Regensburg 2016 – scientific programme
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O: Fachverband Oberflächenphysik
O 47: Electronic Structure of Surfaces: Spectroscopy, Surface States
O 47.5: Poster
Tuesday, March 8, 2016, 18:15–20:30, Poster E
Towards ToF Momentum Microscopy With CW Sources Using an Ultrafast Chopper Scheme — •Anna Zaporozhchenko1,2, Olena Fedchenko1, Katerina Medjanik3,1, Sergej Chernov1, Andreas Oelsner4, Hans-Joachim Elmers1,2, and Gerd Schönhense1,2 — 1Institut für Physik, JOGU, 55099 Mainz, Germany — 2Graduate School of Excellence MAINZ, 55128 Mainz, Germany — 3Lund University, MAX IV Laboratory, 22100 Lund, Sweden — 4Surface Concept GmbH, 55124 Mainz, Germany
The use of time-of-flight techniques for high-resolution spectroscopy and momentum microscopy requires a defined time structure of the photon beam. The time resolution of 3D (x,y,t)-resolving detectors, e.g. the delay-line detector, is typically 150 ps [1]. Thus a period of the exciting photon pulses of 200 ns (pulse rate of 5 MHz) yields more than 1000 time slices, sufficient for high-resolution spectroscopy. We developed an ultrafast electron-optical deflector system capable of chopping the desired pulse repetition rate out of a faster pulse train or even out of a continuous-wave signal. A first experiment with a laboratory He source was performed. In the first prototype pulse profiles of 2 ns width have been achieved. One goal is to chop lower pulse rates from the 100 or 500 MHz multibunch signal of storage rings. The current status of this development will be shown. Funded by BMBF (05K13UM1)