Continuing the discussion here as it is off topic for the ZAP- thread.
Original post here:
viewtopic.php?p=134167#p134167
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).
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.
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.
Giorgio wrote: ↑Fri Nov 04, 2022 8:14 am
Even pulsed machine have a steady state.That is the state when the value of all the internal variables reach an equilibrium due to the continuous energy fluxes from the sequence of pulses. Think of it like the "warm up" phase of an internal combustion engine. The difference in behavior from the cold engine to the steady state (equilibrium of all Variables) can be quite big, and the same apply to Helion and ZAP.
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.
The good news is that with a higher pulse rate in Polaris, they can get to that ten-thousands shot within 3 hours. Then they can ramp the machine up and down every 3 hours for months and learn how that works. For the power plant design, they likely have to do it all over again though, because those machines will be slightly bigger and have slightly different parameters than Polaris. But then for those power plants it will only take some 17 minutes. The same is true for ZAP with their power plant design (both theirs and Helion's use the same pulse rate).
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.
Again, interesting times we live in.