Development of X-ray Wavefront Sensing Techniques for Adaptive Optics Control at the Advanced Photon Source

Introduction The planning and construction of new and upgraded high-brightness X-ray synchrotron and free electron laser sources, such as the Advanced Photon Source upgrade project (APS-U) [1], are driving numerous opportunities to advance X-ray science and technologies. At the same time, an increasing number of highly diverse beamline experiments demand wavefront-preserving adaptive X-ray optics with both high precision and flexibility. At the APS, significant effort has been devoted to developing next-generation adaptive and corrective optics combined with state-of-the-art at-wavelength wavefront sensing techniques and an intelligent feedback control system for the automation and self-alignment of beamline optical systems. This article reviews recent achievements in these areas at the APS [2–11]. These include the development of in-situ wavefront sensing [2, 3], the application in active feedback control of ultra-precision deformable mirrors [4, 5], and the exploration of non-invasive wavefront sensing techniques for adaptive optics and beamline diagnostics [6–8].