Journal Article Research Support, Non-U.S. Gov't Research Support, N.I.H., Extramural X-ray deformable mirrors X-ray diffraction imaging X-ray free-electron laser X-ray optics apodized X-ray illumination beam divergence beamline development biological cells brain imaging cryogenic experiments data acquisition system hard X-ray microscopy hard X-ray photoelectron spectroscopy high-resolution X-ray imaging microtomography shot-to-shot measurement soft X-ray photoelectron spectroscopy tomography