Design features of a new ultra-high vacuum electron microscope with an omega filter

An ultra-high vacuum high-resolution electron microscope for surface and in terface structure studies was newly designed and constructed. Two new appro aches were adopted together with a field emission gun. One is to introduce an omega-type energy filter system that enables us to obtain energy-filtere d diffraction patterns and images in transmission and reflection electron m icroscopy for well defined surfaces. The other is to combine a unit of spec imen treatment chambers. Design features and some results are described.