Coherent femtosecond low-energy single-electron pulses for time-resolved diffraction and imaging: A numerical study

Journal Article · Sat Dec 01 00:00:00 EST 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4768204· OSTI ID:22089598

Paarmann, A.; Mueller, M.; Ernstorfer, R. ^[1]; Gulde, M.; Schaefer, S.; Schweda, S.; Maiti, M.; Ropers, C. ^[2]; Xu, C. ^[1]; Hohage, T. ^[3]; Schenk, F. ^[2]

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1. Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany)
2. Courant Research Center Physics and Material Physics Institute, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)
3. Institute of Numerical and Applied Mathematics, University of Goettingen, Lotzestr. 16-18, 37083 Goettingen (Germany)

We numerically investigate the properties of coherent femtosecond single electron wave packets photoemitted from nanotips in view of their application in ultrafast electron diffraction and non-destructive imaging with low-energy electrons. For two different geometries, we analyze the temporal and spatial broadening during propagation from the needle emitter to an anode, identifying the experimental parameters and challenges for realizing femtosecond time resolution. The simple tip-anode geometry is most versatile and allows for electron pulses of several ten of femtosecond duration using a very compact experimental design, however, providing very limited control over the electron beam collimation. A more sophisticated geometry comprising a suppressor-extractor electrostatic unit and a lens, similar to typical field emission electron microscope optics, is also investigated, allowing full control over the beam parameters. Using such a design, we find {approx}230 fs pulses feasible in a focused electron beam. The main limitation to achieve sub-hundred femtosecond time resolution is the typical size of such a device, and we suggest the implementation of more compact electron optics for optimal performance.

• OSTI ID: 22089598
• Journal Information: Journal of Applied Physics, Vol. 112, Issue 11; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COHERENT RADIATION
COLLIMATORS
ELECTRON BEAMS
ELECTRON DIFFRACTION
ELECTRON MICROSCOPES
ELECTRON MICROSCOPY
EQUIPMENT
FIELD EMISSION
LENSES
NANOSTRUCTURES
NUMERICAL ANALYSIS
PHOTOEMISSION
SPECTROSCOPY
TIME RESOLUTION
WAVE PACKETS