Heavy Particle Groups From the Neutron Disintegrations of Nitrogen and Neon

Studies of the ₇N¹⁴(n,a)₅B¹¹ reaction by the method of Wilhelmy seem to indicate the emission of heavy particle groups from nitrogen as a result of resonance transmutation by fast neutrons from a Ra+Be source. The total energy of the alpha-particle plus recoil nuclei lies at 1.33, 1.64, 1.94, 2.15, 2.64, 2.98, 3.82, 4.14, and 4.48 Mev. The data are in good agreement with those of other experimenters and it appears unlikely that the maxima in the distribution curve are caused by statistical fluctuations, but are intimately connected with nuclear transformations. Neon yields three alpha-particle groups at 0.85, 1.05, and 1.68 Mev in the energy range 0.25-2.5 Mev by a similar study. It appears probable that the reaction ₁₀Ne²⁰(n,a)₈O¹⁷ is responsible for the 1.68-Mev group. The association of these groups with the intermediate nuclei Ne²¹ or Ne²³ is not unique as long as it is not clear which excited states of the end nuclei can occur, and as long as accurate mass values of all the nuclei involved in these reactions are not known. Hydrogen gave a smooth distribution curve, as was expected.