Optics on a synchrotron radiation soft X-ray microscopy beamline and its dispersing components in Hefei

A modified optical design for a synchrotron radiation (SR) soft X-ray scanning microscopy beamline at Hefei National Synchrotron Radiation laboratory (HESYRL) has been done. On the beamline the main component is a linear monochromator which consists of a diaphragm with a diameter of 7 µm and a condenser zone plate (CZP). The CZP is selected from among three condenser zone plates with different parameters for the following three overlapping wavelength ranges: 1.97-2.78 nm, 2.74-3.87 nm, and 3.84-5.44 nm. Estimating the flux losses from the pinhole source to the end spot for 2.3 nm, for example, a photon flux of 3.1 × 10⁵ photons/s can be achieved at the end spot from a 150 mA current and a high brightness configuration at HESYRL.

Parameters of three kinds of CZPs are presented as a compromise to a variety of requirements from the experimenters. In addition, the thickness of some CZP layers, such as polyimide and gold, are calculated to be optimal. Finally, the processing steps for CZP fabrication at HESYRL are described briefly.