Development And Characterization Of An Electron Gun For Ultrafast Electron Microscopy

Development and Characterization of an Electron Gun for Ultrafast Electron Microscopy

Ultrafast electron microscopy is an emerging field of research offering the potential to investigate structural processes on a femtosecond time-scale with nanometer resolution. In order to further advance ultrafast electron microscopes, an improvement of the electron gun is necessary with respect to spatial and temporal beam properties as well as the electron yield. In this thesis, photoemission characteristics of laser-driven nanotip cathodes incorporated into a Schottky-type emitter assembly are experimentally and theoretically investigated. Specifically, electron trajectories, emission p...

Development of an Ultrafast Low-Energy Electron Diffraction Setup

This book presents an Ultrafast Low-Energy Electron Diffraction (ULEED) system that reveals ultrafast structural changes on the atomic scale. The achievable temporal resolution in the low-energy regime is improved by several orders of magnitude and has enabled the melting of a highly-sensitive, molecularly thin layer of a polymer crystal to be resolved for the first time. This new experimental approach permits time-resolved structural investigations of systems that were previously partially or totally inaccessible, including surfaces, interfaces and atomically thin films. It will be of fundamental importance for understanding the properties of nanomaterials so as to tailor their properties.

Scientific and Technical Aerospace Reports