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Electron Sources and Column Components for Ultrafast Electron Microscopy

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thesis
posted on 01.11.2017 by Benjamin L Rickman
Ultrafast Electron Microscopy (UEM) is a promising new research instrumentation for the material sciences that is targeted towards improving the combined spatial and temporal resolution of measurement techniques. The applicability of UEM hinges on the quality of the pulsed electron source generated from a laser-driven photoelectron gun. Detailed knowledge of the photoemission mechanism provides a correlation between the characteristics of the photocathode and pulsed electron beam and therefore a path towards the ideal photocathode material. Improvement of this critical component will contribute to many fields where pulsed electron sources are concerned; however, the aim of this thesis will focus on single-shot measurement techniques whereby a sample is imaged by a single electron pulse. In particular, I present my theoretical and experimental work in the search for the ideal photocathode material, focusing on the photoemissive characterization of these materials via their bulk and surface properties. I also present a new photoelectron gun design implemented in the experimental photocathode characterization setup at UIC that improves and enhances data collection. Finally, I conclude with my investigations into the theory and simulation of radio frequency resonant cavities as objective lenses and aberration correctors for use in pulsed electron beam physics.

History

Advisor

Schroeder, W. Andreas

Chair

Schroeder, W. Andreas

Department

Physics

Degree Grantor

University of Illinois at Chicago

Degree Level

Doctoral

Committee Member

Grein, Cristoph Hofman, David Klie, Robert Nicholls, Alan

Submitted date

August 2017

Issue date

25/08/2017

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