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Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker
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 sou...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Crystallographic Association
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6486391/ https://www.ncbi.nlm.nih.gov/pubmed/31065571 http://dx.doi.org/10.1063/1.5089517 |
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author | Weppelman, I. G. C. Moerland, R. J. Zhang, L. Kieft, E. Kruit, P. Hoogenboom, J. P. |
author_facet | Weppelman, I. G. C. Moerland, R. J. Zhang, L. Kieft, E. Kruit, P. Hoogenboom, J. P. |
author_sort | Weppelman, I. G. C. |
collection | PubMed |
description | 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. |
format | Online Article Text |
id | pubmed-6486391 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | American Crystallographic Association |
record_format | MEDLINE/PubMed |
spelling | pubmed-64863912019-05-07 Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker Weppelman, I. G. C. Moerland, R. J. Zhang, L. Kieft, E. Kruit, P. Hoogenboom, J. P. Struct Dyn ARTICLES 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. American Crystallographic Association 2019-04-26 /pmc/articles/PMC6486391/ /pubmed/31065571 http://dx.doi.org/10.1063/1.5089517 Text en © 2019 Author(s). 2329-7778/2019/6(2)/024102/11 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | ARTICLES Weppelman, I. G. C. Moerland, R. J. Zhang, L. Kieft, E. Kruit, P. Hoogenboom, J. P. 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 |
title_full | Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker |
title_fullStr | Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker |
title_full_unstemmed | Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker |
title_short | Pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker |
title_sort | pulse length, energy spread, and temporal evolution of electron pulses generated with an ultrafast beam blanker |
topic | ARTICLES |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6486391/ https://www.ncbi.nlm.nih.gov/pubmed/31065571 http://dx.doi.org/10.1063/1.5089517 |
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