Gu, D. Wang, Z. Zhang, M. JACoW Publishing Geneva, Switzerland 2673-7035 978-3-95450-224-0 10.18429/JACoW-FLS2023-WE4P13 English 174-176 linac electron FEL emittance cryomodule Contribution to a conference proceedings 2024 2024-01 https://doi.org/10.18429/JACoW-FLS2023-WE4P13 http://jacow.org/fls2023/papers/we4p13.pdf Shanghai HIgh Repetition Rate X-ray Free Electron Laser and Extreme Light Facility (SHINE) is a hard X-ray FEL facility which is driven by a 1.3 km supercon-ducting Linac, aims to provide high repetition rate pulses up to 1 MHz. In this study, we present the physics design of the SHINE accelerator and considerations of beam dynamics optimizations. Start-to-end simulation results show that, a high brightness electron beam with over 1500 A quasi-flat-top current can be attained which fully meet the requirements of FEL lines. Furthermore, design of the bypass line is also discussed.