Regensburg 2016 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 12: Postersession DS
DS 12.31: Poster
Montag, 7. März 2016, 17:00–19:00, Poster A
Thermal Electron Emission from LaB6 und BaO in a Thermionic Set-Up — •Michael Hohage1, Michael Schneiderbauer2, Mariella Denk1, Anna Steiner1, Markus Gusenbauer1, and Peter Zeppenfeld1 — 1Institut für Experimentalphysik, Abt. für Atom- und Oberflächenphysik, Johannes Kepler Universität Linz, Altenbergerstraße 69, 4040 Linz, Austria — 2te+, Quellenweg 33, 4203 Altenberg, Austria
Thermionic emission is a promising approach to convert heat into electric energy at temperatures reached by burning wood or fossil fuels. We have studied the electron emission from the materials LaB6 and BaO at temperatures up to 1550 K. The cathode and anode surfaces are coplanar for the purpose of a systematic study of the electron emission yield as a function of distance. The electrode temperatures are measured by thermocouples and an infrared pyrometer.
We show the dependence of the thermionic emission current on temperature, distance and on the activation procedure of the BaO electrode. A simple model of the magnitude of the space charge and its influence on thermal electron emission will be introduced. Concepts to lower the space charge and its effect on the thermal emission will be presented and tested against simulations and experiments. In particular, the role of the geometry and macrostructure of the electrodes as well as the influence of external electric and magnetic fields will be discussed.