August 8 was a momentous day for nuclear fusion in the US, as an experiment at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory made a leap towards the threshold of “ignition” of inertial confinement fusion.
This approach differs from the magnetic confinement seen in fusion reactors across the world such as Tokamak and Stellarators. Energy is not extracted by a continuous flow of extremely hot fusing plasma – in inertial confinement, fusion instead is extracted from discrete events. Small pellets of fuel are ignited by heating and compressing, creating fusion and releasing a huge amount of energy that can be turned into electricity.
For fusion to be self-sustaining – getting more energy out than put in – it has to surpass the fusion ignition threshold. Data from the recent test at NIF is still being analyzed, but it appears to be right at the cusp. It released 1.3 Megajoules of fusion energy – an eight-fold improvement on the test conducted this past spring, and 25 times better than the record-breaking experiments in 2018.
The facility is the size of three football fields and uses lasers on a very small target. As it is heated, it creates a hot spot the diameter of a human hair, releasing 10 quadrillion watts of fusion power for 100 trillionths of a second.
“Gaining experimental access to thermonuclear burn in the laboratory is the culmination of decades of scientific and technological work stretching across nearly 50 years,” Los Alamos National Laboratory Director Thomas Mason said in a statement. “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.”
Nuclear fusion could revolutionize energy production by allowing for more energy without radioactive waste products, dangerous aerosols, or greenhouse gases emissions. Full-scale nuclear fusion power plants are being built already to test their viability.
If inertial confinement fusion can be finally achieved, it could be used to produce different types of nuclear fusion power plants. It can also allow the study of extreme physical environments where heat and pressure are incredible.
However, it’s not just about civil uses. In the United States, the NIF has a role in the nuclear weapons Stockpile Stewardship program.
“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.