A NEW METHOD FOR LOW-MAGNIFICATION IN THE ENVIRONMENTAL SCANNING ELECTRON-MICROSCOPE

A device has been developed and used successfully on two models of the environmental scanning electron microscope that allows low-magnificat ion imaging of about 30x, significantly better than the original 200x low-magnification imaging limit. This was achieved by using an additio nal aperture to limit the pressure at a point where it will not block the electron beam, and a larger aperture plate for the combination fin al aperture/secondary electron signal collection surface that also doe s not block the electron beam significantly.