Uncollided Neutron Fluences in a Mirror-Like Machine (MFTF-B) with Polarized DT Plasmas

Abstract

According to Kulsrud et al.1, polarized DT plasmas could be interesting for a fusion reactor because polarization of deuteron and triton spins would influence both the fusion rate and the angular distribution of the fusion products (14 MeV neutrons and 3.5 MeV alpha particles). In particular, with parallel polarization (in which all the deuteron and triton spins are parallel to the confining magnetic field ) the fusion cross section would increase by a factor 1.5 and the angular distribution would be described by (1/2)sin2α (where α is the angle comprised between and the line of flight of either fusion product), which is equivalent to saying that alpha particles and neutrons would be emitted preferentially in a direction perpendicular to . On the contrary, with transverse polarization (in which all the deuteron spins are normal to ) the fusion cross section would remain unaltered and the angular distribution would vary as (1 + 3 cos2α)/2, which means that in this case the fusion products would be emitted preferentially along the direction of .