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.

We describe an instrument designed for studying the electronic structure of bulk, surface, and deep solid–solid interface. The analysis is made by soft-x-ray emission spectroscopy induced by electron bombardment. The target is placed under ultrahigh vacuum and can be prepared and treated in situ. High resolution is achieved both as concerns the photon energy and the electron-beam energy. Tests have been made in the dispersive mode and in the characteristic isochromat mode. In both cases experimental resolution is in good agreement with the expected one.

A high resolution, curved-crystal spectrometer of compact design is described. It can be adapted to any X-ray source and covers the 0.5 to 10 nm wavelength range. The scanning of spectra is obtained by means of a novel mechanical arrangement using two coaxial rotary stages and a system of rotating arms. (patent nr 86.08871). The step-by-step scanning of spectra is driven by an Apple Ile microcomputer which is also used to perform the data acquisition for X-ray emission, X-ray absorption and isochromat spectra.

An x-ray spectrometer based on the Johann bent-crystal principle is described. An entrance slit system has been adopted which provides excellent protection of the diffracting crystal from metallic vapors. Such an arrangement also provides improved resolution and dispenses with the need for a thin film window between the x-ray source and spectrometer tank. Resolution comparable to a two plane-crystal instrument has been attained and systematic studies of the soft x-ray emissions from liquid metals and alloys and metallic vapors undertaken.