基于光谱共焦探针的Wolter-Ⅰ型X射线显微镜芯轴高精度检测

High-precision measurement of Wolter-I mandrel for X-ray microscopy by using double confocal probes

Wolter型X射线显微镜具有高分辨率和集光区域,在先进光源和高能激光器中有重要的应用价值。基于镍电镀成形的复制法是制备Wolter型X射线显微镜的有效方法之一,其中,芯轴的表面精度和质量会直接影响X射线成像的性能。高精度检测技术是芯轴制备的基础,而传统检测装置难以测量具有圆周回旋对称特征的Wolter型表面轮廓。为了解决Wolter型芯轴检测难和测量精度低的问题,搭建了基于光谱共焦探针的离线检测装置实现芯轴表面中低频轮廓的高精度测量,分析了该装置的各类系统误差和随机误差,并采用双探针与标准镜来校准测试过程,将测试中的温湿度漂移和随机误差的PV值降低至23 nm。最后,开展了该检测装置和CGH干涉检测法的检测对比实验。通过Wolter芯轴表面测试结果比较,两种测试方法的偏差PV值约为60 nm,证明了该检测装置的合理性和检测方法的准确性。

The Wolter-type X-ray microscope,known for its high resolution and collecting area,is replac⁃ing KB-type X-ray microscopy in advanced light sources and high-energy lasers.A notable method for fab⁃ricating Wolter-type X-ray mirrors is nickel electroforming,where the surface accuracy and quality of the replication mandrel crucially impact mirror performance.Preparing the mandrel requires high-precision in⁃spection technology,yet traditional equipment struggles to measure the circumferentially symmetric sur⁃face profile of the Wolter type.To address this challenge,we developed an offline detection device using a non-contact probe to measure the mandrel′s middle and low frequency surface profile.Systematic and ran⁃dom errors in the detection device were analyzed,and we employed a dual-probe calibration method with a standard mirror,reducing the peak-to-valley(PV)value of drift due to temperature and humidity to 23 nm.A comparative experiment between our detection device and the CGH interferometric detection method showed a deviation of approximately 60 nm in the PV value of the surface test results for the Wolter man⁃drel,validating the effectiveness and accuracy of our detection method.