A novel imaging x-ray microscope based on a spherical crystal

      M. Sanchez del Rio 
      European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France 

      L. Alianelli 
      INFM-OGG c/o ESRF, BP 220, F-38043 Grenoble Cedex, France 
      ILL, BP 156, F-38042 Grenoble Cedex, France 

      T. A. Pikuz and A. Ya. Faenov 
      Multicharged Ions Spectra Data Center of National Research Institute for Phyiscal-Technical and Radiotechnical Measurements VNIIFRTI, Mendeleevo, Moscow Region 141570,
      Russia 

(Received 25 October 2000; accepted 22 April 2001) 

A novel, compact, large field, and spectrally tunable imaging x-ray microscope is presented. It is based on the use of an isotropic point x-ray source and a spherically
curved crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized and enlarged using a spherical crystal and, finally, imaged using a
detector downstream from the crystal. We demonstrate by ray tracing simulations that this system allows microscopy studies with high spatial resolution, high
magnification ratios, and large field of view. Microscopes using this model can be easily built using different x-ray sources, like conventional x-ray tube generators, x rays
emitted by laser-generated plasmas or x-pinch plasmas, and also synchrotron radiation when used in combination with other condenser optics. Preliminary experiments
are presented to demonstrate the feasibility of the proposed setup. High resolution (~4 µm) monochromatic (/~10-5-10-3) images over a large field of view (few
mm2) were recorded in the spectral range 8-14 Å using a laser-generated plasma source and a spherical mica crystal. Compared to x-ray crystal imagers used in
relation with plasma sources, the new configuration produces high quality stigmatic images working at many different Bragg angles, thus improving the spectral tunability
and allowing a more flexible design. ©2001 American Institute of Physics.