Fusion breakthrough: ‘You can’t overstate how important this is’ says Queen’s physicist – but it is no ‘silver bullet’ for humanity

It was announced late on Tuesday that scientists at the USA's Lawrence Livermore lab had successfully carried out a controlled nuclear fusion test.

It is like the opposite of 'splitting the atom'; instead of breaking the tightly-bound particles in an atom apart (fission), scientists forcibly combine them (fusion), which releases a tremendous amount of energy – roughly four times as much as pure fission – using a relatively miniscule quantity of fuel.

It is the same process that powers the Sun, and has long been viewed as a potential source of abundant, clean energy – if only scientists could get it to work.

But so far the only real use for nuclear fusion has been as a bomb, largely because of the insanely-high pressures and temperatures needed to spark it.

The US Department of Energy revealed the news in a statement saying: "On December 5, 2022, a team from DOE's Livermore Lab made history by achieving fusion ignition.

"This breakthrough will change the future of clean power and America’s national defense forever."

Lab director Kim Budil said "fusion ignition in the laboratory is one of the most significant scientific challenges ever tackled by humanity, and achieving it is a triumph of science".

Prof Borghesi, the head of the Centre for Light Matter Interaction at Queen's University Belfast, dubbed it "a very important achievement" the significance of which "cannot be overstated, as potentially the first demonstration that energy production via inertial fusion is possible in principle".

But he added: "As for the direct significance for energy production, there is still a long way to go.

"The approach used [in this case] is very complex, and it is not clear at this stage that this can be easily adapted to the needs of commercial energy productions.

"These are all formidable technological and scientific challenges, which may take decades to solve (if a solution can be found)."

In 1952 American scientists discovered how to use a "small" nuclear bomb (a fission one, like those dropped on Japan) to set off a far bigger fusion bomb (also known as a hydrogen bomb).

The most powerful fusion explosion ever detonated was then detonated in the Arctic by the Soviet Union in 1961.

It was so extreme it reportedly created a mushroom cloud 59 miles wide and 42 miles high (several times higher than Everest) and blew out windows nearly 500 miles away – about the distance between the English coast and Berlin.

The energy generated in the US fusion experiment was utterly microscopic by comparison, and it took more energy to get the experiment going than it yielded once underway.

As such, Prof John Barry, a Queen's humanities academic and former Green Party co-chair, warned: "The scientists involved in the US experiment themselves are realistic about how fusion is not viable to meet immediate or even short-term energy demands.

"The successful experiment is confined to the laboratory, major problems remain to build fusion reactors to produce energy at scale, so this is not a ‘silver bullet’ technological solution to either our immediate energy crisis, or short-term requirements to decarbonise our energy and transportation systems in the next decade to achieve scientifically-determined climate change targets."

He said "there is a danger this this will be taken to mean we do not have to radically transform our economies" by reducing energy use and relying more on renewables.

"While of course we need to invest in energy research, a question we have to ask is how many homes could have been insulated for the cost of this experiment?" he added.

More from this reporter:

Academics keen to reinforce that climate change won’t spell sun and smiles for Northern Ireland