Electroforming replication technology at the Marshall Space Flight Center has a long heritage of producing high-quality, full-shell X-ray mirrors for various applications. Nickel alloys are electroformed onto a super-polished mandrel in the electroforming process and then separated to form the replicated full-shell optic. Various parameters in the electroplating configuration could result in the non-uniformity of the shell’s thickness. Thickness non-uniformities primarily occur due to the non-uniform electric field distribution in the electroforming tank during deposition. Using COMSOL Multiphysics simulations, we studied the electric field distributions during the deposition process. Using these studies, we optimized the electric field distribution and strength inside the tank using customized shields and insulating gaskets on the mandrel. These efforts reduced the thickness non-uniformity from over 20% to under 5%. Improving the thickness uniformity of the shell aids in better mounting and aligning shells in the optics module. Optimization of the electroforming process, in some cases, improved the optical performance of the shells. Using finite element modeling, we estimated the effect of electroforming stress on the figure errors of the replicated optics. We observed that the electroforming stress predominantly affects the figure toward the ends of the optics. We presented COMSOL optimization of the electroforming process and the experimental results validating these simulations. We also discuss modeling experimental results of the replication figure errors due to electroforming stresses.

中文翻译：

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优化全壳 X 射线光学器件的电铸工艺


马歇尔太空飞行中心的电铸复制技术在生产适用于各种应用的高质量全壳 X 射线镜方面拥有悠久的历史。在电铸过程中，镍合金被电铸到超抛光的心轴上，然后分离以形成复制的全壳光学器件。电镀配置中的各种参数可能会导致外壳厚度的不均匀性。厚度不均匀性主要是由于沉积过程中电铸槽内电场分布不均匀造成的。使用 COMSOL Multiphysics 模拟，我们研究了沉积过程中的电场分布。通过这些研究，我们使用心轴上的定制屏蔽和绝缘垫圈优化了罐内的电场分布和强度。这些努力将厚度不均匀性从超过 20% 降低到 5% 以下。提高外壳的厚度均匀性有助于更好地安装和对准光学模块中的外壳。在某些情况下，电铸工艺的优化可以提高壳体的光学性能。使用有限元建模，我们估计了电铸应力对复制光学器件的形状误差的影响。我们观察到电铸应力主要影响光学器件末端的形状。我们介绍了电铸过程的 COMSOL 优化以及验证这些模拟的实验结果。我们还讨论了电铸应力引起的复制图形误差的建模实验结果。