Helion is the only fusion startup I know of that is not obviously a scam. They count on D-D side reactions for neutrons to use breeding tritium, which decays o

Helion is the only fusion startup I know of that is not obviously a scam. They count on D-D side reactions for neutrons to use breeding tritium, which decays over decades to the 3He they need. I don't see how that could produce enough. If not, their thing might still end up usable to power outer solar system space probes, using 3He decayed from the usual CANDU-produced tritium. The Princeton FRC design is intended for spacecraft propulsion. I don't know if it is more or less practical.