Title: Segmented Terahertz Electron Accelerator and Manipulator (STEAM),
Abstract: Acceleration and manipulation of ultrashort electron bunches are the basis
behind electron and X-ray devices used for ultrafast, atomic-scale imaging and
spectroscopy. Using laser-generated THz drivers enables intrinsic
synchronization as well as dramatic gains in field strengths, field gradients
and component compactness, leading to shorter electron bunches, higher
spatio-temporal resolution and smaller infrastructures. We present a segmented
THz electron accelerator and manipulator (STEAM) with extended interaction
lengths capable of performing multiple high-field operations on the energy and
phase-space of ultrashort bunches with moderate charge. With this single
device, powered by few-microjoule, single-cycle, 0.3 THz pulses, we demonstrate
record THz-device acceleration of >30 keV, streaking with <10 fs resolution,
focusing with >2 kT/m strengths, compression to ~100 fs as well as real-time
switching between these modes of operation. The STEAM device demonstrates the
feasibility of future THz-based compact electron guns, accelerators, ultrafast
electron diffractometers and Free-Electron Lasers with transformative impact.