Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 70: Structural Dynamics in Nanoscale Materials Probed by Ultrashort Electron Pulses
O 70.10: Poster
Wednesday, March 18, 2015, 18:15–21:00, Poster A
Characterization of a picosecond electron gun for diffraction experiments — •Nele L. M. Müller1, Sebastian Trippel1, Terence G. Mullins1, Karol Długołecki1, and Jochen Küpper1,2,3 — 1Center for Free-Electron Laser Science, DESY, Hamburg — 2The Hamburg Center for Ultrafast Imaging, Hamburg — 3Department of Physics, University of Hamburg
The aim of the presented work is to investigate the structure and dynamics of molecules in the gas-phase by electron diffraction experiments. The contribution presents our newly set-up electron gun that will be combined with an existing controlled-molecules apparatus [1]. The developed DC electron gun can produce up to 10 million electrons per pulse and uses an electro-static lens for focusing. The expected pulse durations are tens of picoseconds. The focusing electrodes are arranged in a configuration similar to a Velocity Map Imaging spectrometer. Besides focusing this can be used to measure the spatial and velocity distribution of the electron pulse when emitting from the cathode. In combination with electron trajectory simulations this allows for further characterization of the electron beam, as for example the determination of pulse duration and coherence length. Electron diffraction data from solid state and gaseous samples will be presented.
[1]Trippel et al., Mol. Phys. 111, 1738-1743 (2013)