Xu, Z.M. Yang, C. Zhang, W.Q. Zhong, Y.P. JACoW Publishing Geneva, Switzerland 2673-5520 978-3-95450-250-9 10.18429/JACoW-MEDSI2023-THPPP012 English 293-295 FEL laser synchrotron free-electron-laser electron Contribution to a conference proceedings 2024 2024-07 https://doi.org/10.18429/JACoW-MEDSI2023-THPPP012 https://jacow.org/medsi2023/papers/thppp012.pdf For the monochromator pre-mirror in FEL-1 at S3FEL, the deformation induced by high heat load result in severe effects on the beam quality during its off-axis rotation. To meet the pre-mirror shape error requirement for X-ray coherent transport, an integra-tion of passive cooling and active heating systems for thermal management of the monochromator pre-mirror has been proposed, developed, and modelled. An ac-tive heating system with multiple electric heaters is adopted to compensate for the pre-mirror shape fur-ther. Finally, using MHCKF model, the optimization of multiple heat fluxes generated by all electric heaters was accomplished. The results show that the thermal management using passive cooling and active heat schemes is effective to obtain high-precision surface shape for the pre-mirror.