SOLEX:: a tunable monochromatic X-ray source in the 1-20 keV energy range for metrology

A tunable monochromatic X-ray source covering the 1-20 keV energy range is described. The initial X-ray beam is obtained. from a dedicated windowless X-ray tube. The energy selection is performed through a cylindrically bent crystal, used either in the reflection (Johann geometry) or in the transmission (Cauchois geometry) mode, by rotating the crystal holder by a 90degrees angle. Contrary to conventional geometries where the X-ray tube is fixed, here the direction of the exit beam impinging the X-ray detector is fixed. This setup is shown to be useful for various studies: high-resolution spectrometry, characterization of the response function and the efficiency of detectors and optical components, determination of transmission characteristics of different materials. Observations of the Lalpha line and Kalpha. doublet from a copper anode are presented, that demonstrate the performance of this new setup. (C) 2003 Elsevier B.V. All rights reserved.