Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

TLDR

Ultrafast electron probes, complementary to x‑ray free‑electron lasers, enable the study of structural dynamics in materials, chemicals, and biology with femtosecond pulses and atomic‑scale resolution. SLAC launched the Ultrafast Electron Diffraction and microscopy Initiative to develop next‑generation ultrafast electron scattering instruments. The first stage of the Initiative built and commissioned a mega‑electron‑volt UED system for ultrafast science experiments and instrumentation development. The MeV UED system achieves a 120‑Hz repetition rate, high reciprocal‑space resolution, excellent temporal resolution, and stable operation.

Abstract

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.