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 $N\left(\theta \right)=K(1+A{cos}^2\theta +B{cos}^4\theta +C{cos}^6\theta )$; 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 ${cos}^4\theta$ was needed at all energies. Above 2.5 Mev, a ${cos}^6\theta$ 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.