July 2008 issue
Cover illustration: Schematic of a scanning X-ray microprobe with a segmented transmission detector (see Hornberger, de Jonge, Feser, Holl, Holzner, Jacobsen, Legnini, Paterson, Rehak, Strüder and Vogt, pages 355-362). Three different segmentations are shown on the left. The difference signal between opposing segments measures beam deflections and therefore phase gradients in the specimen. The bottom figures illustrate the difference between absorption contrast (total transmitted intensity) and differential phase contrast (difference of opposing segments) for a cardiac myocyte imaged at 10 keV photon energy, and a diatom imaged at 1.79 keV.