Design of the first fusion laboratory experiment to achieve target gain > 1

The inertial fusion community have been working towards ignition for decades, since the idea of inertial confinement fusion (ICF) was first proposed by Nuckolls, et al., in 1972. On August 8, 2021 and Dec 5th 2022, the Lawson criterion for ignition was met and more fusion energy was created than laser energy incident on the target at the National Ignition Facility (NIF) in Northern California. The first experiment produced a fusion yield of 1.35 MJ from 1.9 MJ of laser energy and appears to have crossed the tipping-point of thermodynamic instability according to several ignition metrics. Building on this result, improvements were made to increase the fusion energy output to >3MJ from 2.05 MJ of laser energy on target, resulting in target gain exceeding unity for the first time in the laboratory. This result is important in that it proves that there is nothing fundamentally limiting controlled fusion energy gain in the laboratory. The presentation will detail the changes made to achieve this result.

Speaker: Annie Kritcher, Lawrence Livermore National Lab