Scientists achieve important step for nuclear fusion with 192 lasers

At the US National Ignition Facility, researchers have succeeded in generating a ‘burning plasma’ for the first time. That is an important step towards a fusion reaction that can provide energy. The plasma was sustained for a short time with energy from the fusion reaction itself.

For years, researchers from various institutes have been working on a way to generate energy with nuclear fusion, in which lighter elements fuse into a heavier element, releasing a large amount of energy. At the National Ignition Facility, part of the American research institute Lawrence Livermore National Laboratory, researchers have taken an important step: the production of burning plasma. To sustain a fusion reaction without supplying energy from outside, the plasma must be able to sustain itself with energy released from the fusion reaction. That has been achieved in the NIF.

The actual experiments with fusion were already realized in November 2020 and February 2021, with an experiment in 2021 yielding a record amount of energy. Nature is now publishing the results. During that fusion reaction, 1.3MJ of energy was released. To put that in perspective: 1.3MJ is about 0.36kWh and an average household burns about 10kWh daily. Moreover, the fusion reaction of the NIF is far from being energy-positive, since a lot of energy is needed to initiate the reaction. To this end, the lab employs 192 lasers, which compress a small pellet of deuterium and tritium until it reaches a temperature and pressure that allows fusion. The lasers consumed approximately 1.9MJ of energy for the test.

The research at the LLNL is not directly intended to develop a power plant based on nuclear fusion, but rather to gain insight into the processes that occur during, or shortly before, fusion. Nuclear fusion is being investigated in several research centers, with scientists also trying to develop fusion reactors for power plants. One of the best-known research institutes for the latter is ITER, in the south of France.

Cryogenic container of burning plasma during the experiments