Around this time last year, a group of scientists conducted a historic experiment that yielded more than 1.3 megajoules of energy. After analysis, a team of scientists at the Lawrence Livermore National Laboratory in California confirmed that they had successfully achieved a nuclear fusion reaction that was energetic enough to sustain itself. This is an important step towards mimicking the chemical reactions that power the Sun and use the reaction as a source of energy.
However, one more hurdle remains to be overcome. This breakthrough was achieved on August 8, 2021 after decades of inertial confinement and fusion research. Since then, researchers have failed to replicate the experiment and get the same results.
In his experiment, the team National Ignition Facility (NIF) at Livermore focused laser light from the NIF on a target and produced 10 quadrillion watts of fusion power for 100 trillionths of a second. “The record shot was a major scientific breakthrough in fusion research, establishing that fusion ignition is possible in the lab in NIF,” said Omar Harikan, chief scientist of LLNL’s Inertial Confinement Fusion Program. He added that achieving the necessary conditions for ignition had been a long-standing goal and now opened access to a new experimental system.
According to LLNL physicist and lead experimenter Alex Zylstra, the lab conducted experiments in the burning plasma system in 2020 and early 2021. According to him, it set the stage for the historic experiment that was presented in August last year.
Since that day, the team has been busy conducting a series of experiments to replicate the performance and gain insight into the experimental sensitivity of the new regime. But, many factors can affect the performance of each experiment, making it difficult for the team to repeat the success.
“The 192 laser beams do not perform the same from shot to shot, the quality of the targets varies, and the ice layer on each target grows to different roughnesses. These experiments provided an opportunity to test and understand the variability inherent in this new, sensitive experimental regime,” explained LLNL physicist Anne Critcher.
Although the team has not been able to generate the same revenue as August last year, they are learning from the experiments. They are using the data collected so far to gain a deeper understanding of the fundamental processes of fusion ignition and burn.