Building the next generation ultrafast electron microscope

Program Description:
I will discuss a new concept of ultrafast electron microscopy to boost its signal dynamical range while maintaining femtosecond (fs) and sub-eV resolution by directly controlling its space-charge dynamics.  A key ingredient is the adaptive RF optics for phase space manipulation, resulting in high combined spatial, spectral, and temporal resolutions at the space-charge limits.  Utilizing the thus generated fs coherent electron beams, we (re)investigated the photo-induced meta-stable and hidden states in electronic crystals. We uncovered a surprising generality of self-organizing behavior emerging at nonequilibrium and the otherwise unresolved phonon dynamics in diffusive scattering.  These results demonstrate the utilities of the adaptive optics in a next-generation electron microscope, which may be extended to the MeV scale where more efficient control of space-charge dynamics is possible.