Ellipsoidal mirrors are promising optical devices for soft x-ray focusing. A fabrication process consisting of master fabrication and replication has been developed to produce ellipsoidal mirrors with wide apertures of approximately 10 mm. In the present study, the focusing performance of an ellipsoidal mirror was evaluated using soft x-rays in the soft x-ray beamline BL25SU-a of SPring-8. The focus sizes were measured at photon energies of 300, 400, and 500 eV. A quantitative figure error of the ellipsoidal mirror was also evaluated by analyzing the wavefield of the focused beam retrieved using ptychography. The figure error distributions measured at different photon energies agreed with each other at a root mean square level of 1 nm. The developed focusing system can be used for various types of microscopy, allowing the use of a wide range of x-ray energies.

中文翻译：

---

由椭球镜形成的软 X 射线纳米束

椭球镜是用于软 X 射线聚焦的有前途的光学设备。已经开发出由母版制造和复制组成的制造工艺来生产具有大约 10 毫米宽孔径的椭球镜。在本研究中，使用 SPring-8 的软 x 射线束线 BL25SU-a 中的软 x 射线评估椭球镜的聚焦性能。在 300、400 和 500 eV 的光子能量下测量焦点尺寸。通过分析使用 ptychography 检索到的聚焦光束的波场，还评估了椭球镜的定量图形误差。在不同光子能量下测量的图形误差分布在 1 nm 的均方根水平上彼此一致。开发的聚焦系统可用于各种类型的显微镜，