International
US nuclear fusion experiment could revolutionise clean energy─── 06:53 Wed, 14 Dec 2022
US scientists have carried out the first ever nuclear fusion experiment to achieve a net energy gain, paving the way for a "clean energy source that could revolutionise the world".
The experiment involved 192 high-powered laser beams being fired at a capsule containing the elements deuterium and tritium, heating it to a temperature of more than three million degrees centigrade - thus briefly simulating the conditions of a star.
During a news briefing, officials revealed the successful fusion experiment had taken place last week.
It was the result of "60 years of global research, development, engineering, and experimentation", which could eventually become the backbone of commercial electricity generation.
Such a result would supercharge the world's shift to renewable energy, helping to fight climate change.
US energy secretary Jennifer Granholm said the breakthrough "will go down in the history books".
"This is one of the most impressive scientific feats of the 21st century," she added.
While the target was smaller than a pea, the lasers are powerful enough to deliver more energy than the whole power grid sustaining all of the US.
How was the experiment carried out?
The experiment involved 192 high-powered laser beams being fired at a capsule containing the elements deuterium and tritium, heating it to a temperature of more than three million degrees centigrade - thus briefly simulating the conditions of a star.
Dr Marvin Adams said it had been carried out "hundreds of times before" but had never successfully produced more energy than was consumed.
"For the first time, they designed this experiment so that the fusion fuel stayed hot enough, dense enough, and round enough for long enough that it ignited, and it produced more energy than the lasers had deposited," he said.
"About two megajoules in, about three megajoules out - a gain of 1.5 - the energy production took less time than it takes light to travel one inch."
It was, as he quipped, "kind of fast".
How long before the process can create usable energy?
The question on everyone's lips following the news briefing was how long it would take before the process could be utilised for creating energy that we could actually use.
Dr Kim Budil, director of the Lawrence Livermore National Laboratory, admitted it would take "probably decades".
President Joe Biden has said he hopes a commercial fusion reactor will be in place within 10 years, and officials acknowledged that the private sector would have to play a big role in accelerating the shift from lab experiments to commercial electricity production.
