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New New high-temp superconducting magnets for fusion
Welcome to Rivendell, Mr. Anderson.
New Well, I hope they don't run into to some unforeseen issue.
I remember talking to a PHD student at MIT in 1962 who was involved in a fusion project. I don't know how intense fusion research has been, but getting more energy generated than is consumed has been a problem.

"There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge."

-- Isaac Asimov
New Incremental progress is good.
That story is a bit over the top, though.

I did some looking around after seeing a version of that story. Japan has the record for magnetic fields at 1200T. MRI magnets are typically 30T. HTS magnets are certainly important, and this is good and important, but they're burying a lot of the context in chasing clicks.

It's still not clear what - if any - fusion concept will actually work, and if that concept will actually be economical.

Stronger magnetic fields have previously been achieved in outdoor experiments using chemical explosives, but this is a world record for magnetic fields generated indoors in a controlled manner. That greater control means the discovery could open new frontiers in solid-state physics, perhaps allowing scientists to reach what is known as the "quantum limit," a condition where all the electrons in a material are confined to the lowest ground state, where exotic quantum phenomena may appear.

The high magnetic field also has implications for nuclear fusion reactors, a tantalizing if unrealized potential future source of abundant clean energy. To reach the quantum limit or sustain nuclear fusion, scientists believe magnetic field strengths of 1,000 tesla or more may be needed.

The National High Magnetic Field Laboratory has several magnets over 20T.

Lots more work to do! Keep at it boffins!!1

New The title is a bit imprecise.
This new magnet was HTS, not low, so it can operate in a much smaller space. It only used 30 watts to get to 20T. It's the size and the energy draw for both the magnet and the coolant that's so revolutionary. The folks at MIT seem to think that this is going to be enough once it's ramped up.

ITER's magnets run at 13T.

With respect to the record of 1200T, that's for explosive compression and it only lasts a few dozen microseconds; not terribly useful for sustained fusion. :-)

I think you might have misread something: MRIs run around 3T and the largest approved for medical usage is 7T. The big research ones are around 10T and they require enormous magnets to work.
Welcome to Rivendell, Mr. Anderson.
New Touche'.
My division cells are not as quick as they used to be. ;-)

Progress is always good, but there are still vast unknowns.

Superconductors, and HTS, are flighty beasties, even without gigantic forces and neutron fluxes trying to destroy them.

And it's great that people are working on alternatives to ITER.

https://physicstoday.scitation.org/doi/10.1063/PT.3.3994 (from 2018)

CFS estimates that its burning-plasma device, SPARC, will cost around $400 million; the price tag for TE’s as-yet-unnamed device will be “a bit higher,” says Kingham. ITER will cost anywhere from $22 billion to $65 billion—the estimates provided by ITER’s management and the US Department of Energy, respectively.

Both companies say they have raised at least $50 million. TE’s investors include billionaire David Harding, founder of the Winton Group investment firm, and Legal & General, a financial services provider. The company has also received grants and R&D tax credits from the UK government.

CFS estimates it needs $100 million to meet its initial milestone: building full-scale prototype HTS magnets. To date, it has announced a $50 million investment from the Italian oil and gas producer Eni. CFS is not seeking government funding; rather, it is soliciting donors who will commit to the effort beyond the three-year magnet development phase, says chief operating officer Steve Renter. CFS will pay for ongoing R&D by MIT’s PSFC.

Building coils capable of generating a field in excess of 20 T at their surface will require the development of structural materials with higher strength than current stainless steels, according to a February report by DOE’s Fusion Energy Sciences Advisory Committee. Martin Greenwald, a CFS cofounder and deputy director of the PSFC, says engineers will have to restrain forces equivalent to weights of nearly 100 000 tons to prevent the D-shaped toroidal magnets from blowing up like a balloon, while also keeping the conductor from being stretched or bent and losing superconductivity. The magnets will also need to both resist and survive a quench, the condition in which superconductivity is suddenly lost and the magnetic energy is dumped. “Building this into a tokamak is a mechanical engineering challenge, taking into account the larger pressures that the coils are producing on themselves. When you double the field, the problem is four times harder,” says Whyte.


Assuming that the magnets will be successful and that further commercial funding can be raised, SPARC should take three to four years to build, Whyte says. If a burning plasma is then demonstrated, CFS would seek utility funding for a larger machine that would generate electricity. That device, which the company calls the affordable, robust, compact (ARC) reactor, would be about twice the size of SPARC and produce 200 MW of fusion power, roughly the output of a modern commercial power plant.

The ARC would feature a blanket of lithium-containing molten salt that would surround the vacuum vessel, carry away heat, and breed the tritium that’s needed to sustain fusion. Tritium does not occur naturally, but it can be bred from lithium by the fusion neutrons. The trick will be to breed sufficient amounts of the isotope and get it from the salt to the plasma. The fluorine-lithium-beryllium salt in the ARC would also absorb neutrons that damage the magnets over time. Even so, the neutron flux would limit the reactor lifetime to just nine years. The design features built-in joints in the coils and structure to allow for the vacuum chamber to be replaced every year or two.

While the YBCO (yttrium-barium-copper-oxide) superconductor works below 77K (liquid nitrogen temperature), in practice they operate it at 20K for various reasons, so they needed more than 30W to run this beasty (for the refrigerators - though to be fair it's much more for conventional (non high-Tc) superconductors). (Those two cylindrical things hanging off the flattened donut plane look like converted cryopumps - they typically get down to 10K and are well understood and off-the-shelf items. But they only have about 20-50W of heat capacity while requiring kW of electrical power themselves for the helium compressor. So it probably takes a long time to cool that thing down to 20K (and probably uses LN2 in other parts to speed the cooling).)

Neat stuff. But could still be another 30 years before we're getting power from fusion.


New Yep, most of the power is for coolant.
2 weeks to cool it down. There are definitely a lot more engineering problems to solve but this was one of the bigger ones.
Welcome to Rivendell, Mr. Anderson.
New Wonder how long it took to get that backronym

New Didn't they buy that ready-made from Sun?
New Stark Industries

     New high-temp superconducting magnets for fusion - (malraux) - (8)
         Well, I hope they don't run into to some unforeseen issue. - (a6l6e6x)
         Incremental progress is good. - (Another Scott) - (6)
             The title is a bit imprecise. - (malraux) - (5)
                 Touche'. - (Another Scott) - (4)
                     Yep, most of the power is for coolant. - (malraux)
                     Wonder how long it took to get that backronym -NT - (drook) - (2)
                         Didn't they buy that ready-made from Sun? -NT - (CRConrad) - (1)
                             Stark Industries -NT - (drook)

Better than an iron-shod boot to the head!
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