DHe3

DHe3 refers to the fusion reactions between deuterium (D) and helium-3 (He-3). The most often cited channel is D + He-3 → He-4 + gamma, a process that releases roughly 18 MeV of energy primarily carried by a high-energy gamma ray. There is also a competing branch, D + He-3 → p + He-4, which produces a proton and helium-4. Because these reactions produce few neutrons, D-He-3 fusion is frequently described as having lower neutron activation and simpler shielding requirements compared with deuterium-tritium (D-T) fusion, though the gamma output means it is not entirely neutron-free.

Realization and challenges: Achieving practical D-He-3 fusion requires very high temperatures and strong confinement due to relatively small fusion cross-sections at accessible conditions. In addition, helium-3 is scarce on Earth and expensive, complicating fuel supply for large-scale experiments. These factors have limited the development of D-He-3 fusion relative to D-T and D-D approaches, though it remains an area of theoretical and experimental interest.

Research status and potential: D-He-3 fusion has been investigated in both magnetic confinement and inertial confinement contexts, focusing on cross-section measurements, energy spectra of fusion products, and the implications for reactor design. The appeal lies in the potential for high energy output with reduced neutron production, which could simplify shielding and reduce long-term radioactive activation. Practical deployment remains speculative, constrained by fuel availability, ignition requirements, and the need for advanced confinement technologies. Some proposals discuss space propulsion or specialized aneutronic fusion concepts, where the fuel’s characteristics could be advantageous.