Chen, S. Deng, H.X. Feng, C. Liu, B. Liu, T. Qi, Z. Zhang, K.Q. Zhao, Z.T. JACoW Publishing Geneva, Switzerland 2673-7035 978-3-95450-224-0 10.18429/JACoW-FLS2023-TU4P08 English 91-94 FEL emittance linac MMI undulator Contribution to a conference proceedings 2024 2024-01 https://doi.org/10.18429/JACoW-FLS2023-TU4P08 http://jacow.org/fls2023/papers/tu4p08.pdf As an important measure of improving the efficiency and usability of X-ray free electron laser facilities, parallel operation of multiple undulator lines realized by a beam switchyard has become a standard configuration in the recent built XFEL facilities. SXFEL-UF, the first soft X-ray free electron laser user facility in China, has finished construction and commissioning recently. The electron beams from the linac are separated and delivered alternately to the two parallel undulator beam lines through a beam switchyard. A stable and fast kicker magnet is used to achieve bunch-by-bunch separation. Optics measures are applied to mitigate the impact of various collective effects, such as coherent synchrotron radiation and micro-bunching instability, on the beam quality after passing through the deflection line of the beam switchyard. In this study, the comprehensive physical design of the beam switchyard is described and the latest results of its commissioning process are presented.