Experiment puts researchers on the brink of fusion ignition
On August 8, 2021, an experiment at the National Ignition Facility (NIF) of the Lawrence Livermore National Laboratory (LLNL) took an important step towards ignition, achieving an efficiency of over 1.3 megajoules (MJ). This breakthrough places researchers on the threshold of fusion ignition, an important objective of the NIF, and opens access to a new experimental regime.
The experiment was made possible by focusing laser light from the NIF – the size of three football fields – onto a BB-sized target that produced a hot spot the diameter of a human hair, generating more than 10 quadrillion watts of fusion power per 100 trillions of a second.
“These extraordinary results from the NIF advance the science on which the NNSA depends to modernize our nuclear weapons and production and open up new avenues of research,” said Jill Hruby, Under Secretary of State for Nuclear Security and Administrator of the NNSA.
The central mission of the NIF is to provide information and experimental data for the scientific inventory management program of the NNSA. Experiments in the pursuit of fusion ignition are an important part of this effort. They provide data in a large experimental regime that is extremely difficult to access, deepening our understanding of fundamental fusion ignition and combustion processes and improving our simulation tools to support inventory management. Fusion ignition is also an important gateway to enable access to high fusion efficiencies in the future.
“This result is a historic step forward for inertial confinement fusion research, opening up a fundamentally new regime for the exploration and advancement of our critical national security missions. It is also a testament to the innovation, ingenuity, commitment and courage of this team and the many researchers in this field over the decades who have consistently pursued this goal, ”said Kim Budil, director of LLNL. “To me, this demonstrates one of the most important roles of national laboratories – our relentless commitment to tackle the biggest and most important scientific challenges and to find solutions where others might be deterred by obstacles. . “
Although a full scientific interpretation of these results occurs as part of the peer-reviewed review / conference process, the initial analysis shows an 8-fold improvement over experiments conducted in the spring of 2021 and a 25-fold increase. compared to the record performance of the NIF in 2018.
“Obtaining experimental access to thermonuclear combustion in the laboratory is the culmination of decades of scientific and technological work spanning nearly 50 years,” said Thomas Mason, director of the Los Alamos National Laboratory. “This enables experiments that will verify theory and simulation in the high energy density regime more rigorously than ever before and enable fundamental achievements in applied science and engineering.”
The experience was based on several advances drawn from the knowledge developed in recent years by the NIF team, including new diagnostics; target manufacturing improvements in the hohlraum, capsule shell and fill tube; improved laser precision; and design modifications to increase the energy coupled to the implosion and the compression of the implosion.
“This significant breakthrough has only been made possible by the continued support, dedication and hard work of a very large team over many decades, including those who have supported the efforts of LLNL, industry and academic partners and our collaborators from the Los Alamos National Laboratory and Sandia. National Laboratories, the University of Rochester’s General Atom and Laser Energy Laboratory, ”said Mark Herrmann, deputy director of LLNL’s program for fundamental weapons physics. “This result builds on the work and successes of the entire team, including the people who pursued inertial confinement fusion from the early days of our lab. They should also share the excitement of this success.
For the future, access to this new experimental regimen will inspire new avenues of research and offer the opportunity to compare the modeling used to understand the proximity of inflammation. Plans for repeated experiments are well advanced, although it will take several months to be executed.