US scientists have conducted the first nuclear fusion experiment to achieve a net energy gain, paving the way for a “clean energy source that could revolutionize the world.”
During a historic press conference at the Lawrence Livermore National Laboratory in California, officials revealed that the successful fusion experiment had taken place last week.
As It Happened: ‘Amazing’ Scientific Breakthrough Could Create Unlimited Energy
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 an outcome would drive the world’s shift towards renewable energy, helping to combat 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,” he added.
How was the experiment carried out?
The experiment involved 192 high-powered laser beams fired at a capsule containing the elements deuterium and tritium, heating it to a temperature of more than three million degrees Celsius, 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 would stay hot enough, dense enough, and round enough for long enough for it to ignite and produce more energy than the lasers had deposited,” he said.
“About two megajoules in, about three megajoules out, a gain of 1.5, the power output took less time than it takes light to travel one inch.”
It was, as he joked, “a little fast.”
High-powered lasers were used, converging on a target “the size of a peppercorn”.
While the target was smaller than a pea, the lasers, part of the so-called NIF system, are powerful enough to deliver more power than the entire power grid that powers the entire US.
Chief engineer Jean-Michel Di Nicola said it was “the size of three football fields and delivers energy of more than two million joules with a peak power of 500 trillion watts.”
“For a very short period of time, a few billionths of a second, it beats the entire US power grid,” he said.
The NIF system has 192 lasers
How long before the process can create usable energy?
The question on everyone’s lips after the press conference was how long it would take before the process could be used to create energy that we can actually use.
Dr. Kim Budil, director of the Lawrence Livermore National Laboratory, admitted that it would take “probably decades.”
President Joe Biden has said he expects a commercial fusion reactor to be installed within 10 years, and officials acknowledged that the private sector would have to play a major role in accelerating the shift from laboratory experiments to commercial electricity production. .
Other nuclear fusion projects will also have a role to play, and the California scientists cited the work of an Oxfordshire team, which earlier this year used his JET machine to generate about 11 megawatts of power.
That was much more than was generated in the NIF experiment, but more importantly, it did not achieve a net energy gain.
A significant scientific milestone, but lasers require great power
As Dr. Marv Adams held the cylindrical target containing the “peppercorn-sized” pellet of fusion fuel, he confirmed that they had successfully “ignited” a fusion reaction.
It also revealed that the scientists put about 2MJ of energy into their fusion reaction and took out about 3MJ.
That is the evidence of the “energy gain” that this ad is about.
That’s the significant scientific milestone: proving that a fusion reaction itself can generate more energy than you put into it.
But they had to use 300 MJ of electricity to power up their lasers.
So from a power output standpoint, they still have to put 99% more power into the machine as a whole as they go out.
Oxford University professor Gianluca Gregori, a specialist in the type of lasers used in the laboratory, noted that the amount of energy produced was less than that needed to power a wall socket.
“While this is not yet an economically viable power plant, the path for the future is much clearer,” he added.
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Jeremy Chittenden, professor of plasma physics at Imperial College London, said scientists “will have to find a way to reproduce the same effect much more frequently and much cheaper.”
If they do, it would be a great boost to the global drive towards renewable energy.
