RECENT DEVELOPMENTS OF MULTILAYER
Optics for X-ray Diffractometry

A. Bauer, C. Michaelsen, A. Oehr, C. Hoffmann, J. Wiesmann

Incoatec GmbH, Max-Planck-Strasse 2, D-21502 Geesthacht, Germany

We present our recent developments of one-dimensional parabolic X-ray optics for parallel beam X-ray Diffractometry (XRD), especially for high resolution applications and reflectometry, and two-dimensional focusing X-ray optics for Single Crystal Diffractometry (SCD). You will get information on what kind of multilayer optics you could use or not for your application.

For XRD the so-called Göbel-Mirrors convert the X-ray beam coming from an X-ray tube into a monochromatic parallel beam. The mirrors consist of multilayers with laterally graded thickness, deposited extremely accurately onto a parabolic surface. Significant intensity gain was achieved using these X-ray mirrors in High Resolution Diffractometry (HRXRD) and X-ray Reflectometry (XRR). This was made possible by the development of the so-called 3^rd generation GM’s. These 3^rd generation GM’s consist of an ultra-precise prepolished parabolical form (with slope errors down to 1 arcsec rms) coated with an ultra-precise multilayer mirror. The talk addresses fabrication, characterization and optimization of different types of Göbel Mirrors with respect to special applications and XRD set-ups.

Our optics for SCD consists of elliptical multilayer mirrors with laterally graded thickness of the layers. They are now available for different wavelengths such as Cr, Fe, Cu and Mo.

The talk will show design, simulations and properties of the 2-D optics illustrating their advantage in the field of many different crystallography applications. We obtained flux densities above 10¹⁰ photons/s/mm² at beam diameters below 0.3 mm. Small crystals with sizes below 50 microns can now be analyzed by SCD in lab-instruments.