SMART - A PLANNED ULTRAHIGH-RESOLUTION SPECTROMICROSCOPE FOR BESSY-II

A new UHV spectromicroscope called SMART (spectromicroscope for all re levant techniques) is currently under construction for a soft X-ray un dulator beamline at BESSY II. The instrument consists of a plane-grati ng monochromator with an aspherical focusing mirror and an ultrahigh-r esolution, low-energy electron microscope containing an energy filter. It can be used as a photoemission microscope for a variety of electro n spectroscopies (XAS, XPS, UPS, XAES) and has a calculated spatial re solution 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 res olution of the electron microscope will be achieved through the correc tion of the chromatic and spherical aberrations of the objective lens by means of an electrostatic mirror in combination with a corrected ma gnetic beam separator, An additional electron source placed on the oth er side of the beam separator opposite the electrostatic mirror will a lso allow LEEM, MEM and small-spot LEED investigations to be carried o ut. The basic ideas, the various modes of operation and the electron o ptical design of the instrument are outlined. (C) 1997 Elsevier Scienc e B.V.