Graded multilayers for figured Kirkpatrick-Baez mirrors on the new ESRF end station ID16A

The upgraded ESRF end station ID16A was equipped with a new Kirkpatrick-Baez (KB) nano-focusing setup. The figured KB mirrors were coated with steeply graded W/B4C multilayers to account for the variable angle of reflection along the beam footprint. The multilayers were deposited at the ESRF Multilayer Facility by DC magnetron sputtering in dynamic mode, where the substrates move in front of the sputter cathodes. The present work deals with the design, the fabrication, and the characterization of the coatings. First results obtained during commissioning experiments on ID16A complement the report.