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 - Akai, K. AU - Furuya, T. AU - Mitsunobu, S. AU - Morita, Y. AU - Okada, T. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Operating Experience of SRF System at High Beam Current in SuperKEKB J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023 CY - Grand Rapids, MI, USA T2 - International Conference on RF Superconductivity T3 - 21 LA - english AB - SuperKEKB aims for high luminosity on the order of 10³⁵ cm⁻²s⁻¹ with beam currents of 2.6 A for electron and 3.6 A for positron to search new physics beyond the Standard Model in the B meson regime. In recent operations, we achieved a new record of luminosity of 4.65×10³⁴ cm⁻²s⁻¹ with 1.1 A for electron and 1.3 A for positron. The SRF system that was designed for KEKB, the predecessor of SuperKEKB, is operating stably with the high beam currents owing to the measures against the large beam powers and the large higher-order-mode (HOM) powers. As a measure against the large beam powers, our SRF cavities have increased a coupling of high-power input couplers during the KEKB operation. As a measure against the large HOM power, newly developed SiC HOM dampers have been installed in the SuperKEKB ring. In addition, we have established the horizontal high-pressure rinse method to recover the cavity performance that has degraded due to vacuum works and accidents in the long-term operation. In this report, we will present our operation experience of SRF system under the high beam currents. PB - JACoW Publishing CP - Geneva, Switzerland SP - 38 EP - 42 KW - cavity KW - operation KW - HOM KW - SRF KW - luminosity DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOIXA05 UR - https://jacow.org/srf2023/papers/moixa05.pdf ER -