Mass Defects and Nuclear Structure

Abstract

Light nuclei may be roughly described in terms of protons and neutrons held together by so far unknown binding forces. The binding energy E is obtained at expense of mass, the mass defect A mn being A m =,S/c. For a mass to be stable the mass defect increases as particles are added. We would expect a periodicity, similar to the periodicity in ionization potentials of elements of the periodic system, for the binding energies of nuclei. Starting from a pure proton and neutron picture as described by Bartlett,* we would expect that two protons and two neutrons could exist in the Is level and six more of each could exist in the Ip level. Thus we would expect the first break at He 4 and the second at 0 16. Mr. L. H. Horsley, at Kansas University, has shown that the regularities in the anomolous scattering of alpha-particles in-