Note: they did not achieve "commercial fusion" (Q-total > 1), they set a temperature record among commercial fusion companies. (Still cool though!)
When Q>1 times come, we will then have to assume Qtotal < 1 until explicitly mentioned. As there are losses along the way and heat must be converted to electricity.
There are IAEA reports for fusion calling for materials that survive >100 displacements-per-atom (DPA) and > 1000deg C[1]. Additionally you might also need highly controllable super-conducting magnets as well as advanced sensing of the instabilities of the fusion plasma to ensure they are well confined (a chief requirement for fusion). There are other problems, but these are typical issues with tokamak-based fusion devices. Chiefly most tokamaks around the world do not operate in "continuous mode", ie they operate on "shot mode" or short duration experiments to attempt to ignite the plasma to fusion conditions. Achieving high-duty cycle operation with a ignited plasma is its own hurdle.
Making hot plasmas is interesting, but if your technology requires the above, you are looking at around 4-5 once-per-decade material science results.
Every national lab in the US is saying we are out of time, we need existing energy solutions to avoid the worst of climate change.
Source: I am a nuclear engineer. [1] https://www.sciencedirect.com/science/article/pii/S136970210...
We certainly need to decarbonize as fast as we can without waiting for fusion, but if we're lucky then fusion might make things easier down the road.
The problem is that even 1 DPA is significant for structural materials, and is basically a nightmare for electrically or mechanically sensitive ones. For example light-water fission reactors achieve about 50 DPA to their reactor pressure vessels over their 40-50 year lifetime. Its hard to imagine that anything called a super-conductor could maintain Cooper-pairs after getting the average atom displaced from its original position.
Additionally CFS ran at 20 Kelvin... which again is hard to imagine happening at scales other than CERN-like efforts (ie one-of-a-kind installs):
"In September 2021 Commonwealth Fusion Systems (CFS) created a test magnet with ReBCO wires in which flowed a current of 40,000 amperes, with a magnetic field of 20 tesla at 20 K." [1]
Edit: Also magnets have 1/R^3 field die-away, in direct competition with 1/R^2 particle dispersion die-away.... meaning your magnets control better as you make cavities smaller, however it also means the magnets get much more DPA :(.
[1] https://en.wikipedia.org/wiki/Rare-earth_barium_copper_oxide
Materials are an ongoing problem, and it's not just dpa. Abdou at UCLA pretty convincingly argues that increasing dpa of wall materials isn't even the most pressing problem; reliability of the wall/blanket is.
http://www.fusion.ucla.edu/abdou/abdou%20presentations/2018/...
I should add that fusion neutrons add a problem beyond that experienced in fission reactors: the neutrons are sufficiently energetic that production of helium by (n,alpha) reactions in materials is a serious issue. The helium migrates to small very high pressure bubbles that break materials from the inside.
How? The lithium/beryllium "blanket" (i.e. thousand tons of molten metal in a maze of pipes) is inside the coils?
If you look at the ARC design, the blanket tank interposes between the coils and the plasma. There's also another neutron shield there (made of titanium dihydride) to further reduce the neutron dose on the magnets. Fun fact: the temperature of the salt in the blanket tank is > the decomposition temperature of TiH2, so in a serious accident large amounts of hydrogen gas could be produced.
There's a reason the ARC reactor is 20 meters tall and weighs as much as several WW2 US destroyers.
In your typical fusion reactor design, the blanket is not just inside the coils, it's inside the vacuum vessel (shielding the vacuum vessel from radiation damage and direct plasma heating too). This means any leak from the blanket is a leak into the fusion chamber itself, a criticality 1 issue for which redundancy is not possible.
"Results show: anticipated MTBF is hours/days (required is years), and MTTR is 3-4 months (required is days), and availability is very low < 5%"
I don't have a problem with talking about MTBF and replacing blankets etc but we are talking about research, not a reactor.
Also of note look at the MTBF of magnets and cryogenics in this system! (1.14years and 0.57 years)
What does seem like a real problem for them is the one you've brought up before: the limited supply of beryllium.
The problems above are not just a plasma instability problem, which has impeded progress. The interior walls of the fusion reactors are just pretty extreme environments, and the extremity is made worse by the fact that if you control plasma flow with magnetic fields, you trade the ability to control magnetic fields with dose -to-the-magnets-.
Achieving high magnetic fields also require high currents -> super conductors -> low temperatures (0.1-20 Kelvin).
Any thoughts on the real focus of the lab?
There is a statue of it in front of UW-Madison's Engineering Hall. It's a water display that, funnily, has not worked in many years.
[1] https://wci.llnl.gov/facilities/nif
Edit: However it is good to note that in comparison with other fusion methods, laser based methods relax materials constraints I listed above simply by spreading the energy/particle fluxes over larger surface areas.
If you built a giant fusion reactor based on NIF you could reduce DPA and temperature requirements, but it would fundamentally be a "shot" based reactor.