Brit boffins teach fusion plasma some manners with 3D magnetic field
- Reference: 1761046748
- News link: https://www.theregister.co.uk/2025/10/21/ukaea_fusion_plasma_magnets/
- Source link:
Working on the [1]Mega Amp Spherical Tokamak (MAST) Upgrade experiment at Culham in Oxfordshire, the UKAEA researchers used magnetic coils to apply the 3D magnetic field and stabilize the plasma.
In a fusion reaction, energy is produced by forcing light atomic nuclei, such as hydrogen, to fuse together to form heavier particles. Some of their mass is lost in the process, converted into a large amount of energy.
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To achieve this, the fuel needs to be confined at very high temperature within the tokamak to create a plasma, and this is difficult to control. If it becomes unstable, it can reduce performance or even damage the tokamak itself.
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Maintaining plasma stability is one of fusion's key challenges, and one reason for the old joke that fusion power is 30 years away – and always will be.
In general, a tokamak is a doughnut-shaped enclosure, but MAST adopts a more spherical form, "more like a cored apple," as its name suggests.
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According to the UKAEA scientists, their latest advance is in dealing with what they call edge localized modes (ELMs), instabilities that occur at the edge of a plasma cloud and could cause damage to the inner parts of a future fusion power plant.
The claimed first is in using resonant magnetic perturbation (RMP) coils, which apply a small 3D magnetic field at the plasma edge, to demonstrate complete suppression of ELMs within the MAST Upgrade machine.
"Suppressing ELMs in a spherical tokamak is a landmark achievement. It is an important demonstration that advanced control techniques developed for conventional tokamaks can be successfully adapted to compact configurations to develop the scientific basis for future power plants like STEP, the Spherical Tokamak for Energy Production," said UKAEA's head of MAST Upgrade Science, James Harrison.
[6]US tosses $134M pocket change at fusion pipe dream
[7]Physicist models new use for nuclear waste: Turning it into super-rare fusion fuel
[8]China claims major fusion advance and record after 17-minute Tokamak run
[9]Viable fusion power in a decade? Tokamak Energy dares to dream
STEP is a prototype fusion energy reactor, planned for construction on the site of a former coal power station in Nottinghamshire, which the UK government [10]allocated an additional £2.5 billion ($3.35 billion) in funding to earlier this year.
The researchers say they demonstrated another first – that they can independently control the plasma exhaust in the upper and lower divertors in MAST Upgrade, without impacting the performance or density of the plasma in the main chamber.
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These divertors direct particles and heat ejected from the plasma onto surfaces within the tokamak. Managing this exhaust is another key fusion challenge, and UKAEA claimed the ability to independently control the upper and lower divertors in a tokamak is another step toward ensuring the practicality of future power plant operations.
In the latest round of experiments, the team also achieved the best plasma shape ever recorded on the machine, with an elongation of 2.5, meaning the plasma height is 2.5 times its width. This is a positive development, we are told, and will be a key target for future fusion power plants.
The Culham Campus where the UKAEA facility is sited was also designated as the UK government's first " [12]AI Growth Zone " earlier this year. While these are intended to attract investment in AI-enabled datacenters and supporting infrastructure, Culham's role appears to be to develop fusion energy so the country stands a chance of powering all those bit barns – what some others are calling [13]high-tech "white elephants." ®
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[1] https://www.ukaea.org/work/mast-upgrade/
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aPeuFreKndxLgQSaS8xd-QAAAhY&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aPeuFreKndxLgQSaS8xd-QAAAhY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aPeuFreKndxLgQSaS8xd-QAAAhY&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aPeuFreKndxLgQSaS8xd-QAAAhY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[6] https://www.theregister.com/2025/09/11/us_fusion_power_funding/
[7] https://www.theregister.com/2025/08/18/physicist_nuclear_waste_fusion_fuel/
[8] https://www.theregister.com/2025/01/22/china_tokamak_plasma_record_claim/
[9] https://www.theregister.com/2024/10/16/tokamak_fusion_pilot/
[10] https://www.theregister.com/2025/06/13/uk_dumps_25_billion_into/
[11] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aPeuFreKndxLgQSaS8xd-QAAAhY&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[12] https://cities-today.com/uk-announces-first-ai-growth-zone/
[13] https://www.theregister.com/2025/02/12/uk_gov_ai_datacenters/
[14] https://whitepapers.theregister.com/
Re: Growth for me, not for thee
Well, promises and strategies are cheap, let's see how many of the promised billions in UK DC investments actually happen. If I were a decision maker at a hyperscaler then I'd want some modest footprint in-country plus I'd generously offer vague assurances that there's lots more investment available out round the back, purely to guarantee me political influence. But I'd be pretty reluctant to actually build a huge amount in the UK because our unit costs for infrastructure are double those of any sane country, and our industrial energy costs likewise.
Re: Growth for me, not for thee
"Foreign investment" isn’t what most people imagine. When a tax-dodging multinational boasts about “investing £50 billion in the UK,” it doesn’t mean a gift - it means they expect to extract at least £100 billion back. That return doesn’t appear out of thin air: it’s created by British workers, land, and resources. Only after that value has been siphoned off - and often routed through offshore entities - can we even start talking about tax revenue or “benefits to the economy.”
It’s essentially a leveraged PR exercise: promise billions, gain political capital, secure subsidies, cheap land, and infrastructure guarantees - then deliver a fraction of the headline figure while extracting long-term rents. The UK calls it “foreign investment”; the investors call it “colonisation with better branding.”
Re: Growth for me, not for thee
"The UK calls it “foreign investment”; the investors call it “colonisation with better branding.”"
Perhaps that's a bit sensationalist - the stock of UK inward FDI in 2023 was £2.1 trillion, that's the sum of everything them foreign businesses own of UK assets. The stock of UK outbound FDI in 2023 was £1.9 trillion that's what UK businesses own of foreign assets.
So, ignoring private investments and the smaller stuff that doesn't qualify as FDI, broadly speaking the UK has about as much invested overseas as overseas has invested here.
Re: "Foreign investment" (...) doesn’t mean a gift
Well, duh!
That's how "investment" works, you expect to profit from it. If not, it would be either a charitable donation (or aid) or just a money laundering scheme.
Re: "Foreign investment" (...) doesn’t mean a gift
That’s the part you’re missing - FDI isn’t free money, it’s a high-interest loan that doesn’t show up on the government’s balance sheet. The “investor” shoulders the risk, yes, but also locks in the right to extract profit for decades. It’s a short-term capital injection followed by a long-term drain.
When a local business invests, the money circulates - wages, suppliers, taxes - staying in the economy. When a foreign conglomerate does it, the profits are repatriated, subsidies are pocketed, and the net effect is capital flight dressed up as growth.
So now only 20 years away
Previously it was a whopping 20 years away.
Re: So now only 20 years away
The target moves a decade every decade.
Re: So now only 20 years away
You're both wrong. Go back fifty years and fusion power was thirty years away. So the target moves about eight years every decade.
Cynicism is easy
Definitely not an expert but from what little I know, this actually sounds like a big deal. I understand there are plenty of hard problems with Fusion but the main one always seemed to be plasma confinement and control - this sounds like a big step forward. So a tip of the hat from me.
Re: Cynicism is easy
" this sounds like a big step forward "
Yes, another of the sort of major breakthroughs that have made Culham hightly reputed for half a century or more. It remains to be seen whether its move into "AI" will maintain that reputation.
Re: Cynicism is easy
"... It remains to be seen whether its move into "AI" will maintain that reputation."
I'm reminded of some professor and a team of researchers at a place I used to work (Imperial College, London) who for a decade had been hammering away at theories about antibiotic resistance.
They seem to have got there in the end, but this spring they handed the problem to some AI thing, which figured it out in a couple of days.
I think everybody was impressed. Just the difference in the costs would be staggering, never mind the almost incredible speed of such an achievement.
https://www.bbc.co.uk/news/articles/clyz6e9edy3o
Yes, hallucinations are a thing. But we're just starting to crawl with all this stuff, let alone walk.
People who know me will tell you that I'll be the last person they'd expect to embrace the latest fad, whatever it is, but my feeling is that the nay-sayers should couch their pronouncements in very well-considered terms, so as not to look like dinosaurs in a few years' time.
Growth for me, not for thee
was also designated as the UK government's first "AI Growth Zone" earlier this year.
Preferential treatment for privileged and rich, sanctioned by the state like that should be illegal.
If growth zone is good for growth, they it should be accessible to all. If it is not good for all, but the privileged few, then I can smell the stench of brown envelopes.
Clowns.