\u201cWhat we\u2019re excited about with this model is the ability to explicitly make choices for future experiments that maximize our probability of success each time,\u201d study co-author Kelli Humbird<\/a> told Gizmodo during a video call. Even a facility as large and well-established as the NIF can only \u201cdo a couple dozen of these ignition attempts per year\u2014so really not very many at all, given how much territory we have to cover,\u201d added Humbird, who leads the Cognitive Simulation Group at NIF\u2019s Inertial Confinement Fusion Program<\/a>.\u00a0<\/p>\n Currently, nuclear power plants run on nuclear fission, which captures the energy generated by the splitting of heavy atoms, like uranium. Researchers eventually want to shift toward nuclear fusion, a process that combines lightweight hydrogen atoms to release massive amounts of energy. Fusion produces more energy and doesn\u2019t create harmful, radioactive byproducts, so having fusion as a reliable source of energy would greatly benefit our society\u2019s transition to sustainable energy. Although the field has made some promising advances<\/a>,\u00a0the consensus is that we\u2019re still far from implementing nuclear fusion on a commercial scale.<\/p>\n NIF\u2019s fusion experiments are laser-driven. First, the lasers heat up a gold cylinder called the hohlraum, which then emits a flow of powerful X-rays. The extreme temperatures compress the fuel pellets containing deuterium and tritium, two hydrogen isotopes used in fusion experiments. In an ideal scenario, this triggers enough deuterium-tritium fusion reactions to produce more energy than the lasers consume.\u00a0<\/p>\n Computer simulations can\u2019t reliably predict all the physics in this process, Humbird said. That\u2019s in part because the codes are often simplified so they\u2019re \u201ccomputationally tractable,\u201d but the simulations themselves can also introduce some errors. Even if you\u2019ve taken all sorts of precautions, it still takes days for the computers to finish running through the code, she added.\u00a0<\/p>\n Achieving nuclear fusion is like scaling a tall, uncharted mountain, Humbird said. The computer simulations are like an \u201cimperfect\u201d map that\u2019s supposed to teach researchers how to reach the peak\u2014but this map could be rife with errors that may or may not be the product of their research design. Meanwhile, the clock is ticking, and researchers have to quickly decide whether they\u2019ll take the hike that day and which tools they\u2019re going to use. And of course, each \u201chike,\u201d or ignition attempt, burns a huge hole in the budget.<\/p>\n And so, Humbird\u2019s team embarked on a mapmaking quest, stitching together \u201cpreviously collected NIF data, high-\u00adfidelity physics simulations, and subject matter expert knowledge\u201d to build a comprehensive dataset. Then, they uploaded the data to state-of-the-art supercomputers, which ran a statistical analysis lasting over 30 million CPU hours<\/a>.\u00a0<\/p>\n \u201cWhat we basically came up with was a distribution of things that go wrong [at] NIF,\u201d Humbird explained. \u201cAll of the different ways that we have observed implosions. Sometimes the laser doesn\u2019t fire exactly how you asked it to. Sometimes your target has defects in it that can cause things to not go super well.\u201d<\/p>\n![\"Nif](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/08\/nif-hohlraum-size-comparison-336x336.jpg\")
A NIF hohlraum. The hohlraum cylinder, which contains the NIF fusion fuel capsule, is just a few millimeters wide, about the size of a pencil eraser, with beam entrance holes at either end. The fuel capsule is the size of a small pea. Credit: LLNL\/NIF <\/p>\n