Revisiting Fusion in D-${}^{3}$He Plasmas With Spin-Polarized Fuel

Spin-polarized fuel (SPF) is recognized for enhancing fusion reactivity, but it could provide other advantages particularly relevant to advanced fusion fuels. In this work, we calculate how SPF in D-${}^3$He plasmas affects not only D-${}^3$He fusion reactions but D-D fusion and subsequent secondary reactions. By incorporating multiple effects, we show how, under optimistic assumptions, the fusion power relative to unpolarized D-${}^3$He fusion power could increase by more than a factor of three by polarizing the deuterium and helium-3. Such an increase may improve the feasibility of fusion concepts using D-${}^3$He fuel. We perform a case study with a hypothetical pulsed magneto-inertial fusion device using polarized D-${}^3$He fuel, showing how the net electric power could increase by almost an order of magnitude. We also consider the potential of SPF to provide a path to fully aneutronic fusion. This work is a new look at how SPF could improve the feasibility of fusion concepts using advanced fuels.