Direct observation of insulators with a scanning electron microscope

Abstract
A low energy electron gun is used to discharge insulating specimens during observation with a scanning electron microscope. The apparatus includes essentially the gun, an optical microscope, a supplementary grid before the electron detector, and a video signal chopper. Either topographic, chemical, crystallographic or potential contrasts can be observed with a high energy (30 keV) electron probe; observation of insulators under deformation is possible.