Pacific Fusion and LLNL's Sirius Pulsed-Power Prototype Surpasses 3,000 Shots

Pacific Fusion announced on July 16, 2026 that Sirius, a pulsed-power prototype designed and built at Lawrence Livermore National Laboratory on the impedance-matched Marx generator (IMG) architecture co-invented by Pacific Fusion CTO Keith LeChien during his time at the lab, surpassed 3,000 shots. Each pulse of the four-stage prototype delivered 60 gigawatts to a resistive load in a 100-nanosecond burst at 95% energy efficiency, demonstrating the reliability and repeatability needed to scale the architecture for high-gain inertial fusion energy. Pacific Fusion has already built a prototype roughly 11 times larger using the same core technology, delivering the highest peak power ever demonstrated by a single-step pulsed-power driver (440 GW, announced June 2, 2026). The milestone illustrates how national-lab breakthroughs are moving rapidly into commercial fusion infrastructure.