FEL2026 - 42nd International Free Electron Laser Conference

Greater than 1000-fold Gain in a Free-Electron Laser Driven by a Laser-Plasma Accelerator with High Reliability

FRX01

28 Aug 2026, 08:30

25m

Invited Oral Presentation Session 9: Novel Accelerator and FEL Concepts Novel Accelerator and FEL Concepts (Invited)

Speaker

Samuel Barber (Lawrence Berkeley National Laboratory)

Description

Compact free-electron lasers (FELs) based on plasma-based accelerators have been envisioned for many years. While recent milestone experiments have demonstrated their feasibility, further progress is required to establish laser-plasma-accelerator-driven FELs as reliable light sources. Demonstrating both full FEL saturation and operational reliability comparable to conventional FEL facilities is essential. Here, we report progress on both fronts. FEL gain exceeding 1000 at a wavelength of 420 nm in the self-amplified spontaneous emission regime has been measured. Lower and upper bounds for the characteristic exponential gain length were determined to be 16.7–22.5 cm. In addition, the reliability of the laser-plasma-accelerator-driven FEL, defined here as the percentage of shots exhibiting FEL gain, reached an unprecedented level exceeding 90% over the course of an hour while operating at a 1 Hz repetition rate.

Funding Agency

U.S. Department of Energy (DOE), Office of Science, BES and HEP, Contract No. DE-AC02-05CH1123.
CRADA with Tau Systems
Gordon and Betty Moore Foundation