In order to evaluate the thermal-optical performance of a kinematic mounting applied in lithographic projection lens, the optical surface figure and wavefront changes of the lens element under a certain thermal load are investigated with both experimental and numerical simulation methods. From the experimental and numerical results, the temperature on the edge of the lens element rises up to 22.51°C, and the center of lens is 5.3°C higher. As a result, this thermal nonuniformity leads to a 9.622 nm RMS change of the optical surface figure and 71.905 nm RMS change of the index inhomogeneity, consisting mainly of Z4, Z9, and Z16. Because of the radial flexibility of the supporting legs of the kinematic mounting, aberrations such as pri trefoil and sec trefoil are less than 2% of the total wavefront changes, and other nonaxisymmetric aberrations are negligible. The Zernike coefficient differences between experiments and simulation are less than 2 nm, which supports the correctness of our method. The kinematic mounting shows good thermal adaptability, and the method for evaluation of the thermal-optical characteristics is proved effective.
Static compression test on the Honeycomb sandwich structure with surface core defect carry out in this paper. The specimen divided into four groups, one had no defect, one had circle defect, the other two groups had rectangular defect in different direction. In the process of loading the strain gauge which located on the specimen surface in each group record the strain transformation of the specimen surface. Through the Static load test on the fatigue testing machine, fracture load of each specimen was record. According to the data, how the size and shape of the defect influence the compression static strength of Honeycomb sandwich was discussed, and inspecting defects direction how to affect the structural static strength by means of theoretical analysis and data fitting, meanwhile the shape of the defects in structure how to effect buckling was discussed too.
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