At-wavelength metrology using the X-ray speckle tracking technique: case study of a X-ray compound refractive lens

The X-ray speckle tracking technique has been established on the Test beamline B16 at Diamond and is being used as a valuable tool for at-wavelength metrology. We show here the possibilities and the achievable performances of the X-ray Speckle Tracking technique for optics characterization: the description is illustrated with the case study of the characterization of a compound refractive lens. This optical element was characterized online using the speckle tracking method with nanoradian accuracy and micrometer spatial resolution. For discussion purpose, the results are compared to the ones obtained under similar conditions using a grating interferometer.