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Full-Text Articles in Physics
Aberration Corrected Photoemission Electron Microscopy With Photonics Applications, Joseph P. S. Fitzgerald
Aberration Corrected Photoemission Electron Microscopy With Photonics Applications, Joseph P. S. Fitzgerald
Dissertations and Theses
Photoemission electron microscopy (PEEM) uses photoelectrons excited from material surfaces by incident photons to probe the interaction of light with surfaces with nanometer-scale resolution. The point resolution of PEEM images is strongly limited by spherical and chromatic aberration. Image aberrations primarily originate from the acceleration of photoelectrons and imaging with the objective lens and vary strongly in magnitude with specimen emission characteristics. Spherical and chromatic aberration can be corrected with an electrostatic mirror, and here I develop a triode mirror with hyperbolic geometry that has two adjacent, field-adjustable regions. I present analytic and numerical models of the mirror and show …
Electron Optical Study Of A Secondary Electron Multiplier, Chang Min Shen
Electron Optical Study Of A Secondary Electron Multiplier, Chang Min Shen
Dissertations and Theses
Electron orbital theory was applied to the design of the geometrical structure of an electron multiplier for an image intensifier. A special structure satisfying production requirements was studied. Electron optical calculations consisted of determining the potential distribution and tracing the electron trajectories. Liebmann's procedure was used to solve Laplace's equation with constant potentials on the multiplier electrodes as boundary conditions. The trajectories were determined by solving the equation of motion in an electrostatic field using a Runge-Kutta procedure. The initial conditions for the trajectories were the initial energies, initial positions, and the initial directions of the secondary electrons. The plotted …