Construction and design of a high resolution portable scanning electron microscope column

Abstract

This paper presents Hall probe measurements on the recently proposed high resolution portable Scanning Electron Microscope (SEM) concept. A test column using permanent magnet lenses was constructed and has a height of 120 mm. Experimental axial flux density measurements were found to correlate well with simulation predictions. A method of varying the axial field strength by using magnetic shorting plates was investigated and found to be successful. In this way, the beam energy can be varied, and the portable permanent magnet column will be able to operate in a similar way to conventional SEMs.