Mark Hermann
Associate Director for Weapons and Physics Design for Strategic Deterrence
The achievement of fusion ignition at the National Ignition Facility (NIF) on December 5, 2022, has been called one of the most impressive scientific feats of the 21st century. While an important focus in the popular press has been on possible implications for a fusion energy future, a focus at Lawrence Livermore and inside the National Nuclear Security Administration has been the access this advance has given us to a new experimental regime that enhances our ability to ensure the safety, security, and reliability of our nuclear deterrent.
The achievement of ignition at NIF marks not just a milestone in inertial confinement fusion research, but the opening of a new scientific frontier. For the first time, we can routinely create and study environments in the laboratory that rival the extreme conditions found in stars and nuclear detonations. This capability was identified as a key goal from the beginning of the science-based Stockpile Stewardship Program (SSP) in the 1990s, and with its achievement we have significantly added to our capabilities to support the SSP.
In that first shot, and the eight ignition shots that have followed, we have obtained new data in the most extreme conditions we can create in the laboratory, providing experimental results that challenge our computational models in important new ways. These experiments are essential for understanding the behavior of multiphysics and nonlinear systems, and for testing key assumptions about how our systems will behave in response to extreme environments. With each shot, we push the boundaries of what is possible, and the data we collect will drive advances in both national security and basic science.
What is most exciting is that we have only just begun to explore this new regime. The questions we can now ask—and answer—are limited only by our imagination and the capabilities of our tools. As our diagnostic instruments, computational models, laser systems, targets, and physics insights continue to improve, so too will our ability to measure, understand, and control these extreme environments. The journey ahead promises discoveries that will shape our nuclear deterrent and enable technologies we have yet to envision.
This issue of Science & Technology Review looks at many facets of ignition research in the era beyond ignition. The feature article traces NIF’s path to ignition and describes the intense effort undertaken in a measurement campaign, which comprises a set of experiments proposed to answer key questions that can then set the stage for further advances or learning. Information gained over the course of a campaign, in which experimental parameters or target capsule features are changed to observe the resulting impact, can shape the success of future shots for many years ahead. The article concludes with a look ahead to NIF upgrades that could enable fusion yields several times what has been achieved to date.
The first research highlight focuses on the importance of supercomputing in the pursuit of ignition and higher yields and different ignition approaches. The development of landmark codes such as Lasnex and HYDRA have been essential to every step of progress in the ignition effort from the 1970s to today. The second research highlight delves into the array of sophisticated optical, x-ray, and neutron diagnostic instruments that enable us to learn from each shot—collecting shape, velocity, thermodynamic, and material-mix data from plasmas smaller than the width of a human hair—at the most extreme pressures and temperatures in the solar system for less than 50 trillionths of a second. The final highlight explores exciting work beginning to take on the many technological leaps required to realize fusion energy plants as well as the Laboratory’s collaborative efforts to forge a viable path for a fusion energy future.
The first achievement of fusion ignition will be etched forever in the history of science. This issue of S&TR looks beyond that momentous day—to its immense impact on the work that follows and forward to an ambitious ignition science course in support of our nuclear deterrent and more.
