Yield and Angular Distribution of the D-D Neutrons

The differential and total cross sections for neutron emission from the d-d reaction have been measured for deuteron energies between 0.5 and 3.7 Mev. A "thin" deuterium gas target and an energy insensitive neutron detector were used in the measurements. The yield in the center of mass coordinates was of the form N(θ)=K(1+Acos²θ+Bcos⁴θ+Ccos⁶θ); the total cross section was essentially constant (0.1 barn) for deuteron energies above 1 Mev. The coefficient A was found to be negative above 1.4 Mev and appreciable cos⁴θ was needed at all energies. Above 2.5 Mev, a cos⁶θ term was also appreciable. The angular distribution results can be understood qualitatively in terms of penetration of Coulomb and centrifugal barriers plus spin-orbit coupling.