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 - Nishiwaki, M. AU - Abe, T. AU - Akai, K. AU - Enomoto, S. AU - Furuya, T. AU - Kabe, A. AU - Kageyama, T. AU - Kobayashi, T. AU - Marutsuka, K. AU - Mitsunobu, S. AU - Morita, Y. AU - Nakanishi, K. AU - Ogasawara, S. AU - Okada, T. AU - Ono, M. AU - Sakai, H. AU - Takeuchi, Y. AU - Watanabe, K. AU - Yoshida, Ma. AU - Yoshimoto, S.I. AU - Yoshino, K. ED - Biagini, Maria Enrica ED - Chrin, Jan ED - Giabbai, Manuela ED - Iungo, Massimiliano ED - Schaa, Volker R.W. TI - SuperKEKB Operating Experience of RF System at High Current J2 - Proc. of eeFACT2022, Frascati, Italy, 12-16 September 2022 CY - Frascati, Italy T2 - ICFA Advanced Beam Dynamics Workshop on High Luminosity Circular e+e- Colliders T3 - 65 LA - english AB - SuperKEKB aims for high luminosity on the order of 10³⁵ cm⁻²s⁻¹ with high beam currents of 2.6 A for electron and 3.6 A for positron to search a new physics beyond the Standard Model in the B meson regime. In recent operations, we achieved new record of the luminosity of 4.7x10³⁴ cm⁻²s⁻¹ with 1.1 A for electron and 1.3 A for positron. The RF system that is basically reused from KEKB is operating stably in the high current operation owing to the measures against to large beam power and HOM power. To cope with the large beam power, it has been increased the number of klystrons that drive only one normal conducting cavity (ARES) and reinforced the input couplers of ARES. As a measure against HOM power, the additional HOM dampers have been installed to superconducting cavities. One-third of LLRF control systems have been replaced with newly developed digital system to improve accuracy and flexibility. New damper system for coupled bunch instability expected in high current has been installed to new digital system. In this report, operation status of RF system under the high current operation will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 131 EP - 140 KW - cavity KW - operation KW - HOM KW - klystron KW - LLRF DA - 2022/02 PY - 2022 SN - 2673-7027 SN - 978-3-95450-236-3 DO - doi:10.18429/JACoW-eeFACT2022-WEXAS0102 UR - https://jacow.org/eefact2022/papers/wexas0102.pdf ER -