Hacker News Reader

Helion is working on a deuterium/helium-3 reactor, which if it works will produce only 6% of its energy as neutron radiation. YCombinator was an investor. They've run six reactors and are building a seventh now for a net power attempt in 2024.

There are also at least four companies working on proton-boron fusion, though all but one are very small. (TAE is the exception.)

Except they need a DD reactor to make the 3He to fuel the D3He reactor.

The plan is to do that in the same reactor.

D-3He. But 3He comes only from decaying tritium, so same problem.

At least D-3He might possibly be made to produce economically competitive power, if there were any 3He to burn in one. But it might be useful in space probes.

Whimsy. Is there a sequence of fusion technologies where the previous one lights the next one and if the current one goes out we're fucked?