NIF preamps are the first step in increasing the power of laser beams as they advance to the target chamber. Credit: Damien Jemison / LLNL
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The experiments conducted in August yielded a record yield of more than 1.3 megajoules.
After decades of self-confinement fusion research, a record-breaking 1.3 megajoules (MJ) yield of fusion reactions was first achieved in vitro during an experiment at the Lawrence Livermore National Laboratory (LLNL) National Ignition Facility (NIF) on Aug 8, 2021. These results are an 8-fold improvement over testing conducted in the spring of 2021 and a 25-fold increase over standard TIN returns for 2018 (Figure 1).
NIF directs, amplifies, reflects, and focuses 192 powerful laser beams onto a target roughly the size of a pencil eraser in a few billionths of a second. NIF generates target temperatures of over 180 million degrees Fahrenheit and pressures of over 100 billion in the Earth’s atmosphere. These extreme conditions cause the target’s hydrogen atoms to fuse and release energy in a controlled thermonuclear reaction.
Figure 1. This image shows the melt yield (MJ) from 2011 to date. credit: LLNL
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LLNL physicist Debbie Callahan will discuss this achievement during a plenary session in 63Research and Development Annual Meeting of the APS Plasma Physics Department. While there has been significant media coverage of this achievement, this talk will represent the first opportunity to address these findings and the way forward within the Scientific Conference.
Achieving such high yields has been a longstanding goal of self-contained fusion research and puts researchers on the threshold of fusion ignition, an important goal for NIF, the world’s largest and most energetic laser.
The fusion research community uses many technical definitions of ignition, but the National Academy of Sciences adopted the definition of “gain greater than unity” in a 1997 revision of the NIF, meaning that the fusion output is greater than the power of the ignition. laser provided. This experiment produced a fusion transfer rate of approximately two-thirds of the delivered laser power, which is very close to this target.
Experience is built on various developments developed by the NIF team over the past few years, including new diagnoses; Targeted manufacturing improvements to the capsule shell, filling tube and hohlraum (a gold cylinder holding the target capsule); Improved laser accuracy and design changes to increase power combined with blast and implosion pressure.
These developments open up access to a new experimental regime, with new research methods and the opportunity to measure the modeling used to understand the proximity of ignition.
Meeting: 63rd Annual Meeting of the APS Department of Plasma Physics
AR01.00001: Getting Burned Plasma In A National Laser Ignition (NIF)
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