Low energy collisions of polarized light nuclei: physics and applications

We discuss the implications of strong polarization effects which manifest in collisions of light nuclei at low energies (≤ 1 MeV). We establish the spin structure of the threshold matrix elements of the processes d + 3He → p + 4He and d + 3H → n + 4He, which are considered as the most promising reactions for energy production in fusion reactors. The possible increase of the cross section in collision of polarised particles may have important consequences for reactor physics and muon-catalyzed fusion. The effects of polarization in the processes p+p → d+e+ +ν and n+p → d+γ may be very important in astrophysics applications, in particular for models on neutron stars and for nucleosynthesis in early universe. This is due to the possible existence of very strong magnetic fields which can polarise protons, neutrons and deuterons. (author)