Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 36: Poster Session II (Organic films and electronics, photoorganics; Nanostructures; Plasmonics and nanooptics, Surface chemical reactions and heterogeneous catalysis, Surface dynamics )

O 36.28: Poster

Dienstag, 12. März 2013, 18:15–21:45, Poster B2

Numerical investigation of laser-triggered nanometer-sized electron sources for ultrafast low-energy electron diffraction (ULEED) and ultrafast transmission electron microscopy (UTEM) — Stefanie Strauch, Simon Schweda, Max Gulde, Reiner Bormann, •Sascha Schäfer, and Claus Ropers — Materials Physics Institute and Courant Research Centre, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen

Sharp metallic tips excited by ultrashort laser pulses serve as promising electron sources for both UTEM and ULEED, due to their nanometer-sized emission area and large field enhancement at the tip apex. As part of the Göttingen UTEM initiative, we study the beam characteristics of pulsed Schottky field emitters within electron microscope geometries. In order to achieve optimal temporal and spatial pulse properties, it is crucial to understand the propagation of the photoemitted electron pulse in the beam-shaping electron optics for both high and low electron energy applications. We numerically investigate the electron optical design to improve the temporal pulse width, as well as the effective source size and beam emittance, and compare our findings with experimental results.