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 - Okada, T. AU - Akai, K. AU - Furuya, T. AU - Mitsunobu, S. AU - Morita, Y. AU - Nishiwaki, M. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Loading Test of Hom Dampers for Superconducting Cavities for High Current at 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 is an e⁻e⁺ collider, which is an upgraded accelerator of KEKB with the aim to increase the luminosity by more than one order. The superconducting cavities are used in the electron ring. The superconducting cavities were designed as a HOM-damped structure for KEKB and were operated up to 1.4 A in KEKB. However, the design storage current of the electron ring for SuperKEKB is 2.6 A, which is about twice the achievement current of KEKB. The HOM power is estimated to increase from 16 kW, which is the performance value in KEKB, to over 35 kW. This large load is unacceptable for the ferrite HOM dampers mounted on both sides of the cavity. As a countermeasure, duct type SiC HOM dampers are inserted between the cavities. The HOM damper load tests were performed during normal beam operation with a maximum current of 1.1 A. The load on the downstream ferrite HOM damper decreased due to the HOM power absorbed by the upstream SiC damper. In addition, the load was found to be dependent on the beam filling pattern. We will present the results and discussion of beam tests on the loading of HOM dampers and the dependence on the beam filling pattern in SuperKEKB. PB - JACoW Publishing CP - Geneva, Switzerland SP - 271 EP - 274 KW - HOM KW - cavity KW - SRF KW - superconducting-cavity KW - operation DA - 2023/09 PY - 2023 SN - 2673-5504 SN - 978-3-95450-234-9 DO - doi:10.18429/JACoW-SRF2023-MOPMB068 UR - https://jacow.org/srf2023/papers/mopmb068.pdf ER -