Observations and properties of the first laboratory fusion experiment to exceed a target gain of unity.

Abstract

An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05MJ of laser light at a wavelength of 351nm and produced 3.1±0.16MJ of total fusion yield, producing a target gain G=1.5±0.1 exceeding unity for the first time in a laboratory experiment [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe the experimental evidence for the increased drive on the capsule using additional laser energy and control over known degradation mechanisms, which are critical to achieving high performance. Improved fuel compression relative to previous megajoule-yield experiments is observed. Novel signatures of the ignition and burn propagation to high yield can now be studied in the laboratory for the first time.