28 June-02 July 2021 CY - East Lansing, MI, USA T2 - International Conference on RF Superconductivity T3 - 20 LA - english AB - In RIKEN, three cryomodules which contain ten SC-QWRs in total (4 + 4 + 2) were constructed, and beam supply has been started since last year. The FPCs for RIKEN QWR have a disk-type single vacuum window at room-temperature region. A vacuum leakage occurred at one FPC, after 4th cool-down test. In addition, second vacuum leakage occurred at another FPC, after starting beam supply. A dew condensation at air side of vacuum window may degrade the brazing of vacuum window. In order to prevent a dew condensation and to restore damaged FPCs, an additional outer vacuum window using machinable ceramics was designed and attached to the FPCs. In this contribution, a structure of the FPC, troubles, provision for those troubles, and plan for reconstruction are reported. PB - JACoW Publishing CP - Geneva, Switzerland SP - 825 EP - 828 KW - vacuum KW - SRF KW - Windows KW - linac KW - cryomodule DA - 2022/10 PY - 2022 SN - 2673-5504 SN - 978-3-95450-233-2 DO - doi:10.18429/JACoW-SRF2021-THPTEV001 UR - https://jacow.org/srf2021/papers/thptev001.pdf ER -