Scientists at Lawrence Livermore National Laboratory (LLNL) and the National Ignition Facility (NIF) have reportedly advanced last December’s laser fusion breakthrough result. For the second time, scientists obtained more energy from a fusion reaction than the process consumed — achieving a so-called net energy gain. Results were reported Sunday in the Financial Times. Media outlets including The Washington Post, The Guardian, and Bloomberg also shared the news. Initial reports indicate that the reaction occurred July 30 and returned more energy than the December reaction. Fusion — both laser-based (inertial confinement fusion) and magnetic confinement fusion — is widely viewed as a vital source of green energy for the future global power grid. In addition to their efficient generation of power, fusion reactions do not produce long-lived radioactive waste, according to the International Atomic Energy Agency. To begin to tap into fusion’s promise, efforts in research and industry have ramped up in the last decade to chart a course for commercialization. The December 2022 NIF result served to reinvigorate the global fusion community by achieving a pursuit that scientists in the U.S. and elsewhere had sought for nearly 70 years. LLNL and NIF scientists have reportedly obtained more energy from a fusion reaction than scientists were able to generate in a breakthrough December 2022 result. The reported net energy gain marks the latest milestone in a quest that would help advance fusion toward commercialization — something that most experts believe remains years from reality. Courtesy of LLNL. In the wake of December’s result, the scientific community has continued to caution that commercial fusion power and fusion power stations likely remain decades from practical implementation (see Nuclear Fusion Drives Laser Development, Photonics Spectra, April 2023, p. 24). However, repeatability of an experiment yielding a net energy gain marks a separate advancement that builds on recent momentum. The successful December experiment and fusion reaction released 3.15 MJ of energy from an input 2.05 MJ. While the extent of NIF’s efforts to replicate and build on that result this year are not immediately known, the facility has previously detailed the difficulty in replication. For example, last summer, NIF proved unable to re-create a 2021 experiment that brought the group to the cusp of ignition. Arthur Pak, team lead for stagnation science and the lead for diagnostics on the celebrated December 2022 experiment, said that the NIF team attempted to repeat the 2021 experiment at least three times. Reports on those experiments stated that the attempts delivered no more than 50% of the energy output recorded in 2021. Variables that influence a net gain from an inertial confinement fusion reaction include those to the fusion target, optics and optical equipment, laser system, and more. The LLNL and NIF team has yet to detail the July 30 result. Early coverage of the advancement suggests that the lab will report its results in full following a peer-review process. The latest LLNL-NIF result boosts a wave momentum already ripping the commercial fusion sector this summer — with laser fusion companies among the recipients of government and private funding. Blue Laser Fusion (BLF) raised $25 million last month in a seed funding round to expand R&D operations in the U.S. and Japan. The company is led by a group that includes 2014 Nobel laureate and laser luminary Shuji Nakamura. U.S.-based Focused Energy and Xcimer Energy both received funding from the Energy Act of 2020, while Japanese laser fusion company EX-Fusion recently closed an oversubscribed ¥1.8 billion ($12.8 million) seed round. And Colorado State University and Marvel Fusion, a German startup, have agreed to build a $150 million laser facility in Fort Collins, Colo.