Meng, F. Huang, T.M. Lin, H.Y. Ma, Q. Pan, W.M. Zhai, J.Y. Zhang, P. Zheng, H.J. JACoW Geneva, Switzerland 978-3-95450-191-5 10.18429/JACoW-SRF2017-MOPB071 English 223-226 MOPB071 ion HOM cavity simulation site Contribution to a conference proceedings 2018 2018-01 https://doi.org/10.18429/JACoW-SRF2017-MOPB071 http://jacow.org/srf2017/papers/mopb071.pdf For high current accelerator, the efficient higher-order mode (HOM) damping is always an important issue. HOM damper with microwave absorbing material is a key component for high power and broadband HOM damping application. To pursue the high damping efficiency, some ideal material with good microwave absorbing capacity is essential during the RF design and fabrication phase. Sometimes the selection and test of material is the first step and also a long step. This paper will present the recent work on HOM dampers for BEPCII 500MHz cavity and CEPC 650MHz cavity in IHEP.