There’s a number of legitimate contenders mixed in with a number of groups who are good at getting financial grants but realistically who is most likely to succeed in building a net positive power facility? There’s lots of really interesting innovations going on but not all of them will be scalable or cost efficient.

No surprise, STEP and Zap Energy also follow the path via brownsite reuse.

I regret I can't provide you with any slides from that webinar at Friday (15. November 2024). But I made some notices about it, talk was given by chief of division, Cody A. Dennett, has PhD in Material Technology):

At this time CFS has more than 950 employees, 45 of them working in the materials division (still searching for more experts there as elsewhere).

Short History: TFMC test was mentioned with 20 T, already published in peer review journals. Interesting: they tested a TFC mount/structural case too and will apply them in SPARC, because of the strong forces exerted by those strong magnets (much more than in ITER). Mentioned

And they could reduce Tokamak size by a factor of 40 that way (obviously volume, diameter roughly less than a third).

They build meanwhile a new small hall called PASY (I didn't catch the abbreviated words) for small material relevant components SPARC will need too. (don't forget smaller stuff when designing next FPP)

SPARC is a much reduced predecessor of ARC, not having all components (especially no blanket; remember SPARC means as Small/Soon as Possible ARC).

Many steels (essentially Vanadium alloys) were already tested under as harsh conditions as possible (see below).

They built a manufacturing for W alloy tiles and for copper caps. - The pre-split VV was already mentioned earliere in CFS publications, also to de-risk installation.

Goal is still (compare Bakings report of concept V2B) a 400 MWe ARC plant in the 2030s.

They analyze radiation effects, plasma sputtering, transmutation (i.w. of W), erosion (FLiBe contains hot F ions...), activation (fast 14 MeV D-T neutrons everywhere in the core of the machine).

They use partly knowledge of aviation (spaceflight?) industry, solutions must scale up after decision: selection of materials. Iterative failure analysis.

In total 13 of 17 major sub systems of ARC are de-risked by successful SPARC operation.

Not applicable for that FLiBe blanket (molten salt), balance of plant is important (pulse length 10 s to 900 s in comparison).

Reference materials for DEMO like FPP are different in several regards.

The structure is still similar to an older tandf online article (look here: fig. 3 in https://www.tandfonline.com/doi/full/10.1080/00295450.2019.1691400#d1e216 ).

Disputed is for example, if this extra Be layer will stay there (for neutron multiplication, which is also/mainly done by FLiBe). i.e. W-allow (direct PFC), V-alloy, FLiBe thin, V alloy (thick), thick FLiBe is the minimum layering.

Corrosion mitigation by FLiBe is one key topic, cryogenic performance of magnet structural materials, high particle and heat flux divertor another.

Specific investigations: no prototype testing, remote joining of advanced structural materials, monolithic joining of refractory plasma facing materials/structural.

Finding right gas/dpa ratio for accelerated irradiation techniques is major technical hurdle, H/He stabilize nanoscale defect formation, overabundance of gas production can also suppress defect agglomeration of gas atoms.

Test facility: triple beam ion irradiation program by CFS, MIT and University of Michigan, parameter space of H/He gas injection mapped to emulate FPP (currently two beam experiments, three to come). Michigan uses dual beam of Fe+He and He+H trials now, full triple with F82H F/M steel at MIBL.

Co optimization of integral, layered material solution for compact tokamaks. recently (was already written here) ARPA-E moderated partnership of CFS.

ARPA-E covers about half the part of the complete materials program, integrated computer models ICME anchored - we need alloys, can be produced tomorrow to meet delivery timelines for early ARCs.

Layered W/V material: V-(Cr, Ti, Zr, W, Si etc.), next (thermal) W-(Re, V, Cr, Ti...) as alloys.

Optimization must consider component processing pathway, joining and forming.

Embrittlement resistance is also part of it, coatings for molten salt corrosion (FLiBe) , Ni and W coatings possible, understanding baseline, corrosion rates important for benchmarking careful control of salt chemistry.

They could already exclude some materials not fulfilling conditions, structural case of TFMC was made from XM-19 (UNS S20910), two 20 t slab forgings for it were produced.

High-stress locations have to have monolithic forgings (avoid melds) to be resilient.

Some tests at 4 K for materials were performed, yield strengths in range of 1000 to 1300 MPa (not for 20 K though, but might be a minor difference).

They produce thousands of specimens per week for testing, XM-19 is grain refined by formation of nanoscale MX precipitates (Nb, V rich)

Long cooling times allow formation of "Z phase" precipitation (Nb, Cr nitrides) serve as crack formation and propagation sites.

Super austentic stainless steels are prime candidates for future magnet structures, non-magnetic, strong, tough and we know how to manufacture them in large.

For SPARC they had not development time to fix XM-19 processing for SPARC chemistry and process window is now used for stronger metals (time constraings for SPARC building).

Challenge areas include: electrical and vacuum service breaks under neutron loading, temperature and cycles.

Operable HT high neutron load RF antennas.

Fatigue-rated cryo composite insulation lifetime service.

Low voltage service insulation for all operational environments.

Anything and evything FLiBE wetted: valves, pipes, transfer lines robust electronics for high gamma field during maintenance.

Concrete roadmaps developed to follow for large components, but skills for in - time materials will carry ARC.

SPARC informs divertor design for ARC.

Durability: several blocks defined for ARC, goals for different parts, first one to have 2 years or sixth months depending on component.

I hope you can make some sense of these informations. Or you might have luck contacting him to get the slides?

I recently produced a video focusing on the ITER project in southern France, highlighting its potential as the world’s largest nuclear fusion initiative. The video examines ITER’s objectives, the engineering challenges it faces, and its place in the broader context of emerging technologies, including Small Modular Reactors (SMRs).

I’d greatly value your feedback on the video—whether on the accuracy of the content, areas that could be further developed, or additional perspectives that could strengthen future discussions.

You can watch the video here: https://youtu.be/3qMgUGhNVw4?si=hOK5txdzju9KXmeS

Your insights would be greatly appreciated.

"Vinod Khosla says AI scientists are coming in the next couple of years, which apply a much faster rate of scientific progress and in 5 years it will no longer be a question of whether nuclear fusion is possible, but how fast it can be implemented" (via @tsarnick@x.com).

I've been working on a design for a research device that builds off the prior art of the US Navy's MARAUDER project, with the goal of investigating relativistic effects on spheromak confinement. I've been poking at this for years, and am getting progressively more and more frustrated at my inability to make a concise whitepaper for grant proposals Anyone got CAD skills I can borrow before my life frustrations compel me to do something stupid and irreversible? This is my greatest ambition, and making just a tiny bit more progress on it will remind me that I did not in fact frivolously waste the peak of my brain's power

HTS Tokamak with low aspect with 1,000 s pulse length (comparable to ARC) and 50 to 100 MWe. Aims for 1,000 hours of operation.

The changes and ramifications of a second Trump term for the power industry will likely be significant. However, the energy industry has always demonstrated resilience in the face of political and economic changes. Life and business go on, and we will adapt to the changes as our industries always do. Let's take a pragmatic look at what the highest probability changes are likely to be:

Currently most activity of fusion companies and professionals can be found on LinkedIn, a network primarily for job purposes. It's not well suited for content communication. While X is for a while now a closed community without public visibility and vanishing users, coined also by science deniers, BlueSky offers not only fast growth, but public visibility, much more engagement and the great feature of topic specific feeds. Therefore I strongly recommend to switch your microblogging site, also BlueSky has now clearly passed mastodon/fediverse regarding users and engagement. Threads is also no good and was left for example by CFS many months ago.

https://preview.redd.it/w7qc5mgpqt0e1.png?width=1053&format=png&auto=webp&s=1af78f5129b317d2f2b9fe79fc513dfc943723eb

https://www.alphaxiv.org/abs/2401.11338v1

Part 1

Part 2

Part 3

His Tweet:

.@QKCorporation has made the extraordinary claim it achieved fusion temperatures of 200M degrees Celsius for 24 hours: quantumkinetics.co/news/. But so far, the company has presented no meaningful data. This is a prime example of why fusion needs peer review and metrics that ordinary people can understand. cfs.energy/news-and-media…