The Influence of Bores Diameter on the SEM's Objective Lens Properties
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Abstract
In a previous study, a new design of a magnetic objective lens had been chosen among five new designs as the preferred one. Both of the iron shroud and polepiece bore diameters of the preselected lens have been changed and studied in this work to improve its magnetic and optical properties. An extensive investigation has been done to analyze the magnetic field distribution, magnetic flux density, and optical properties for each model using the finite element method (FEM) with the computer-aided programs. All the analyses have been carried out at the same coil excitation (NI = 10 kA.t). The new improved design yield here will be prepared to fabrication to be used as an objective lens for the SEM.
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