Versatility of a hard X-ray Kirkpatrick-Baez focus characterized by ptychography

J. Synchrotron Rad. (2013). 20, 490-497 (http://doi.org/mvf)

In the past decade Kirkpatrick-Baez (KB) mirrors have become an increasingly popular tool for efficient focusing of high-power third-generation synchrotron beams. Taking the dedicated nano-imaging setup GINIX (Göttingen Instrument for Nano-Imaging with X-rays) at the P10 beamline of the PETRA III synchrotron in Hamburg, Germany, as an example, the versatility of such a focusing device has been explored. By full characterization of the complex focal wave field using ptychography it is shown how a spatial filter near the focal plane can be used to obtain a nearly Gaussian focus with a smooth far-field intensity distribution. The focal size is shown to be precisely adjustable by variation of the entrance aperture.