Toward Å-fs-meV Resolution in Electron Microscopy: Systematic Simulation of the Temporal Spread of Single-Electron Packets

Wyatt A. Curtis, David Flannigan

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Though efforts to improve the temporal resolution of transmission electron microscopes (TEMs) have waxed and waned for decades, with relatively recent advances routinely reaching sub-picosecond scales, fundamental and practical challenges have hindered the advance of combined Å-fs-meV resolutions, particularly for core-loss spectroscopy and real-space imaging. This is due in no small part to the complexity of the approach required to access timescales upon which electrons, atoms, molecules, and materials first begin to respond and transform-attoseconds to picoseconds. Here we present part of a larger effort devoted to systematically mapping the instrument parameter space of a TEM modified to reach ultrafast timescales. With General Particle Tracer, we studied the statistical temporal distributions of single-electron packets as a function of various fs pulsed-laser parameters and electron-gun configurations and fields for the exact architecture and dimensions of a Thermo Fisher Tecnai Femto ultrafast electron microscope. We focused on easily-adjustable parameters, such as laser pulse duration, laser spot size, photon energy, Wehnelt aperture diameter, and photocathode size. In addition to establishing trends and dispersion behaviors, we identify regimes within which packet duration can be 100s of fs and approach the 300 fs laser limit employed here. Overall, the results provide a detailed picture of the temporal behavior of single-electron packets in the Tecnai Femto gun region, forming the initial contribution of a larger effort.

Original languageEnglish (US)
Pages (from-to)23544-23553
Number of pages10
JournalPhysical Chemistry Chemical Physics
Volume23
Issue number41
DOIs
StatePublished - Nov 7 2021

Bibliographical note

Funding Information:
This material is based on work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0018204. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1839286. This work was supported partially by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401. Acknowledgement is made to the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research under Award No. 60584-ND10. We thank Dr Erik Kieft of Thermo Fisher Scientific for assistance with modeling the FEI Tecnai Femto architecture and for ensuring accurate electrostatic field maps were generated.

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MRSEC Support

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PubMed: MeSH publication types

  • Journal Article

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