title: Transition radiation in EELS and cathodoluminescence.
abstract: The excitation probability of transition radiation is measured for varying beam energies in a transmission electron microscope once using optical spectrometry of the emitted light and second using electron energy loss spectrometry. In both cases similar results are found being in good agreement with theory. The knowledge about this probability enables us to judge whether or not transition radiation has to be considered in EELS and CL data interpretation. Additionally it is shown that the emission of transition radiation happens at the sample surfaces only, when the electron passes the vacuum/sample interface and thus feeling the change of its dielectric environment. We demonstrate that in the case of aluminum the influence of transition radiation on the low loss EELS spectrum is only minor and conclude that it might be negligible for many other materials.
authors.affiliation: University Service Center for Transmission Electron Microscopy, Technische Universität Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria. Electronic address: stoeger@ustem.tuwien.ac.at.
authors.forename: Michael
authors.initials: M
authors.lastname: Stöger-Pollach
authors.affiliation: University Service Center for Transmission Electron Microscopy, Technische Universität Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Kachtík
authors.affiliation: University Service Center for Transmission Electron Microscopy, Technische Universität Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Miesenberger
authors.affiliation: University Service Center for Transmission Electron Microscopy, Technische Universität Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Retzl
keywords: Cathodoluminescence; EELS; Transition radiation