Concept and Design of the SMART Spectormicroscope at BESSY II

摘要

The concept of a new spectromicroscope (SMART=spectromicroscope for all relevant techniques) currently under construction for an undulator beam line at BESSY II is discussed. The design of the optical system is described as well as the modes of operation and the experiments that can be performed. Monochromatic XUV-radiation (tunable within the energy range 20 to 2000 eV) will be provided by a planegrating monochromator and focussed onto the sample by means of an ellipsoidal mirror. In addition, an electron gun will be installed allowing LEEM, MEM and other forms of microscopy as well as small spot LEED to be performed. With an aberration corrector we expect to achieve a lateral resolution better than 5 nm and to increase considerably the transmission of the optical system compared to previous instruments. An imaging band pass filter corrected to second order will select the energy and the energy band width for the image-forming electrons. The instrument will also allow spectroscopy of photoelectrons from selected small areas of the sample (5-500 nm) with an energy resolution of 0.1 eV.