SMART: A planned ultrahigh-resolution spectromicroscope for BESSY II

A new UHV spectromicroscope called SMART (spectromicroscope for all relevant techniques) is currently under construction for a soft X-ray undulator beamline at BESSY II. The instrument consists of a plane-grating monochromator with an aspherical focusing mirror and an ultrahigh-resolution, low-energy electron microscope containing an energy filter. It can be used as a photoemission microscope for a variety of electron spectroscopies (XAS, XPS, UPS, XAES) and has a calculated spatial resolution of better than 1 nm. A maximum energy resolution of about 0.1 eV will be provided by a corrected omega filter. The high lateral resolution of the electron microscope will be achieved through the correction of the chromatic and spherical aberrations of the objective lens by means of an electrostatic mirror in combination with a corrected magnetic beam separator, An additional electron source placed on the other side of the beam separator opposite the electrostatic mirror will also allow LEEM, MEM and small-spot LEED investigations to be carried out. The basic ideas, the various modes of operation and the electron optical design of the instrument are outlined. (C) 1997 Elsevier Science B.V.