SLAC Megaelectronvolt Ultrasfast Electron Diffraction Instrument: MeV-UED

Short Description

The MeV-UED instrument, part of the LCLS User Facility, is a powerful "electron camera" for the study of time-resolved, ultrafast atomic & molecular dynamics in chemical and solid-state systems. Taking advantage of the LCLS-II upgrade period, MeV-UED has been established based on the successful research program at SLAC using MeV electron diffraction. This instrument has demonstrated the following properties:  high spatial resolution (< 0.5 Å), large momentum-transfer range (0.5 to 12 Å-1), high elastic scattering cross sections, high temporal resolution (< 150 fs FWHM), with the additional benefits of relatively large penetration depths (> 100 nm) and negligible sample damage. See current specifications.

Since 2014, the SLAC UED instrument has been developing robust methods in the pursuit of time-resolved measurements to control and understand molecular structural dynamics and the coupling of electronic and nuclear motions in a variety of material and chemical systems. Driven by a broad array of collaborating teams at SLAC and around the world, the UED instrument has produced an impressive array of high impact publications. Examples range from imaging the motions of monolayer MoS2, to atomic level movies of light-induced structural distortion in perovskites solar cells, along with molecular movies of chemical bond breaking, ring-opening, and nuclear wavepacket at conical intersections in isolated molecules. MeV-UED has also successfully explored various diffuse scattering and warm dense matter physics applications.

Call for Proposals

Leveraging the prior scientific successes along with recent system-level improvements in stability, SLAC is pleased to announce MeV-UED’s first external user experimental time ("Run 1") in mid 2019, taking full advantage of the LCLS-II upgrade/downtime period.

In Run 1, MeV-UED instrument will offer two experimental configurations (see Endstations and Specifications): one solid state/materials and one single-shot/warm dense matter setup. The intent of these configurations is to maximize scientific beamtime by minimizing insturement downtime for switching, setting up, and testing disparate configurations.

Proposals will be considered on a case by case basis if the requested experimental parameters fall outside of the defined capabilities. For more information, please contact the MeV-UED staff.