Ultracold and ultrafast electron beams for diffraction and microscopy

At Eindhoven University of Technology we are developing new methods for generating beams for ultrafast electron diffraction and microscopy. By femtosecond photoionization of a laser-cooled gas we produce highly charged, highly coherent electron bunches, which ultimately should enable single-shot electron diffraction of macromolecules. Using a simple graphite sample we recently generated the first diffraction patterns with the ultracold electron source, which provided direct evidence that the source has the required coherence. We are currently characterizing the longitudinal phase space of the ultracold electron bunches and we are preparing crystalline samples of the 2D membrane protein hydrophobin. Progress will be reported. By implementing an ultrafast, RF-cavity-based beam blanker in a FEI Tecnai TEM we will realize ‘stroboscopic’ ultrafast electron microscopy with substantially improved performance in terms of spatial resolution, temporal resolution, and data acquisition time. A specially designed compact and energy efficient RF cavity is currently being prepared for installation in the TEM. Progress will be reported.