A new laboratory apparatus devoted to the characterization of various devices for the X-UV range ( 100 - 5000 eV), such as mirrors, diffraction gratings, spectrometers or detectors is described. The apparatus includes open X-ray tubes as X-ray sources, a two-crystal monochromator for wavelength selection and a goniometer. Various examples of its use are presented: dispersive mode where the radiation coming from the X-ray tube is dispersed by the two-crystal monochromator, spectrometric mode where the goniometer is used as a plane X-ray spectrometer and reflectometric mode where a selected wavelength is used to perform absolute reflectivity measurements.

The design of efficient lamellar multilayer amplitude grating (LMAG) monochromators in terms of bandwidth and peak reflectivity for the soft-X-ray domain, covering the K emission of low atomic-number elements: B to Si, is considered. A Mo/B4C LMAG suited for spectrometry in this spectral domain has been designed, fabricated using electron beam lithography together with reactive ion etching and tested with success.

Un spectrogoniometre de laboratoire utilisant comme source un tube emettant des radiations caracteristiques dans le domaine X mou et X-UV a ete developpe au Laboratoire de Chimie Physique (CNRS/UPMC) dans le cadre de l'Action Coordonnee Optique du CNRS. L'appareil comprend un monochromateur de type double-cristaux equipe de miroirs multicouches ou de cristaux de grande periode et un goniometre θ-2θ. Il permet des mesures de pouvoir reflecteur et de diffusion de dispositifs optiques, en particulier de miroirs et reseaux multicouches. Dans un futur proche il sera aussi destine a la caracterisation de nouvelles sources et de detecteurs X-UV. L'appareil peut aussi etre utilise comme spectrometre a cristal plan si l'anode est remplacee par l'echantillon a analyser. Differents exemples des possibilites offertes par cet instrument operant en mode reflectometrie ou en mode spectrometrie sont presentes.

The principle of a multilayer monochromator with a narrow bandwidth and a low specular background is recalled. The elaboration of such a monochromator obtained from a Mo/Si multilau-yer mirror is briefly described. The performance of the device measured at 1500 and 98 eV is presented. Le principe d'un monochromateur multicouche a bande passante etroite et presentant un faible fond continu est rappele. Nous decrivons brievement la fabrication d'un tel monochromateur obtenu a partir d'un miroir multicouche Mo/Si. Les performances de ce dispositif mesurees a 1500 et 98 eV sont presentees.

An x-ray multilayer monochromator with improved resolution and a low specular background is presented. The monochromator consists of a lamellar multilayer amplitude grating with appropriate parameters used at the zeroth diffraction order. The device is fabricated by means of combining deposition of thin films on a nanometer scale, UV lithography, and reactive ion etching. The performance of this new monochromator at photon energies near 1500 eV is shown.

A new soft-x-ray multilayer monochromator with an improved resolution and a low specular background is presented. The principles of the device, based on the use of a lamellar multilayer amplitude grating (LMAG), are summarized. The techniques of fabrication of the monochromator (multilayer deposition, UV lithography and reactive ion etching) are given. The performance of this new monochromator at photon energies around 1500 eV is demonstrated. Copyright © 2001 John Wiley & Sons, Ltd.

A new kind of xuv multilayer monochromator with a narrow spectral bandwidth is introduced. This monochromator is based on a Mo/Si multilayer mirror etched according to the profile of a lamellar grating. The fabrication of such a device involving multilayer deposition, UV lithography and reactive ion etching is presented. The monochromator has been characterized by means of the synchrotron radiation around the Si–L edge (100 eV). A reduction of the bandwidth has been observed with respect to the unpatterned mirror by a factor close to 3.

The effects of continuous thermal annealing on the performances in terms of reflectivity of Mo/Si, Mo/C, Ni/C multilayer mirrors are studied. The measurements of reflectivity around 100eV are performed by using the synchrotron radiation supplied by Super-AGO at the LURE. Variations of reflectivity versus the temperature are recorded. We observe that the period of the Mo/Si mirror decreases, the one of the Mo/C mirror remains constant and the one of the Ni/C increases as the annealing temperature increases. These behaviours are discuted in the framework of material science.

We realized a laterally-d graded multilayer interference mirror using a special configuration of a sputtering deposition system. Metrology of this device was done (we have found the variation of period versus the lateral position) on the SB3 beamline, a CEA calibration station located at the 'Laboratoire pour l'Utilisation du Rayonnement Electromagnetique' in Orsay.A wide set of applications was shown by studying transmission of X-ray radiation transmitted through copper metal foil, especially spectral analysis in the L absorption edge.This analysis was simply realized by translating the laterally-d graded multilayer interference mirror at a fixed glancing angle. (C) 1999 Elsevier Science B.V. All rights reserved.

A partir de mesures de réflectivité spéculaire en rayons X rasants, 1' épaisseur d'une couche mince de carbone déposée sur un substrat de verre a été déterminée.La méthode consiste à effectuer une transformation de Fourier de la réflectivité mesurée en fonction de l'angle d'attaque, ce qui permet d'atteindre fa fonction d'autocorrélation du profil d'indice optique et d'en déduire I'épaisseur de la couche superficielle.L'épaisseur déterminée par cette technique est de 120 nm, pour une épaisseur nominale de 100 nm.

Optical constants of amorphous have been calculated by the Kramers-Kronig analysis in the continuous spectral region including , O K and Si K absorption edges from the reflection spectra measured using synchrotron radiation. It is the first experiment carried out in such a wide energy region with the same sample. It has been found that for extrapolation of the experimental curve in the high energy region, where the photon energy exceeds the ionization potential of the Si K edge, the relation can be used for energies such that at small grazing angles.

The concept of X-UV Lamellar Multilayer Amplitude Grating (LMAG) is introduced and a method of fabrication is given. Dynamical and kinematic theories of the diffraction by a LMAG are presented. Different applications of the LMAGs are considered. The first one is the achievement of a narrow bandpass multilayer monochromator for the X-UV domain. The second one is the reduction of specular background in the reflectivity curve of a multilayer structure. The third one is the polychromator system which allows one to split spatially and to perform a spectral sampling of a polychromatic beam. Finally we studied experimentally the behavior of an LMAG in conical mounting.

Nous avons etudie l'effet d'une elevation de temperature sur les performances optiques dans le domaine X d'un miroir multicouche interferentiel Mo/Si. L'empilement multicouche realise par pulverisation magnetron a ete chauffe a differentes temperatures comprises entre la temperature ambiante et 500°C. Nous avons observe une diminution de la periode, une substantielle reduction de la reflectivite pic accompagnees d'un elargissement de la bande passante ainsi qu'une modification structurale. Ces effets sont interpretes comme la consequence de la formation d'une couche interfaciale cristallisee sous forme de MoSi 2 hexagonal.

We propose a method to reduce the bandpass of soft x-ray multilayer Bragg reflectors. It consists in etching down to the substrate a multilayer mirror having a large number of bilayers in order to get a lamellar grating with a multilayer bar width representing only 10%–30% of the grating period. The grating is used at the zeroth diffraction order. Once designed, this monochromator was tested with the Lα,β spectra of iron and copper.

Le principe de la diffraction par un réseau lamellaire gravé dans miroir multicouche est exposé.Un tel réseau a été réalisé en combinant les techniques de

We present experimental and theoretical studies of the diffraction by an x-ray lamellar multilayer amplitude grating. The main diffraction properties of such a device are given. Experimental efficiency curves are obtained at 800 eV photon energy using synchrotron radiation. The features observed in these curves are identified and interpreted by means of two theoretical methods. Particular emphasis is given to structures observed for the first time which had been theoretically predicted.

The damage induced to various multilayer interferential mirrors (MIMs) by intense soft X-ray plasma-laser sources are studied both experimentally and theoretically. The mirrors consist of periodic bilayers made up with C/W, Si/Mo, Si/W\. One set of Si/W MIMs is coated with a 100 nm Si film devised to protect the multilayer structure. In the experiment, one resolves in time the evolution of the diffraction pattern of a MIM illuminated by the radiation of a NaCl probing laser-plasma and exposed to the heating radiation emitted by a gold laser-plasma. One measures the damage threshold time and the damage threshold fluence. Simulations are performed by combining an optical code with a Lagrangian thermomechanical code giving at each time the density and the thickness of each layer in the MIM.

An experimental study of the diffraction of X rays in the keV region by a lamellar multilayer amplitude grating is described. This optics is obtained by periodic etching of an interferential multilayer mirror down to the substrate. The advantages provided by the etching to the system response and its use as an energy separator are given.

The influence of the number of bilayers on the optical performances of actual X-UV multilayer interferential mirrors (MIMs) has been studied in order to emphasize the experimental restrictions in the designing of "thick" mirrors used for the development of etched multilayer gratings. Several sets of samples (W/C, Mo/Si) with increasing number of bilayers have been manufactured in the very same conditions by means of a sputtering technique. X-ray diffraction characterization at Cu-Kα radiation (λ = 1.54018 Å) exhibits technical constraints in the achievement of multilayer structures with large number of bilayers. We obtain a gradual loss of reflectivity for deposition times greater than 1h 30 min to 2h without significant drift of the MIM's geometrical parameters (period and division parameter). In the same time, absolute reflectivity measurements at Cu-Lα radiation (λ = 1.333 nm) emphasize satisfying optical and spectroscopic performances of W/C thick samples ( 150 bilayers).