The US Department of Energy and the National Nuclear Security Administration (NNSA) have announced a success in a nuclear fusion experiment at the Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF). A system of 192 lasers emitted 2.05 megajoules of energy by focusing it on a tiny gold cylinder containing a pellet of deuterium and tritium. The energy from the lasers created conditions similar to those in a stellar core by triggering nuclear fusion and generating about 3.15 megajoules of energy. Obtaining more energy than emitted is an important step in using nuclear fusion as an energy source but a lot remains to be done to build fusion nuclear power plants.
Nuclear fusion is well-known from a theoretical point of view and is the basis of thermonuclear bombs. Controlling it could provide all the energy required in the world while eliminating the problems associated with fossil fuels. The problem is that for decades, progress has been very slow in experiments based on different technologies to be used to trigger nuclear fusion and contain the energy obtained. There were successes but the energy used to trigger the fusion was equal and often higher than that obtained. For this reason, obtaining more energy than that emitted in the experiment conducted on December 5, 2022, was an important step forward.
It must be said that the energy emitted calculated in the comparison is only that of the lasers but all the NIF equipment that runs the lasers consumed 322 megajoules of energy during the experiment. On the other hand, NIF wasn’t built as a nuclear fusion-energy device but to have the largest possible laser system for nuclear research.
Nuclear fusion experiments form part of NIF work and are also necessary for studies such as those on the conditions of heat and pressure that develop inside thermonuclear explosions. To get the necessary results, the system doesn’t have to be energy efficient but it does have to produce a lot of energy from the experiments.
The results of the December 5 experiment remain valid, but further steps will need to be taken before this technology can be used to produce energy to be used in homes. The energy obtained must increase significantly and a dedicated system should be much more efficient than NIF. The speed at which the lasers can generate the pulses must increase along with that of preparing the fusion chamber for the next pulse.
The more optimistic people have already criticized other experiments such as the International Thermonuclear Experimental Reactor (ITER) project in France, based on magnetic confinement. However, NIF success by no means implies that ITER is a failure and the same goes for other projects that haven’t yet had such important results. The Joint European Torus (JET) experiment, a precursor to ITER, produced 59 megajoules of energy in February 2022 within five seconds. In short, there are various advances obtained using different technologies and it’s not certain that only one of them will be used in the future.
In the 1970s and 1980s, it was said that it would take about 30 years to produce usable energy using nuclear fusion. Unfortunately, this result proved to be more complex than expected and important experimental results are only coming now. Investments are considerable all over the world but it will still take who knows how long to get to have nuclear fusion plants.
