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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2009

Portland State University

Theses/Dissertations

Electrostatic lenses

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Full-Text Articles in Physical Sciences and Mathematics

Comparison Of The Focal Properties Of Selected Magnetic And Electrostatic Lenses And Tests Of Their Theoretical Models, Luis Thomas Almarez Jun 2009

Comparison Of The Focal Properties Of Selected Magnetic And Electrostatic Lenses And Tests Of Their Theoretical Models, Luis Thomas Almarez

Dissertations and Theses

The main goal of the present research is to determine whether there is a significant difference between the aberrations of magnetic and electrostatic electron lenses when they are used in the same way. Comparison of the lenses was done in an electron-optical bench, set up to resemble a scanning electron microscope (SEM). Five different lenses, two magnetic and three electrostatic, were compared. Each group included two lenses with different lens-field lengths (pole-face spacing in magnetic lenses and interior length in electrostatic lenses). The lenses were used in turn to focus the electron beam into a demagnified image, or probe. The …