From https://astralcodexten.substack.com/p/open-thread-232: "Speaking of turning money into big positive impacts on the future, Sam Altman writes in to say he enjoyed the recent book review of The Future Of Fusion Energy, and that he predicts Helion (the fusion startup he’s a leading investor in) has a 85% chance of Q > 1 D-T fusion by 2024, and a 65% chance of Q > 1 D-He3 fusion by 2026."
Apr 14, 12:53pm: Will Helion achieve breakeven deuterium-tritium fusion by 2024? → Will Helion achieve breakeven deuterium-tritium fusion before 2024?
1,000
3.00Doing D-D fusion and claiming D-T extrapolated breakeven doesn't count, right?
In order to lower costs, many experimental machines are designed to run on test fuels of hydrogen or deuterium alone, leaving out the tritium. In this case, the term extrapolated breakeven is used to define the expected performance of the machine running on D-T fuel based on the performance when running on hydrogen or deuterium alone.
The records for extrapolated breakeven are slightly higher than the records for scientific breakeven. Both JET and JT-60 have reached values around 1.25 (see below for details) while running on D-D fuel. When running on D-T, only possible in JET, the maximum performance is about half the extrapolated value.
