SKM 2023 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 8: Ultrafast Electron Dynamics at Surface and Interfaces I
O 8.5: Vortrag
Montag, 27. März 2023, 11:30–11:45, TRE Phy
Radio-frequency controlled electron pulses for time-resolved LEED — •Dennis Epp1, Benjamin Schröder1, Marcel Möller1, and Claus Ropers1,2 — 1Max-Planck-Institut für Multidisziplinäre Naturwissenschaften — 2Georg-August-Universität Göttingen
In this contribution, we demonstrate temporal compression of low-energy electron pulses using rf-fields. Specifically, we combine a millimetre-sized electron gun [1] with a rf-cavity driven by a sinusoidal wave. A phase-locked loop synthesizer controls the timing between the incident electron pulses and the sinusoidal signal. By electron energy filtering, we measured an initial energy spread of ΔE*1.5 eV for the uncompressed pulses with mean kinetic energies in the range of 50 eV to 100 eV [2]. In perspective, ULEED with sub-ps resolution will allow for the observation of the impact of electron-phonon coupling and coherent vibrational motion on the efficiencies of surface phase transitions and the resulting changes in materials functionality. [1] Vogelgesang, et al., Nature Physics 14,184-190 (2018). [2] Epp et al., in preparation