New lens for a lowhyphen;voltage scanning electron microscope

摘要

This article introduces the idea of a lsquo;lsquo;halfthinsp;rsquo;rsquo; polehyphen;piece to modify single polehyphen;piece lenses, enabling them to form an electron probe a few millimeters in front of the pole face. This modified single polehyphen;piece lens has relatively low spherical and chromatic aberration coefficients. If 2 mm is an acceptable working distance, then a 6hyphen;Aring; radius probe can be made using 5hyphen;kV electrons.