The US National Ignition Facility (NIF) has extracted enough energy from a
diamond capsule packed with hydrogen to keep the fusion reaction running for
the second time after its
historic fusion event in 2022.
Though it is still far from creating a stable, self-sustaining source of
electricity for the community, the repeat achievement is certain to give
important information on how to enhance the technology.
The NIF's experimental fusion program, based at the Lawrence Livermore
National Laboratory outside San Francisco, employs some of the world's most
powerful lasers to drive hydrogen atoms into new structures, leaving no
change in energy.
Obtaining an energy surplus has long been an aim of numerous fusion
technology inventors. Before fusion to occur in magnetically contained
whirlpools of plasma, the whirling maelstrom of tiny, charged particles must
be hotter than the Sun's core.
At the NIF, a small chamber the size of a fingernail filled with hydrogen
isotopes absorbs the rays emitted by 192 strong lasers to simulate the
identical circumstances. The nuclear particles that make up the isotopes can
then rearrange to generate helium (ideally with enough energy left
over).
The first milestone, known as ignition, happens when the released energy is
sufficient to keep the fusion process going.
Following the achievement of the necessary conditions in December, the NIF
has fueled its fusion engines in follow-up trials to determine whether they
can
enhance output any more.
"In an experiment conducted on July 30, we repeated ignition at NIF,"
the facility said in a recent Financial Times piece.
"As is our custom, we intend to report those findings at upcoming
scientific conferences and in peer-reviewed publications."
According to preliminary results, the overall output was 3.5 megajoules,
which is somewhat more than the 3.15 megajoules emitted by the December
ignition. The energy 'profit' appears to be amazing, with the lasers
delivering little more than 2 megajoules of energy. And it is if you need to
boil a few liters of water.
A fully working fusion plant based on NIF's technology will necessitate up
to 100 times more powerful lasers pulsating multiple times per second.
Scaling the system up to light roads, heat showers, and run air
conditioners for thousands of homes will necessitate many more ignition
events like this, each of which will disclose new methods to make the
process more efficient and controllable.
If realized, fusion power based on readily retrieved hydrogen isotopes
would theoretically liberate nearly infinite amounts of energy without the
radioactive waste problem of fission or the greenhouse-gas load of carbon
burning.
Every step closer to that reality is worth rejoicing over.
