MeV-UED (Megaelectronvolt Ultrafast Electron Diffraction)
Run 7 Call for Proposals is open!
For period October 2026 to August 2027
Submission Deadline: 17 April 2026 at 4pm (PDT)
We're pleased to announce the proposal call for MeV-UED’s seventh external user experimental run, scheduled to begin in October 2026. In Run 7, LCLS MeV-UED will offer two specialized chambers dedicated to solid-state experiments. The first chamber, the Cryo and Quantum Materials Chamber, is optimized to facilitate experiments conducted at or below room temperature. The second chamber, the Single-Shot and High Temperature Chamber, offers a range of configurations to accommodate versatile experimental requirements including single-shot experiments, high-temperature experiments, and experiments involving electrical excitation or biasing. Both chambers offer a broad range of optical pumps at their interaction points.
The LCLS MeV-UED Instrument
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. MeV-UED operations have been established based on the successful MeV electron diffraction research program at SLAC. 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. See Intro to MeV-UED video.
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 MeV-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.
Proposals Calls
The MeV-UED instrument, part of the Linac Coherent Light Source (LCLS) user facility at SLAC National Accelerator Laboratory encourages scientists from diverse fields to propose experiments utilizing the MeV-UED's unique capabilities. Access to MeV-UED is open to the international community. There is no cost to submit proposals or conduct experiments at MeV-UED. However, users are responsible for their own travel expenses and (in rare cases) for any extraordinary consumables required by the experiment. Please refer to the proposal review process prior to writing your proposal.
MeV-UED Data Analysis
MeV-UED staff scientist Yusong Liu led a data analysis tutorial workshop on October 23rd 2023 aimed at gas-phase photochemistry. Link to the workshop recording and materials. Data analysis instructions for solid-state materials science are also available.
External Resource: A complete beamtime online analysis package is available on GitHub at https://github.com/lheald2/gued, maintained by MeV-UED user Lauren Heald. To access the most up-to-date version, clone the repository to your S3DF account and refer to the accompanying analysis guide for usage instructions. Link to the analysis instruction materials.
LCLS MeV-UED Acknowledgement: Proposal teams must inform and acknowledge MeV-UED and the DOE Office of Science in presentations and publications using this template:
"MeV-UED is operated as part of the Linac Coherent Light Source at the SLAC National Accelerator Laboratory, supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515"
