Some applications of nanometer scale structures for current and future X-ray space research

Nanometer scale structures such as multilayers, gratings and natural crystals are playing an increasing role in spectroscopic applications for X-ray astrophysics. A few examples are briefly described as an introduction to current and planned applications pursued at the Danish Space Research Institute in collaboration with the FOM Institute for Plasma Physics, Nieuwegein, the Max-Planck-Institut für Extraterrestrische Physik, Aussenstelle Berlin, the Space Research Institute, Russian Academy of Sciences, the Smithsonian Astrophysical Observatory, Ovonics Synthetic Materials Company and Lawrence Livermore National Laboratory. These examples include : 1. the application of multilayered Si crystals for simultaneous spectroscopy in two energy bands one centred around the SK-emission near 2.45 keV and the other below the CK absorption edge at 0.284 keV; 2. the use of in-depth graded period multilayer structures for broad band spectroscopy in the energy range up to 100 keV; 3. the potential use of large perfect asymmetrically cut Si or Ge crystals combined with a short focal length multilayer telescope for ultra high energy resolution solar/stellar spectroscopy with $E/\Delta E > 10^4$ and; 4. high throughput multilayer coated telescope for high resolution Fe K line spectroscopy with microcalorimeters.