Session H41: Irving Langmuir Prize Session: Ultrafast Dynamics
8:00 AM–10:36 AM, Tuesday, March 22, 2011
Room: A115/117
Chair: Oliver Gessner, Lawrence Berkeley National Laboratory
Abstract ID: BAPS.2011.MAR.H41.4
Abstract: H41.00004 : Quantitative imaging of ultrashort photoelectron pulse dynamics
9:24 AM–9:36 AM
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Abstract 
Authors:
Zhensheng Tao
(Michigan State University)
He Zhang
(Michigan State University)
Phillip Duxbury
(Michigan State University)
Martin Berz
(Michigan State University)
Chong-yu Ruan
(Michigan State University)
Understanding and mitigating the space charge effects is a pressing issue in the development of ultrafast electron diffraction and imaging. Using a novel ultrafast projection imaging technique, quantitative imaging of transient space charge effects in the generation of high density ultrashort electron pulses is performed, which offers a means to directly compare with multi-electron calculations. We establish that the pulse width exhibits a fractional power-law scaling with the sheet density of the emitted electron pulses. By comparing to multi-electron simulations, the initial longitudinal phase space of the photoelectrons is extracted, demonstrating a strong dependence of the initial momentum spread on the sheet density. Multielectron effects are treated using a simple extension of single electron photoemission theory yielding qualitatively correct estimates of the quantum efficiency.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.MAR.H41.4