Sorry for late reply, I had to take urgently a plane back to Europe to solve some local made mess and I didn't have any time to connect.
Skipjack wrote: ↑Sat Nov 05, 2022 1:28 am
Giorgio wrote: ↑Fri Nov 04, 2022 8:14 am
Their blanket diameter is 3 meter, so also the breeding and separation of the newly bred Tritium is not a concern as we have plenty of literature on both these points since the 90's.
3 meters is the total diameter of their machine (excluding that new outer shielding construction). So the liquid blanket is maybe 1.25 meters in thickness. Once possible concern could be evaporation of that liquid blanket material and subsequent contamination of the plasma. But then I guess it is not that bad, since they can evacuate the chamber after every shot (so does Helion).
Yes of course, is a torus, so a diameter of 3 meter will equal to a thickness of 1.2 m to 1.3 m where they have the where there
I remember clearly that Zap disclosed several times that the torus diameter was calculated using a Monte Carlo N-particle code derived from previous experiments and that the thickness was set to produce a tritium breeding ratio of 1.1
I am not sure I ever read anything about Helion blanket thickness needs, I tried to remember if they disclosed it in the past but nothing come to my mind.
Skipjack wrote: ↑Sat Nov 05, 2022 1:28 am
Giorgio wrote: ↑Fri Nov 04, 2022 8:14 am
Different will be the situation for Helion that will use a solid blanket where the Tritium migration processes is dependent from quite a large number of variables. There is lot of literature with mixed results as small changes in operating parameters can swing conversion efficiency quite a lot.
That is my concern for them.
Helion does not use a Lithium blanket at all... At least they don't plan to do so in the first power plant designs. They will just rely on the He3 and T from D-D reactions. No Lithium blanket for extra Tritium breeding.
Well, this is a news to me because they do have a Li blanket to capture the low energy "n", it is part of the patent on the fuel cycle. If they plan not to use it in the start than it is not a problem, but it will effect overall efficiencies.
Maybe they consider it not essential now, but still those "n" need to be captured somewhere.
Skipjack wrote: ↑Sat Nov 05, 2022 1:28 am
Giorgio wrote: ↑Fri Nov 04, 2022 8:14 am
I am happy that I am not he only one that sees it as an issue, and I hope we are all wrong about it, but I still lack the data to change idea on this point.
The disbelief of people outside of the company is not really an issue for Helion's design. Personally, I do not understand all that skepticism, neither does David Kirtley. It is a very simple principle. The only problem was the electronics for controls but that was solved for Helion by others. E.g., some components were originally developed for regenerative braking in electric cars. I think some were also developed for wind turbines, but I might be remembering this wrong.
It's not real disbelief, is more a concern. I agree that there is lot of pieces of the puzzle out there that has been solved by other, but still the puzzle has never been put together in one piece, and we all know that in this sector the devil is indeed in the details..
Skipjack wrote: ↑Sat Nov 05, 2022 1:28 am
If I am not misinterpreting what you are saying, then sort of agree with that. Helion has gained a lot of experience with the issue of "the first shot is different from the tenth and that one is different from the 10 thousands shot" (paraphrasing David Kirtley here). The machines have a sort of a "warm up phase" after initial commission and there will likely also be one during a sequence of shots.
Absolutely, I think it was right to make one of their main goals to understand how their machine will actually need to be "conditioned" before and after delivery to the customer. But I think that to get a real knowledge they will need to wait to get real data when they start to actually use the machine as a power generator. This of course is true for both.
Skipjack wrote: ↑Sat Nov 05, 2022 1:28 am
Giorgio wrote: ↑Fri Nov 04, 2022 8:14 am
In Helion all the major components are inside the machine and are participant/subjected to the changes of the system as it evolves.
Not sure you can say it like that. Helion's components are all outside the first wall or located pretty far away from the interaction chamber. That is actually one of the beauties about Helions design. That said, ZAP's design has less components and is overall simpler.
If you speak about "first wall" than I agree with you, but Helion machine is still a closed chamber, so the reaction results will effect the inside of the chamber even if components are not in the immediate surrounding of the "first wall".
In this point, if they actually plan not to use a Li blanket, than they can for sure remove lot of variables and headaches in the start up phase, but those low energy "n" must go somewhere, so I am afraid that they might just skip an immediate problem to face a long term problem later on. But I do not have enough data to sustain this claim, it is just my personal feeling so take it with the due value.