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TY - CPAPER AU - Zheng, H.J. AU - Chen, J.F. AU - Gao, J. AU - Pagani, C. TI - HOM Calculations for Different Cavities and Beam Induced HOM Power Analysis of ESS J2 - Proc. of International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 AB - For different design of ESS superconducting cavities, the higher order modes (HOM's) of monopoles, dipoles, quadrupoles and sextupoles are found. Their R/Q values are also calculated. Main HOM related issues are the beam instabilities and the HOM induced power especially from TM monopoles. The analysis for the beam induced HOM voltage and power in this paper showed that, if the HOM frequency is a few kHz away from the beam spectrum, it is not a problem. In order to understand the effects of the beam structure, analytic expressions are developed. With these expressions, the induced HOM voltage and power were calculated by assuming external Q for each HOM. Our analysis confirm that, with thebeam structure of ESS and a good cavity design, no special tight tolerances are required for cavity fabrication and no HOM couplers in the cavity beam pipes are planned. PB - JACoW CY - Geneva, Switzerland SP - 1061 EP - 1065 KW - HOM KW - cavity KW - sextupole KW - dipole KW - quadrupole DA - 2015/12 PY - 2015 SN - 978-3-95450-178-6 DO - 10.18429/JACoW-SRF2015-THPB004 UR - http://srf2015.vrws.de/papers/thpb004.pdf ER -