protoni11B

Protoni11B refers to the nuclear fusion reaction between a proton and boron-11, producing three alpha particles. It is commonly described as proton–boron fusion or p–11B fusion and is sometimes highlighted as an aneutronic fusion candidate because the main reaction channel does not produce neutrons.

The primary reaction can be written as p + 11B → 3 4He. The Q-value for this process is about +8.7 MeV, meaning the reaction releases energy in the form of the kinetic energy of the three alpha particles. The resulting alpha particles carry the bulk of this energy, distributed according to reaction kinematics.

Feasibility and challenges: The fusion cross-section for p–11B is highly energy dependent and, at low energies, is relatively small, requiring substantial proton energies and high plasma density or particle-accelerator beams to achieve meaningful reaction rates. While the absence of primary neutron production is attractive for radiation shielding and waste considerations, the reaction can still generate secondary gamma rays through alternative channels, and the energetic alpha particles pose material and engineering challenges for containment and heat handling. In addition, achieving a net energy gain is difficult because bremsstrahlung losses in hot plasmas and the overall energy balance tend to be unfavorable compared with other fusion approaches. As a result, while p–11B fusion remains of interest for clean energy concepts and certain diagnostic applications, it has not yet demonstrated practical, net-energy production in an engineering-scale reactor.

In summary, protonu11B describes the proton–boron-11 fusion reaction that yields three alpha particles with a high positive Q-value, and it is studied as a potential clean energy path, though practical realization remains an area of ongoing research.