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 - Sha, P. AU - Dong, C. AU - He, F.S. AU - Jin, S. AU - Li, Z.Q. AU - Liu, B.Q. AU - Mi, Z.H. AU - Pan, W.M. AU - Zhai, J.Y. AU - Zhang, X.Y. AU - Zheng, H.J. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - Research and Development of 650 MHz Cavities for CEPC 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 - 650 MHz 2-cell superconducting cavities are proposed for the main ring of the Circular Electron Positron Collider (CEPC). The design, fabrication, surface treatment (buffered chemical polishing) and vertical tests of the cavities with HOM couplers were conducted. The performance of the cavity at 2 K is not affected by the HOM coupler. The maximum intrinsic quality factor of the cavity with the HOM coupler reached 3.1·10¹⁰ at 20 MV/m. The vertical test results showed that the fundamental mode external quality factor of all HOM couplers is an order of magnitude larger than quality factor of the cavity. The HOM damping results for the 650 MHz 2-cell cavity were also measured at cryogenic temperature and compared with the simulated and measured results at room temperature. Two 650 MHz 2-cell cavities jacketed have been integrated into a test cryomodule for CEPC. Another 650 MHz 2-cell cavity reached 6·10¹⁰ at 22 MV/m after nitrogen infusion. In addition, two 650 MHz 1-cell cavities reached 2.7·10¹⁰ at 35 MV/m (fine grain) and 3.6·10¹⁰ at 32 MV/m (large grain) after electro-polishing, respectively. In future, electro-polishing will be applied to 650 MHz 2-cell cavity soon. PB - JACoW Publishing CP - Geneva, Switzerland SP - 616 EP - 618 KW - cavity KW - HOM KW - cryomodule KW - SRF KW - superconducting-cavity DA - 2022/10 PY - 2022 SN - 2673-5504 SN - 978-3-95450-233-2 DO - doi:10.18429/JACoW-SRF2021-WEPCAV012 UR - https://jacow.org/srf2021/papers/wepcav012.pdf ER -