Time-of-flight photoelectron momentum microscopy with 80-500 MHz photon sources electron-optical pulse picker or bandpass pre-filter

Time-of-flight photoelectron momentum microscopy with 80-500 MHz photon sources : electron-optical pulse picker or bandpass pre-filter

open access.

Bibliographische Detailangaben
Veröffentlicht in:Journal of synchrotron radiation. - 1994. - 28(2021), Pt 6 vom: 01. Nov., Seite 1891-1908
1. Verfasser: Schönhense, G (VerfasserIn)
Weitere Verfasser: Medjanik, K, Fedchenko, O, Zymaková, A, Chernov, S, Kutnyakhov, D, Vasilyev, D, Babenkov, S, Elmers, H J, Baumgärtel, P, Goslawski, P, Öhrwall, G, Grunske, T, Kauerhof, T, von Volkmann, K, Kallmayer, M, Ellguth, M, Oelsner, A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2021
Zugriff auf das übergeordnete Werk:Journal of synchrotron radiation
Schlagworte:Journal Article ARPES momentum microscopy photoelectron diffraction pulse picking time-of-flight spectroscopy
Beschreibung
Zusammenfassung:open access.
The small time gaps of synchrotron radiation in conventional multi-bunch mode (100-500 MHz) or laser-based sources with high pulse rate (∼80 MHz) are prohibitive for time-of-flight (ToF) based photoelectron spectroscopy. Detectors with time resolution in the 100 ps range yield only 20-100 resolved time slices within the small time gap. Here we present two techniques of implementing efficient ToF recording at sources with high repetition rate. A fast electron-optical beam blanking unit with GHz bandwidth, integrated in a photoelectron momentum microscope, allows electron-optical `pulse-picking' with any desired repetition period. Aberration-free momentum distributions have been recorded at reduced pulse periods of 5 MHz (at MAX II) and 1.25 MHz (at BESSY II). The approach is compared with two alternative solutions: a bandpass pre-filter (here a hemispherical analyzer) or a parasitic four-bunch island-orbit pulse train, coexisting with the multi-bunch pattern on the main orbit. Chopping in the time domain or bandpass pre-selection in the energy domain can both enable efficient ToF spectroscopy and photoelectron momentum microscopy at 100-500 MHz synchrotrons, highly repetitive lasers or cavity-enhanced high-harmonic sources. The high photon flux of a UV-laser (80 MHz, <1 meV bandwidth) facilitates momentum microscopy with an energy resolution of 4.2 meV and an analyzed region-of-interest (ROI) down to <800 nm. In this novel approach to `sub-µm-ARPES' the ROI is defined by a small field aperture in an intermediate Gaussian image, regardless of the size of the photon spot
Beschreibung:Date Revised 05.10.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1600-5775
DOI:10.1107/S1600577521010511