More than a decade ago: Accelerator development enabled visionary science probe-before-destroy Haidu et al. soft x-ray magnetic holography Wang, et al. PRL (2013)

Today: We need the complementarity of x-rays & electrons to access to the “Ultrafast” & “Ultrasmall” soft x-ray magnetic holography probes electrons & spins probes lattice nano-UED FePt 2nm heat sink Goal: understand & control materials processes Wang, et al. PRL (2013) Xiang, et al. SLAC report (2014) G. Bertero (WD Corp.)

X-rays or electrons? We need both! R. Henderson, Quarterly Reviews of Biophysics 28 (1995) Electrons: can be manipulated by electric & magnetic fields (microscopy) but have <10nm coherence lengths. X-rays: Fully coherent beams offer new opportunities for holographic imaging. Soft x-ray resonant inelastic cross sections are comparable to those of electrons, elastic cross sections are much lower.

The Future of Electron Scattering & Diffraction Opportunities for Ultrafast Science DOE Basic Energy Sciences Needs Workshop Report (2014) Key Breakthrough Science Opportunities and Challenges -Atomic Scale Molecular Processes -Photonic Control of Quantum Materials -Energy Transport at the Nanoscale -Mesoscale Materials and Phenomena -Evolving Interfaces, Nucleation, and Mass Transport

Nano-UED User Facility UEM User Facility Ultrafast Electron Microscopy Ultrafast Electron Diffraction The Future of Electron Scattering & Diffraction How do we get there? DOE Basic Energy Sciences Needs Workshop Report (2014)

Controlling processes on the level of electrons: Non-Born-Oppenheimer dynamics in molecules Ben-Nun and Martinez, Chem. Phys. 259, 237(2000) Absorption triggers coupled ultrafast motion of nuclei and electrons, hard to model Born-Oppenheimer violation provides fast funnels for steering energy into particular channel M. Centurion Lab U. Nebraska Aligned CF 3 I Guehr, et al. requires sub-100 fs with unfocused electron beam at high repetition rates (UED)

Opportunities for Ultrafast Materials Science requires sub-100 fs with focused electron beam at high repetition rates (nano-UED) nanoscale energy transport photonic control of quantum materials nanoscale mechanisms of phase transitions

I maging of Nanoscale Processes requires single-shot imaging (10ps - 10 nm UEM) Phase transitions: diffusionless vs. mass transport Biological processes Carbon fixation by bacterial carboxysomes

Nano-UED User Facility UEM User Facility Ultrafast Electron Microscopy Ultrafast Electron Diffraction Early Science Opportunities with UED Gas phase chemistry (sub-100fs & 100μm beam size): Experimental setup is still under development (requires isolation of gun and sample vacuum). Materials science will initially be limited by available samples: etching, exfoliation, sample growth of ~ 100μm free standing films needs to be developed) Development of laser-electron cross correlation schemes: -use laser-induced space charge -electron beam induced dynamics -photo-induced electron-lattice coupling in wide-bandgap oxides

Early Science Opportunities with UED Gas phase chemistry (sub-100fs & 100μm beam size): Experimental setup is still under development (requires isolation of gun and sample vacuum). Materials science will initially be limited by available samples: etching, exfoliation, sample growth of ~ 100μm free standing films needs to be developed) Development of laser-electron cross correlation schemes: -use laser-induced space charge -electron beam induced dynamics -photo-induced electron-lattice coupling in wide-bandgap oxides Measurement of single-shot electron diffraction from a 40nm FeRh film epitaxially grown on 10 nm MgO IBAD deposited on 100nm SiN. First results (A. Reid, R. Li, P. Musumeci)