Built, physically operational reactors that operate as close to Q=1 as they can, with all the diagnostics included.

The diagnostics are very important, as plasma instabilities have been, and continue to be, the critical issue preventing anything useful coming out of our decades of fusion reactor design. All these companies are sharing data on overcoming plasma instability issues, with multiple geometries aimed at evaluating how plasma responds to different inputs in different environments. We're all trying to understand how to control and compress something far too hot to physically touch.

@naturalgasbad@lemmy.ca scaling fusion isn't a trivial problem, and saying it like it is indicates a lack of background knowledge. This isn't a competition between companies (no matter what our CEOs suggest), as we in industry quietly all agree that any of us that cracks this unchains humanity from the solar system. Because government funding has unfortunately sucked so much ass, we're sort of using private money to get the basic research done. We'd be so much farther ahead otherwise.