Bing, B. Gu, K.X. Huang, T.M. Ma, Q. Meng, F. Pan, W.M. JACoW Geneva, Switzerland 978-3-95450-191-5 10.18429/JACoW-SRF2017-MOPB054 English 183-185 MOPB054 ion electron cavity simulation multipactoring Contribution to a conference proceedings 2018 2018-01 https://doi.org/10.18429/JACoW-SRF2017-MOPB054 http://jacow.org/srf2017/papers/mopb054.pdf A single-window coaxial coupler at warm has been designed for high intensity heavy-ion accelerator. The coupler is designed to handle 100 kW CW power of 325 MHz and is currently being fabricated. T-bend transition and doorknob have been taken into account. The length of the T-bend short circuit is sensitive to S parameters and contributes to the online adjustment of VSWR in RF conditioning. The doorknob type is adopted to realize the transition from a half-height WR 2300 waveguide to a coaxial line ended with a coupling antenna. This paper describes the RF design, thermal stress and heat load analysis of the coupler as well as multipacting simula-tions.