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O: Fachverband Oberflächenphysik
O 5: Ultrafast Electron Dynamics at Surfaces and Interfaces I
O 5.6: Vortrag
Montag, 18. März 2024, 11:45–12:00, MA 041
GHz manipulation of low-energy electron pulses — •Dennis Epp1,2, Benjamin Schröder1,2, Marcel Möller1,2, and Claus Ropers1,2 — 1Department of Ultrafast Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany — 24th Physical Institute - Solids and Nanostructures, University of Göttingen, 37077 Göttingen, Germany
Electron pulses are a powerful probe in time-resolved diffraction and microscopy. One of the main challenges in such experiments is the dispersion-induced pulse broadening, both due to Coulomb interactions and the initial photoelectron energy distribution [1]. One technique to overcome this challenge is radio-frequency (RF) pulse compression, which is routinely used to control high-energy electron pulses [2]. However, corresponding schemes have not been developed for energies below a few kilo-electronvolts.
In this contribution, we demonstrate longitudinal phase-space manipulation of low-energy electron pulses using RF fields. Specifically, we combine a millimetre-sized photoelectron gun [3] with a synchronized compression cavity driven at a frequency of 2.5GHz. The change in pulse duration induced by the cavity is measured by the deflection of transient space-charge cloud at a metal grid, resulting in a two- to four-fold compression of 80-,100- and 120-eV electron pulses [4].
[1] Dwyer, et al., Phil. Trans. R. Soc. 364,741-778 (2006). [2] Kassier, et al., Applied Physics B 109, 249-257 (2012). [3] Vogelgesang, et al., Nature Physics 14,184-190 (2018). [4] Epp et al., under review.
Keywords: Electron pulse compression; Low-energy electron diffraction; Method development