Print Email Facebook Twitter Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker Title Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker Author Weppelman, I.G.C. (TU Delft ImPhys/Charged Particle Optics; TU Delft ImPhys/Imaging Physics) Moerland, R.J. (TU Delft ImPhys/Quantitative Imaging; TU Delft ImPhys/Imaging Physics) Zhang, L (TU Delft ImPhys/Imaging Physics; Beihang University) Kieft, E. (TU Delft Architecture and the Built Environment) Kruit, P. (TU Delft ImPhys/Imaging Physics; TU Delft ImPhys/Charged Particle Optics) Hoogenboom, J.P. (TU Delft ImPhys/Charged Particle Optics; TU Delft ImPhys/Imaging Physics) Faculty Architecture and the Built Environment Department ImPhys/Imaging Physics Date 2019 Abstract Crucial for the field of ultrafast electron microscopy is the creation of sub-picosecond, high brightness electron pulses. The use of a blanker to chop the beam that originates from a high brightness Schottky source may provide an attractive alternative to direct pulsed laser illumination of the source. We have recently presented the concept of a laser-triggered ultrafast beam blanker and argued that generation of 100 fs pulses could be possible [Weppelman et al., Ultramicroscopy 184, 8-17 (2017)]. However, a detailed analysis of the influence of a deflection field changing sign on sub-picoseconds time scale on the quality of the resulting electron pulses has so far been lacking. Here, we present such an analysis using time-dependent, three-dimensional numerical simulations to evaluate the time-evolution of deflection fields in and around a micrometers-scale deflector connected to a photo-conductive switch. Further particle tracing through the time-dependent fields allows us to evaluate beam quality parameters such as energy spread and temporal broadening. We show that with a shielded, "tunnel-type" design of the beam blanker limiting the spatial extent of fringe fields outside the blanker, the blanker-induced energy spread can be limited to 0.5 eV. Moreover, our results confirm that it could be possible to bring laser-triggered 100 fs focused electron pulses on the sample using a miniaturized ultrafast beam blanker. This would enable us to resolve ultrafast dynamics using focused electron pulses in an SEM or STEM. Subject OA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:8cc715a1-18e6-46f8-96f4-0c6ecafe7aae DOI https://doi.org/10.1063/1.5089517 Source Structural Dynamics, 6 (2) Part of collection Institutional Repository Document type journal article Rights © 2019 I.G.C. Weppelman, R.J. Moerland, L Zhang, E. Kieft, P. Kruit, J.P. Hoogenboom Files PDF 1.5089517.pdf 3.84 MB Close viewer /islandora/object/uuid:8cc715a1-18e6-46f8-96f4-0c6ecafe7aae/datastream/OBJ/view