Lawrence Livermore National Laboratory is celebrating the yield from an experiment at the National Ignition Facility (NIF) of more than 1.3 megajoules of energy—eight times more than the yield from experiments conducted this spring and 25 times more than NIF’s 2018 record yield.
On August 8, researchers carried out a carefully designed experiment, focusing ultraviolet laser energy onto a target the size of a pencil eraser and generating more than 10 quadrillion watts of fusion power for 100 trillionths of a second. While a full review and interpretation of the results await, LLNL announced the conclusions of an initial analysis on August 17 and declared that researchers are at the “threshold of fusion ignition.”
Research mission: NIF, located at LLNL near San Francisco, Calif., began operations in 2009 as the world’s largest and highest-energy laser, with 192 powerful laser beams housed in a 10-story building the size of three football fields.
Ignition occurs when the energy released from the extreme heating and compression of fusion fuel is greater than or equal to the amount of energy absorbed by the fuel to start the fusion reactions. Experiments in pursuit of fusion ignition are an important part of NIF’s central mission: providing experimental insight and data for the National Nuclear Security Administration’s Stockpile Stewardship Program. Fusion ignition could also advance high-energy-density science and make it possible to use inertial confinement fusion as a power source.
“These extraordinary results from NIF advance the science that NNSA depends on to modernize our nuclear weapons and production, as well as open new avenues of research,” said Jill Hruby, DOE undersecretary for nuclear security and NNSA administrator.
The work of decades: “This result is a historic step forward for inertial confinement fusion research, opening a fundamentally new regime for exploration and the advancement of our critical national security missions,” said LLNL director Kim Budil.
LLNL reports that the record-breaking experiment built on advances developed in the past several years by the NIF team, including new diagnostics; target fabrication improvements in the hohlraum, capsule shell, and fill tube; improved laser precision; and design changes to increase the energy coupled to the implosion and the compression of the implosion.
“Gaining experimental access to thermonuclear burn in the laboratory is the culmination of decades of scientific and technological work stretching across nearly 50 years,” said Tom Mason, director of Los Alamos National Laboratory. “This enables experiments that will check theory and simulation in the high-energy-density regime more rigorously than ever possible before and will enable fundamental achievements in applied science and engineering.”
Mark Herrmann, LLNL’s deputy program director for fundamental weapons physics, said, “This significant advance was only made possible by the sustained support, dedication, and hard work of a very large team over many decades, including those who have supported the effort at LLNL, industry and academic partners, and our collaborators at Los Alamos National Laboratory and Sandia National Laboratories, the University of Rochester’s Laboratory for Laser Energetics, and General Atomics. This result builds on the work and successes of the entire team, including the people who pursued inertial confinement fusion from the earliest days of our laboratory.”
Work with lasers and inertial confinement fusion at LLNL began in the 1970s. More information about LLNL’s history is available online.