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HK: Fachverband Physik der Hadronen und Kerne
HK 53: Poster - Instrumentation II
HK 53.10: Poster
Wednesday, March 6, 2013, 16:45–19:00, HSZ 3.OG
Investigation of the work function fluctuations of electrodes for high precision low energy experiments — •Marcus Beck1, Werner Heil1, Ernst-Wilhelm Otten1, Alexander Wunderle1, Martin Babutzka2, Kerstin Schönung2, Klaus Schlösser2, Matt Bahr3, and Benjamin Monreal3 — 1Institut für Physik, Johannes Gutenberg Universität Mainz — 2Institut für Experimentelle Kernphysik KIT, Karlsruhe — 3Department of Physics, University of California, Santa Barbara, USA
High precision experiments at low energies are used in several areas of fundamental physics. Examples are, a.o., high precision beta decay experiments and experiments using Penning traps for mass measurements or for g-factor measurements. The knowledge of the potentials and potential differences inside these experiments is crucial to achieve the desired sensitivities. However, the potentials are modified by the work function of the electrodes, which can show fluctuations of of several hundred meV, both spatially and temporally. For the low energy precision experiments aSPECT and KATRIN we have commissioned and studied a scanning Kelvin probe system to investigate the work function fluctuations of gold surfaces on different substrates. Since the Kelvin probe is a relative method, also photoelectron spectroscopy was performed additionally to obtain information on the absolute work functions. The temporal stability of the work functions of the surfaces was also tested, as well as the influence of standard cleaning procedures for ultra-high vacuum applications and bake-out. This poster will present the results of these measurements.