Signal LLNL and Pacific Fusion achieve 3,000-shot milestone with Sirius pulsed-power prototype

Summary

SIRIUS, the four-stage impedance-matched Marx generator prototype at Lawrence Livermore National Laboratory, passed 3,000 shots, a milestone reportedly achieved on 15 May 2026 and announced on 20 July 2026. The device delivers 60 GW to a resistive load per 100-nanosecond pulse at 95% energy efficiency, and evaluators place this at the transition from DOE technology readiness level 4 toward level 5, defined as system demonstration in a laboratory test environment. The 3,000-shot threshold is tied to commercial accelerator component lifetime requirements of up to 100 shots per year over a 30-year service life. The impedance-matched Marx generator technology was invented by LLNL researcher Bill Stygar and Pacific Fusion cofounder and CTO Keith LeChien. The work was conducted under a CRADA with Pacific Fusion, which is scaling the technology into a module built roughly 40 times larger in parallel for its modular pulser platform, and which separately announced in June a prototype validated at a peak of 440 GW and 1.1 MV over 80 nanoseconds, about eleven times more powerful than SIRIUS. Cumulative private funding for Pacific Fusion has passed $1 billion, with a net facility gain targeted for 2030.