The driving science of X-ray all-sky monitoring calls for new generation instruments with high sensitivity, good angular resolution (a few arc-minutes or less) and a large sky coverage (field of view of order of thousands square degrees). These requirements can be fulfilled by wide-field X-ray focusing optics—the emerging lobster-eye Micro-Pore Optics (MPO), whose focusing imaging results in enormously enhanced gain in signal to noise, and hence high detecting sensitivity. EP carries a Wide-field X-ray Telescope (WXT) with a large instantaneous FoV, which adopts such a novel lobster-eye MPO technology.  Complementary to this wide-field instrument is a Follow-up X-ray Telescope (FXT) with a large effective area and a narrow field-of-view. Figure 1 shows a possible configuration of the EP payload.


  Figure 1 Preliminary configuration of the EP payloads alignment, with twelve WXT modules surrounding two FXT telescopes.