A pulsed electron gun for ultrafast electron diffraction at surfaces
- Department of Physics and Centre for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg (Germany)
The construction of a pulsed electron gun for ultrafast reflection high-energy electron diffraction experiments at surfaces is reported. Special emphasis is placed on the characterization of the electron source: a photocathode, consisting of a 10 nm thin Au film deposited onto a sapphire substrate. Electron pulses are generated by the illumination of the film with ultraviolet laser pulses of femtosecond duration. The photoelectrons are emitted homogeneously across the photocathode with an energy distribution of 0.1 eV width. After leaving the Au film, the electrons are accelerated to kinetic energies of up to 15 keV. Focusing is accomplished by an electrostatic lens. The temporal resolution of the experiment is determined by the probing time of the electrons traveling across the surface which is about 30 ps. However, the duration of the electron pulses can be reduced to less than 6 ps.
- OSTI ID:
- 20953242
- Journal Information:
- Review of Scientific Instruments, Vol. 78, Issue 1; Other Information: DOI: 10.1063/1.2431088; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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