I've been reading all I can google about fusion for several months now, both to write better spaceship drives and to better understand the fusion start-ups who promise to bring this planet-saving technology online far sooner than the government's (deliberately?) time- and money-wasting approaches. I'm patrticularly excited by General Physics' steampunk approach--they gobsmack plasma to fusion!--and their liquid lead-lithium wall that soaks up the high-energy neutrons produced by deuterium-tritium before they can damage the reactor vessel. By Lawrenceville Plasma Physics dense plasma focus and aneutronic proton-boron 11 cycle--if they can deliver on 5Mw reactors that will fit in a pickup truck, for $ a few hundred k, the third world can leapfrog fossil fuels. And Helion Energy's strategy--if you can't get He3, make it--is also brilliant. And that's what my question is about. Helion plans to fuse deuterium-deuterium (D-D) to make He3 and tritium (T), then somehow stop the reaction before the T fuses with D to make a bunch of those pesky 14.1 MeV neutrons. Burn the He3 with D to produce power (I think they'll need two reactors, a breeder to produce fuel and another to burn it, but they don't say so that I've read yet), and store the T until it decays into He3. But preventing the D-T fusing seems difficult, given that D-T ignites at ~1/3 the temperature required by D-D. Might D-p be easier? There are other low-Lawson criteria (if I understand the term--low tripple product required? Easy to ignite-) fusion fuels, easy enough to ignite that they fuse in protostars and brown dwarfs: protons with both isotopes of lithium, others--and D-p, deuterium-proton. D-p starts at only 10^6K, doesn't get much hotter than that--is that a problem? produces an He3 and an x-ray (I think, and maybe a neutrino?), and that's about all I can find about it online. Why does there seem to be so little interest in this reaction? Why wouldn't this be a good fusion fuel for power plants? Low energy produced? Anyone know how many MeV, total reaction chain? Or like the p-p that fires smaller stars, is D-p's reaction rate too slow? And even if it's a low-energy reaction, could it be sped up enough (if a slow reaction rate is the problem) to use it to make He3?