Nuclear Fusion

Flyaway

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AI will help solve problems with nuclear fusion or so at least the US Federal government seems to believe.


The world’s largest nuclear fusion project began its five-year assembly phase on Tuesday in southern France, with the first ultra-hot plasma expected to be generated in late 2025.

The €20bn (£18.2bn) Iter project will replicate the reactions that power the sun and is intended to demonstrate fusion power can be generated on a commercial scale. Nuclear fusion promises clean, unlimited power but, despite 60 years of research, it has yet to overcome the technical challenges of harnessing such extreme amounts of energy.


And on a different tack.

 
1965 was an eventful year (my beloved TSR2 got canned) but it also marked the opening near my home town of Oxford of another futuristic project.
Reading this, it seems another of my lost futures along with Syd Mead's cars and the Boeing SST.
 
Researchers find unexpected electrical current that could stabilize fusion reactions

Electric current is everywhere, from powering homes to controlling the plasma (link is external) that fuels fusion (link is external) reactions to possibly giving rise to vast cosmic magnetic fields. Now, scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have found that electrical currents can form in ways not known before. The novel findings could give researchers greater ability to bring the fusion energy that drives the sun and stars to Earth.


Related journal article:

 
It reminds me:
As of today, about five years since Lockheed's public revelation of the cold fusion project, Lockheed is working on its "T4B" test reactor. That sounds pretty good -- about halfway through a 10-year project, you'd probably expect Lockheed to be on test reactor four or five right about now.

But here's the (other) thing: According to AW, Lockheed's T4 reactor was actually tested "in 2014-2015" -- in other words, the year Lockheed initially unveiled the project, it was already on its fourth iteration of the test reactor.
 
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So how does this “we’ll have it sorted in five year” plan deal with neutron embrittlement of the highly loaded reactor structure? This is a fundamental problem with all the Tokamak schemes. It means that even if a demonstration was successful of say sustained net energy output for the easiest D/T fusion reactions a multi billion dollar power plant would have a safe operational life of just a few years.... hopelessly uneconomic. A while back there was talk of switching to the He3/T reaction because it has lower neutron flux...... all we need to do is mine the closest source of bulk He3 .....that’ll be the moon.

I‘m similarly skeptical about SPARC’s claims due to my memories of reading fusion articles/plan in the late eighties claiming it would be cracked within a decade because they knew enough to do it;- I suspect 40 years after these claims still no one does.

Still best of luck to em.
 
Stupid question here but couldn't you just put neutron absorption tiles (or reflectors) between the plasma and the structural portion of the tokamak?
 
The problem is Fusion produces fast neutron which are difficult to effectively absorb. Here’s an explanation;-


This is also a problem for fission reactors as well which can be solved by running a continuous temperature profile which repeatedly anneals the pressure vessel steel, thus softening back to its design state. The problem with doing this in a fusion reactor is a lot of the highly loads structural parts within the neutron flux are not at the sorts of temperatures that anneal.
 
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Well the Sun is a fusion reactor.;)


Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun

Abstract
For most of their existence, stars are fuelled by the fusion of hydrogen into helium. Fusion proceeds via two processes that are well understood theoretically: the proton–proton (pp) chain and the carbon–nitrogen–oxygen (CNO) cycle1,2. Neutrinos that are emitted along such fusion processes in the solar core are the only direct probe of the deep interior of the Sun. A complete spectroscopic study of neutrinos from the pp chain, which produces about 99 per cent of the solar energy, has been performed previously3; however, there has been no reported experimental evidence of the CNO cycle. Here we report the direct observation, with a high statistical significance, of neutrinos produced in the CNO cycle in the Sun. This experimental evidence was obtained using the highly radiopure, large-volume, liquid-scintillator detector of Borexino, an experiment located at the underground Laboratori Nazionali del Gran Sasso in Italy. The main experimental challenge was to identify the excess signal—only a few counts per day above the background per 100 tonnes of target—that is attributed to interactions of the CNO neutrinos. Advances in the thermal stabilization of the detector over the last five years enabled us to develop a method to constrain the rate of bismuth-210 contaminating the scintillator. In the CNO cycle, the fusion of hydrogen is catalysed by carbon, nitrogen and oxygen, and so its rate—as well as the flux of emitted CNO neutrinos—depends directly on the abundance of these elements in the solar core. This result therefore paves the way towards a direct measurement of the solar metallicity using CNO neutrinos. Our findings quantify the relative contribution of CNO fusion in the Sun to be of the order of 1 per cent; however, in massive stars, this is the dominant process of energy production. This work provides experimental evidence of the primary mechanism for the stellar conversion of hydrogen into helium in the Universe.


 

Related paper:

The advanced tokamak path to a compact net electric fusion pilot plant

Abstract
Physics-based simulations project a compact net electric fusion pilot plant with a nuclear testing mission is possible at modest scale based on the advanced tokamak concept, and identify key parameters for its optimization. These utilize a new integrated 1.5D core-edge approach for whole device modeling to predict performance by self-consistently applying transport, pedestal and current drive models to converge fully non-inductive stationary solutions, predicting profiles and energy confinement for a given density. This physics-based approach leads to new insights and understanding of reactor optimization. In particular, the levering role of high plasma density is identified, which raises fusion performance and self-driven 'bootstrap currents', to reduce current drive demands and enable high pressure with net electricity at a compact scale. Solutions at 6–7 T, ~4 m radius and 200 MW net electricity are identified with margins and trade-offs possible between parameters. Current drive comes from neutral beam and ultra-high harmonic (helicon) fast wave, though other advanced approaches are not ruled out. The resulting low recirculating power in a double null configuration leads to a divertor heat flux challenge that is comparable to ITER, though reactor solutions may require more dissipation. Strong H-mode access (x2 margin over L–H transition scalings) and ITER-like heat fluxes are maintained with ~20%–60% core radiation, though effects on confinement need further analysis. Neutron wall loadings appear tolerable. The approach would benefit from high temperature superconductors, as higher fields would increase performance margins while potential for demountability may facilitate nuclear testing. However, solutions are possible with conventional superconductors. An advanced load sharing and reactive bucking approach in the device centerpost region provides improved mechanical stress handling. The prospect of an affordable test device which could close the loop on net-electric production and conduct essential nuclear materials and breeding research is compelling, motivating research to validate the techniques and models employed here.

 
This was surprising news to me, the UKAEA is drawing up nominations for a potential site for a STEP (Spherical Tokamak for Energy Production) fusion reactor for operation from 2040.
Kind of exciting to think the world's first fusion power station could be on my doorstep, but I wasn't aware fusion experiments had got that far to start thinking about building a prototype station in the next decade.

https://www.lancasterguardian.co.uk...tion-in-heysham-takes-one-step-closer-3270292

Edit: link fixed
 
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This was surprising news to me, the UKAEA is drawing up nominations for a potential site for a STEP (Spherical Tokamak for Energy Production) fusion reactor for operation from 2040.
Kind of exciting to think the world's first fusion power station could be on my doorstep, but I wasn't aware fusion experiments had got that far to start thinking about building a prototype station in the next decade.

https://www.lancasterguardian.co.uk/news/uk-news/proposal-to-build-worlds-first-fusion-power-station-in-heysham-takes-one-step-closer-3270292?fbclid=IwAR3r6SJb2iVBEI3lq51-a871P3v-Q1SSGrhwboLtrVqkr2rnhbdYFPEIFHk
I can’t get that link to open for some reason it says it cannot be found?

I did find this.

 
Yes, original link seems to be down at the moment.
It is back up now.
 
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National Ignition Facility experiment puts researchers at threshold of fusion ignition

On Aug. 8, 2021, an experiment at Lawrence Livermore National Laboratory’s (LLNL’s) National Ignition Facility (NIF) made a significant step toward ignition, achieving a yield of more than 1.3 megajoules (MJ). This advancement puts researchers at the threshold of fusion ignition, an important goal of the NIF, and opens access to a new experimental regime.

The experiment was enabled by focusing laser light from NIF — the size of three football fields — onto a target the size of a BB that produces a hot-spot the diameter of a human hair, generating more than 10 quadrillion watts of fusion power for 100 trillionths of a second.

“These extraordinary results from NIF advance the science that NNSA depends on to modernize our nuclear weapons and production as well as open new avenues of research,” said Jill Hruby, DOE under secretary for Nuclear Security and NNSA administrator.

The central mission of NIF is to provide experimental insight and data for NNSA’s science-based Stockpile Stewardship Program. Experiments in pursuit of fusion ignition are an important part of this effort. They provide data in an important experimental regime that is extremely difficult to access, furthering our understanding of the fundamental processes of fusion ignition and burn and enhancing our simulation tools to support stockpile stewardship. Fusion ignition is also an important gateway to enable access to high fusion yields in the future.

“This result is a historic step forward for inertial confinement fusion research, opening a fundamentally new regime for exploration and the advancement of our critical national security missions. It is also a testament to the innovation, ingenuity, commitment and grit of this team and the many researchers in this field over the decades who have steadfastly pursued this goal,” said LLNL Director Kim Budil. “For me it demonstrates one of the most important roles of the national labs – our relentless commitment to tackling the biggest and most important scientific grand challenges and finding solutions where others might be dissuaded by the obstacles.”

While a full scientific interpretation of these results will occur through the peer-reviewed journal/conference process, initial analysis shows an 8X improvement over experiments conducted in spring 2021 and a 25X increase over NIF’s 2018 record yield.

“Gaining experimental access to thermonuclear burn in the laboratory is the culmination of decades of scientific and technological work stretching across nearly 50 years,” said Los Alamos National Laboratory Director Thomas Mason. “This enables experiments that will check theory and simulation in the high energy density regime more rigorously than ever possible before and will enable fundamental achievements in applied science and engineering.”

The experiment built on several advances gained from insights developed over the last several years by the NIF team including new diagnostics; target fabrication improvements in the hohlraum, capsule shell and fill tube; improved laser precision; and design changes to increase the energy coupled to the implosion and the compression of the implosion.

“This significant advance was only made possible by the sustained support, dedication and hard work of a very large team over many decades, including those who have supported the effort at LLNL, industry and academic partners and our collaborators at Los Alamos National Laboratory and Sandia National Laboratories, the University of Rochester’s Laboratory for Laser Energetics and General Atomics,” said Mark Herrmann, LLNL’s deputy program director for Fundamental Weapons Physics. “This result builds on the work and successes of the entire team, including the people who pursued inertial confinement fusion from the earliest days of our Laboratory. They should also share in the excitement of this success.”

Looking ahead, access to this new experimental regime will inspire new avenues for research and provide the opportunity to benchmark modeling used to understand the proximity to ignition. Plans for repeat experiments are well underway, although it will take several months for them to be executed.

 

On another note:
 
Тheoretical experiments were made in the 1970s on paper that it is possible to detonate deuterium and tercium with the help of a laser but it is not yet known what type of laser light is needed to detonate it or elicit a reaction.that is, the frequency of light, maybe because that neutrino from the sun is examined to determine what type of light is needed ?

 
Cambridge, Mass. - September 8, 2021– Commonwealth Fusion Systems (CFS) and MIT’s Plasma Science and Fusion Center (PSFC) today announced the successful test of the world’s strongest high temperature superconducting (HTS) magnet, the key technology for a device that will unlock the path to clean commercial fusion energy for the world.
 
I am amazed y the capacity of those super magnets. I wonder if there is no other possible applications.
Does anyone knows where we can find some representative info on the total mass of the system and related physical characteristics?
 
There IS an application at least for 60 years of failed Tokamaks: hybrid them with MSREs.
As in: fusion-fission hybrids.

MSREs have some issues with tritium - and Tokamaks & fusion love tritium.
So feed the tritium to the fusion side of the reactor.

Meanwhile the Tokamak can handle some of its ultra-fast neutrons (from fusion), to the MSRE: for it to breed Thorium-232 into U233; U238 into U235 or Pu239.


The smart idea has been around since 1977 and the russians definitively seems to like it.


I like that idea but I have no idea if it makes any sense to our present and future energy needs and markets.

Anybody knows better ?
 
Stupid question here but couldn't you just put neutron absorption tiles (or reflectors) between the plasma and the structural portion of the tokamak?
Not really. Fast neutrons are hard to stop. They need several feet of concrete or similar to have much effect. That pushes the magic magnets away and makes their job more difficult. You can't use iron or lead because metals block the magnets even worse. And I'd hate to have to pump that much masonry down to a high vacuum.

There IS an application at least for 60 years of failed Tokamaks: hybrid them with MSREs.
As in: fusion-fission hybrids.
I like that idea but I have no idea if it makes any sense to our present and future energy needs and markets.

Anybody knows better ?
I'd expect to see how a viable Tokamak performs before I set about enhancing its efficiency with complicated and potentially dirtier additions.
 
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Just the new magnets alone was worth the price of admission…those might be useful for maglevs even if fusion doesn’t work out.
Who knows? Had CRTs been kept around and improved…something new might have come out of that.
 
I’ll take that over Malthusian Misrablists forcing us into sackcloth and ashes after cutting off our opposable thumbs and having us kneecapped so to lose our upright and bipedal stance like Greta wants…the Constitution replaced with the Unabomber Manifesto. When you get back to your cave, tell Alley Oop Gore I said hi, honey…

Fusion news


News
 
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