Posted on 02/07/2024 6:58:26 AM PST by Red Badger
(Jacob Long/Lawrence Livermore National Laboratory) In December 2022, scientists at the US National Ignition Facility announced a historic milestone: for the first time, their laser-powered fusion reaction had 'broken even', producing more energy than it consumed.
But advances as big as this need to be rigorously checked – and that can take some time.
Importantly, a series of papers detailing the experimental design, technological advancements, and results of the initial breakthrough reaction have just passed peer review, meaning researchers not involved in the work have vetted the methods and findings in order to check the sums.
"This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible," the team members of the Indirect Drive ICF (inertial confinement fusion) Collaboration write in the first of five papers.
Nuclear fusion, if harnessed and scaled up, promises an abundant, inexhaustible source of clean energy without the greenhouse gas emissions of fossil fuels or the radioactive waste of nuclear fission. Fusion is the merging of two or more atoms to form a larger atom, releasing energy in the process.
These lab-based reactions are a far cry from commercial-scale applications, mimicking the fusion reactions powering our Sun and stars on a tiny scale. Without the Sun's mass to provide some gravitational grunt, methods for fusing atoms on Earth rely on heat.
In the case of this particular fusion technology, that heat is delivered via a powerful burst of light. The experiments involve bombarding a capsule containing a measly 220 micrograms of deuterium and tritium fuel with 192 high-powered lasers, which raises the pressure to 600 billion atmospheres and the temperature to 151 million °C (272 million °F).
These conditions, which far exceed those inside the Sun, cause the fuel to implode, the deuterium and tritium atoms fusing into helium and unleashing energy.
In the breakthrough experiment of December 2022, lasers fired 2.05 megajoules (MJ) of energy into the fuel, resulting in 3.15 MJ being released – so roughly 1.5 times more energy was produced by the reaction than was delivered into the fuel.
The new papers detail the progress that made 'breaking even' possible, including tinkering with the fuel mix, eliminating defects in the capsule walls, increasing the mass of the pea-sized capsule, boosting laser energies, and upping the volume of fuel used.
Passing that so-called ignition threshold heralded a new era of fusion research, which hasn't slowed down since: researchers have fired more energetic lasers and produced even more energy in several experiments last year.
The researchers also report results from one of those more recent experiments, from mid-2023, which generated 3.88 MJ of energy from the same 2.05 MJ energy input – about 1.9 times the energy injected, which is the highest yield to date.
Bear in mind, however, that huge amounts of energy are used to power the lasers in these experiments: 500 trillion watts, or a thousand times more power than the US national energy grid produces at any instant. So there's a long way to go before these fusion reactions actually generate more energy than goes into setting them off.
"There is a chance that we will have fusion," Martin Freer, a nuclear physicist at the University of Birmingham, told New Scientist's Matthew Sparks. "But the challenges that we have are pretty steep, scientifically."
Despite its promise of clean energy, scientists also stress that nuclear fusion is not the immediate solution we need for the climate crisis.
Commercial nuclear fusion facilities are still decades away, says University of Manchester nuclear fusion researcher Aneeqa Khan, when we need to almost halve global carbon emissions in the next 6 years – by 2030 – to turn the climate around.
Luckily, we already have the renewable energy technologies to do that.
The five papers have been published in Physical Review Letters, which you can read here, here, here, here, and here.
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.065102
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.025204
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.065103
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.065104
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.025203
Wait! Fusion power is now! I am waiting for the gov’t to mandate all fusion powered cars by 2035 - I am certain California will amp up the ante to 2030. Expect to replace all the effective measures put in place by green energy projects for the ultimate in green energy. What are they waiting for? Now we can protect all the birds we are chopping out of the air with turbine blades and frying mid-flight with solar farms. Perhaps it will reduce enough carbon emissions that farming will be allowed by then.
“-powering the lasers”
Just one stage of the laser amplifier is less than 50% efficient. I would not be surprised that the input might be 10x the delivered energy.
“powering the confinement scheme”
Zero. Inertial confinement.
Thanks Red Badger.
The Strange History
of Fusion and
the Science of
Wishful Thinking
by Charles Seife
“Thorium which has a benign decay series.”
Concerning stochastic radiation damages, thorium-232 is more radiotoxic than uranium if incorporating the same activities.
https://link.springer.com/article/10.1007/s00204-023-03484-6
Experiments run by Department of Defense aimed at proving, in a tangential way, the US knows how to make fusion bombs. The use of lasers in a batch process has no scalable means to usable electrical power, EVER.
Philo Farnsworth invented the Farnsworth Fusor in the early 1960’s. It created fusion using Cathode Ray Tubes instead of lasers. Unfortunately, Farnsworth died before he came close to breakeven energy.
You don't seem to understand what "break even" means.
“You don’t seem to understand what “break even” means.”
I understand what break even means. I don’t understand what you mean. Sarcasm?
Anything is better than that Tokamak crappola. I still claim it was a parting gift from the USSR to spoil US research.
It has certainly been nothing more than a money dump.
I wonder what the energy output ratio needs to be in order to engineer a self sustaining system. At 2:1 output to input it seems the scale would have to be impractically massive to cover all the inefficiencies in systems necessary to convert output heat to electricity and keep powering the Laser.
.
Natural fusion in the heart of stars requires massive amounts of gravity.
The will not achieve the required energy output with lasers.
Magnetism, maybe, but not lasers............
My last job before I retired was with NIF
Did they ever ignite?..............
Ha, ha, ha. Great Joke. I wasn't aware that "Science Alert" was a humor magazine. It makes sense, considering some of their global warming stories.
Apologies.
“Forgot the word “more” before the word benign.”
More correct is less benign.
I did some digging and found the LLNL lasers are 1% efficient and require an entire day to cool after producing the 1 excess MJ. So really they put in 200 mega joules to get 3 out.I share your skepticism on viability as there are huge engineering challenges in laser efficiency but this is still a major hurdle overcome especially considering their yield increased from the first experiment.
Warp Drive or bust.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
