Conceptual Design of TXM Beamline at High Energy Photon Source

. As one of the HEPS project beamlines, zone plate based full-field transmission x-ray microscopy (TXM) beamline will provide imaging tool with spatial resolution down to 20nm and exposure time of sub-second, along with different imaging mode such as absorption, Zemike phase and XANES. Because HEPS will operate a nearly diffraction limited storage ring (less than 60pm"rad), how to utilize the feature of low emittance becomes interesting and it is some challenging to satisfy the zone plate imaging with enough illumination angle and field-of-view. Within the optimized conceptual design, beam shaper condenser instead of capillary was selected to focus x-rays to sample and give enough illumination angle to zone plate, and red-shift undulator radiation was used to improve beamline efficiency.