Soft X-ray spectroscopy in the lab with an ellipsoidal mirror and a wavefront corrected reflection zone plate

Abstract

We present first experimental results on wavelength-dispersive soft X-ray spectroscopy of TiO2 in the vicinity of the Ti Lσ fluorescence line with a central energy of about 452.2 eV, demonstrating the functionality of a newly developed, laboratory-scaled setup. In our instrument, the micron-sized photon emission from an electronexcited source is collected efficiently by a rotationally symmetric, ellipsoidal mirror and subsequently dispersed by a reflection zone plate with inscribed diffractive wavefront correction, to compensate for figure and alignment errors of the ellipsoid to some degree. The measured data, recorded with a CCD camera in one meter from the source, show clearly separated peaks from different Ti L (398.3 eV and 452.2 eV) contributions and O Kα emission (523.1 eV) with an energy resolving power around 38 and a signal-to-noise ratio between 4.4 and 10.7.