On 5 December, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) conducted the first ever controlled fusion experiment to produce more energy from fusion than the laser energy used to drive it - a breakthrough that has been decades in the making.
This is the first ever controlled fusion experiment to produce more energy from fusion than the laser energy used to drive it
Nuclear fusion is the process by which two light nuclei combine to form a single heavier nucleus, releasing a large amount of energy. LLNL has been pursuing the use of lasers to induce fusion in a laboratory setting since the 1960s, building a series of increasingly powerful laser systems at the California lab and leading to the creation of NIF, the world’s largest and most energetic laser system. The facility uses powerful laser beams to create temperatures and pressures similar to those found in the cores of stars and giant planets - and inside nuclear explosions.
The experiment used 192 laser beams to deliver more than 2 million joules (MJ) of ultraviolet energy to a deuterium-tritium fuel pellet to create so-called fusion ignition. In achieving an output of 3.15 MJ of fusion energy from the delivery of 2.05 MJ to the fuel target, the experiment demonstrated for the first time the fundamental science basis for inertial confinement fusion energy (IFE).
The fundamental science basis for inertial confinement fusion energy has been demonstrated for the first time
This breakthrough was announced in a press conference by the US Department of Energy (DOE) and the DOE National Nuclear Security Administration (NNSA).
US Secretary of Energy Jennifer Granholm said that this is "a landmark achievement for the researchers and staff at the National Ignition Facility who have dedicated their careers to seeing fusion ignition become a reality, and this milestone will undoubtedly spark even more discovery." NNSA Administrator Jill Hruby said that the experiment marked "the first tentative steps towards a clean energy source that could revolutionize the world."
The experiment marked the first tentative steps towards a clean energy source that could revolutionize the world
There are two main experimental approaches to nuclear fusion being studied at the moment
Inertial confinement (IFE) is one; the other one is magnetic confinement fusion, which uses strong magnetic fields to contain the hot plasma in a containment such as a tokamak (like the one being currently built at ITER). The US Administration earlier this year announced a "decadal vision" to accelerate fusion energy based on tokamak systems.
The foundational technology for magnetic fusion is more developed than for IFE, LLNL Director Kim Budil said, but NIF's achievement can be seen as "the fundamental building block" of an inertial fusion power system. "Very significant hurdles" in both science and technology remain to be overcome, but "with concerted effort, a power plant could be built in a few decades", she said.
With concerted effort, a magnetic confinement fusion could be built in a few decades
Source: World Nuclear News