Comment by gpm
4 months ago
With regards to scaling, I think there are two components:
Does the physics change as they scale up the field strength? No one is really going to know until they try (unless we get a lot better at simulating plasma real fast). If not, they lost a bet, but they lost it honestly and as far as I can tell (not a physicist) it was a reasonably good bet to make.
Can they physically build the bigger magnets they need fast enough to meet their timelines (and everything else. I understand they are currently bottlenecked on capacitors)? Apart from normal "startups are overly optimistic" issues I don't see any reason to think that they shouldn't be able to reliably predict how fast they can scale magnet size, or be limited to a linear rate. While they are big magnets, it's not exactly new physics.
I'm not sure I'd say they are "probably going to be viable" anytime soon either. I think they have a good chance, but "probably" as in ">50%" is probably pushing it. (Also depends on where you put the goalposts of course)
FWIW I believe that 2018 report was for a high gain low pulse rate plan that Helion rejected, and they are aiming for substantially lower strength magnets as a result. I can't find anything more than rumors to confirm that though.
Just to be clear: I'm not accusing Helion of being dishonest or even fraudulent.
It's just that from everything I know about the project, they still have a long way to go, and there are a lot of milestones to hit that are just pipe dreams for now (actually fusing He3, breeding it, net-gain energy extraction, ...).
I would expect progress to slow down significantly as the scale of prototypes and their complexity increases (like what happens for basically every engineering project ever)-- but progress is already slow/behind schedule to begin with...