正在建设中的上海光源梦之线(Dreamline)是一条宽能段、超高能量分辨率的软X射线光束线。如此高指标的光束线在建设过程中有许多难点需要克服,其中光学元件的热变形是达到数万分辨能力的主要障碍。梦之线采用的5 m长的波荡器会产生很高的热辐射从而使各光学元件,特别是第一块平面镜(M1)和第二块平面镜(M2)发生热形变进而影响整个光束线的性能。因此本文计算了Dreamline各光学元件的热功率密度分布,在此基础上对各光学元件进行了稳态热分析,得到M1、M2达到热平衡时的温度,热变形和面形误差分布,进而利用热变形结果对光束线进行了追迹,并且设计了一套热修正装置指导单色仪自身的聚集调节从而消除镜面热变形对光束线性能的影响。结果表明,即使在镜面热变形最高的情况下,通过对各光学元件进行有效的冷却并通过单色仪自身的聚集调节能消除镜面热形变对光束线性能的影响。 Under construction Shanghai Light Dreamline is a wide energy segment, ultra-high-energy soft X-ray beamline. Such a high index of beam line in the construction process has many difficulties to overcome, including thermal distortion of optical components is to reach tens of thousands of resolution of the main obstacles. The 5 m-long undulator used in the Dreamline generates high heat radiation that thermally distorts the optical elements, especially the first mirror (M1) and the second mirror (M2), affecting the entire beamline performance. Therefore, this paper calculates the thermal power density distribution of each optical element of Dreamline. Based on this, the steady state thermal analysis of each optical element is carried out to obtain the temperature, thermal deformation and profile error distribution when M1 and M2 reach the thermal equilibrium, The results of deformation traced the beamline, and a set of thermal correction device was designed to guide the monochromator to adjust its own aggregation, so as to eliminate the influence of mirror thermal deformation on the beamline performance. The results show that the effect of specular thermal deformation on the beamline performance can be eliminated by effectively cooling the optics and by adjusting the monochromator’s own focus even with the highest specular thermal deformation.