A beam of electrons crossed just a few millimeters of plasma, then helped trigger an effect that usually belongs to massive research sites. In this case, the light produced fell in the extreme ultraviolet range, at wavelengths from 27 to 50 nanometers. The result points toward a future where some accelerator technology may shrink from building-sized systems to something much smaller. “Our work has made several substantial improvements over previous techniques, allowing us to achieve free-electron laser amplification at extreme ultraviolet wavelengths,” lead author Zhan Jin said. Proof-of-concept experimental setup used to generate an extreme ultraviolet (XUV) free-electron laser (FEL) driven by a laser wakefield acceleration (LWFA) electron beam. (CREDIT: University of Osaka) Taming a difficult accelerator Traditional particle accelerators, including radiofrequency linear accelerators and synchrotrons, have pushed physics forward for decades. They are also expensive, physically large, and limited in how strongly they can accelerate particles over a given distance. Laser wakefield acceleration offers a very different path. Instead of relying on long conventional structures, it sends a powerful laser through plasma, where it …