A new facility at the Department of Energy (DOE)’s SLAC National Accelerator Laboratory (Menlo Park, CA) will combine a petawatt laser with an x-ray free-electron laser (XFEL) that can probe Earth’s extreme conditions in an unprecedented way. Coupled to the lab’s Linac Coherent Light Source (LCLS), the Matter in Extreme Conditions Upgrade (MEC-U) promises to dramatically improve our understanding of the conditions needed to produce fusion energy and to replicate a wide range of astrophysical phenomena here on Earth.
The project got approval from the DoE Office of Science (SC) on October 4, 2021, to move from its conceptual design phase to preliminary design and execution, having passed what is known as Critical Decision 1.
SLAC will work in partnership with the Lawrence Livermore National Laboratory (LLNL; Livermore, CA) and the University of Rochester’s Laboratory for Laser Energetics (LLE; Rochester, NY) to design and construct the facility in a new underground cavern. There, two state-of-the-art laser systems—a high-power petawatt laser and a high-energy kilojoule laser—will feed into two new experimental areas dedicated to the study of hot dense plasmas, astrophysics, and planetary science.
This project builds on the success achieved at the existing Matter in Extreme Conditions (MEC) instrument at LCLS. Funded by DOE SC’s Fusion Energy Sciences program (FES), MEC uses short-pulse lasers coupled to x-ray laser pulses from LCLS to probe the characteristics of matter with unprecedented precision. These experiments have delivered a wealth of outstanding science and attracted worldwide media attention, with examples such as the study of “diamond rain” thought to exist on Neptune, to investigating the signatures of asteroid impacts on the Earth, to studying potential failure mechanisms of satellites due to solar flares.
The existing MEC instrument is, however, limited in the regimes it can access. It has only modest laser capabilities, which don’t allow it to reach the conditions of highest interest to researchers. The community called for investment into a petawatt laser that can produce unprecedented light pressures and generate plasmas at the even higher temperatures found in cosmic collisions, the cores of stars and planets, and fusion devices, giving scientists access to more extreme forms of matter needed to address the most important scientific challenges identified by the broad community of scientific users.
MEC-U will also take advantage of the LCLS-II upgrade to the LCLS facility, which will provide x-ray laser beams of unsurpassed brilliance for probing those plasmas, doubling the x-ray energy that has been attainable to date.
Access to the facility will be open to researchers from across the country and around the world, facilitated in part by LaserNetUS, a research network that is boosting access to high-intensity laser facilities at labs and universities across the country. This will allow more MEC users in a broader range of fields to use the facility, while also helping train new staff and develop new techniques.