Conveniently, pure deuterium fusion (D-D) is easier than D-He3 fusion, and the output of D-D fusion is half He3, and half tritium which decays to He3 with a 12-

Conveniently, pure deuterium fusion (D-D) is easier than D-He3 fusion, and the output of D-D fusion is half He3, and half tritium which decays to He3 with a 12-year half-life. So if we can get net power from He3, we can make He3 from deuterium and generate energy in the process. D-D fusion does produce neutrons but they're much lower energy than D-T neutrons. Fusion startup Helion is working on a hybrid D-D/D-He3 reactor, saying the combination will produce only 6% of its energy as neutron radiation, low enough so they can do direct conversion. They've built half a dozen reactors, and now they're working on a seventh that they'll use for a net power attempt around 2025. They recently had a fundraising round led by Sam Altman, and raised $500M with another $1.7 billion of commitments based on milestones. https://techcrunch.com/2021/11/05/helion-series-e/ https://techcrunch.com/2021/11/05/helion-series-e/