The article mentions Helion. Those guys were supposed to have their Polaris demo machine running by now. But they've become very quiet about that. Press releases about it in 2024, but not much in 2025.

Polaris is supposed to pass theoretical breakeven, and maybe even technical breakeven - more electrical power out than they put in. That would be a huge event.

Polaris has been operating at low power already. They have recently installed shielding in the walls to allow higher power operation.

There seems to be a fair bit of progress notes from them. They aren't obligated to tell us anything, of course.