Guo, J. Daly, E.F. Drachuk, E. Fernandes, R.R. Henry, J. Holmes, D. Matalevich, J. Park, G.-T. Rimmer, R.A. Savransky, D. Smith, K.S. Xu, W. Zaltsman, A. JACoW Publishing Geneva, Switzerland 2673-5504 978-3-95450-234-9 10.18429/JACoW-SRF2023-MOPMB078 English 293-297 cavity simulation HOM operation electron Contribution to a conference proceedings 2023 2023-09 https://doi.org/10.18429/JACoW-SRF2023-MOPMB078 https://jacow.org/srf2023/papers/mopmb078.pdf Among the EIC¿s numerous RF subsystems, the electron storage ring¿s (ESR) 591 MHz fundamental RF system is one of the most challenging. Each cavity in the system will handle up to 2.5 A of beam current and supply up to 600 kW beam power under a wide range of voltage. The EIC R&D plan includes the design, fabrication and testing of such a cavity. In this paper, we will report the latest status and findings of the ongoing design and prototyping of this cavity, including the RF and mechanical/thermal design, fabrication design, and the progress of fabrication.