I wish there was a good summary article of all the mainstream and alternative fusion approaches out there, like ITER, (SP-)ARC, General Fusion, Wendelstein 7X, etc.
I'm not the best one to explain what it is Helion is doing, but it's not p+B11 -> 4He.
In a sense, them patenting it so early is sort of a public good =)
And within those there are the variety of designs.
I hate to say it, but a tiny part of me doesn't discount the possibility of energy majors subtley killing small-scale fusion approaches and pushing internation-scale huge projects (i.e. ones unlikely to be delivered quickly).
[1] https://astronomy.stackexchange.com/questions/328/is-there-a...
After all, I'd be insanity to consume massive amounts of energy without accounting for its future costs.
Pretty much, but there are some that are kinda-sorta both (General Fusion's approach is "magneto-inertial"), and also a lot of variety within each bucket. Like, Zap Energy's approach is magnetic, but involves no external magnets, whereas developing the fancy magnets is a key operational challenge for CFS.
The general sense that I get (as a purely amateur observer but one who reads a fair bit about the various efforts) is that pretty much everyone thinks ITER will reach a decently high Q, but that it will take forever and be incredibly expensive, and that beyond that, of the people that think any of the startups have a chance (which seems to be a minority among fusion people but a decently big one), there's the most consensus around the potential of the high-field tokamak startups (so that's CFS/(SP)ARC and Tokamak Energy), because the physics is basically the same as with ITER, except facilitated by the much higher-strength fields allowed for by high-temperature-superconductor magnets; there are engineering challenges there still, but it seems like if the physics underlying ITER are sound and the magnets work (which has at this point been demonstrated as a stand-alone thing), the math all adds up. Stellarators (Wendelstein etc.) seem like the next-highest consensus: people seem to think the physics is sound, but it's less far along. Beyond that, other things seem to fall into one of: "the physics basis seems fine but the economics seem questionable" (probably most inertial approaches), "this has been considered at length and many believe this is physically impossible, but it'd be amazing if they're wrong" (TAE, arguably General Fusion, possibly also Helion), or "it'd be incredible if it works and physics doesn't forbid it but it's wildly novel and nobody really knows yet if it has legs" (things like Zap Energy's shear-stabilized Z-pinch plan).
The overarching tldr is that it seems like the approaches that the most people think will work also have some of the most significant operational challenges if they do (breeding tritium, dealing with high neutron flux, etc.), which is why anybody is bothering with the quirkier approaches: if they work, they will probably ultimately work better than the tokamaks do, but they might not work.