Fusion energy: Could powerful lasers power a working reactor?

Deep under the Nevada desert in the 1980s the US conducted secret nuclear weapons research.

Among the experiments was an effort to see if nuclear fusion, the reaction which powers the sun, could be sparked on earth in a controlled setting.

The experiments were classified, but it was widely known among physicists that the results had been promising, external.

That knowledge caught the attention of two young graduate students working at the Los Alamos National Laboratory in the late 2000s, Conner Galloway and Alexander Valys.

The Los Alamos lab was originally set up in 1943 as a top-secret site to develop the first nuclear weapons. Located near Santa Fe, New Mexico it is now a US government research and development facility.

“When Alex and I learned about those tests at Los Alamos, our reaction was like ‘wow, inertial fusion has already worked!’. Laboratory-scale pellets were ignited, the details were classified, but enough was made public that we knew that ignition was achieved,” says Mr Galloway.

Nuclear fusion is the process of fusing hydrogen nuclei together, which produces immense amounts of energy. The reaction creates helium and not the long-lived radioactive waste of the fission process which is used in existing nuclear power stations.

If fusion can be harnessed, then it promises abundant electricity, generated without producing CO2.

Those tests in the 1980s led to the US government building the National Ignition Facility (NIF) in California, a project to see if nuclear fuel pellets could be ignited using a powerful laser.

After more than a decade of work, in late 2022 researchers at NIF made a breakthrough. Scientists conducted the first controlled fusion experiment to produce more energy from the reaction than that supplied by the lasers which sparked it.