TABLE OF CONTENTS The original Rutherford-scattering experiments demonstrated that each atom had a positively charged central core that we call its nucleus. However, even the original experiments of Geiger and Marsden showed deviations from the Rutherford formula at ?-particle energies above 25 MeV, and especially for scattering from nuclei of low- Z. Also, in the late 1920s, James Chadwick noticed serious discrepancies between expectations from Coulomb scattering and the elastic scattering of ?-particles on helium. The observed differences could not be attributed to expected quantum effects, first calculated by Neville Mott. All this indicated very clearly that there was more than just the Coulomb force involved in nuclear scattering.
Prior to the discovery of the neutron by Chadwick in 1932, it was thought that the nucleus contained protons and electrons, but it is now recognized that the nucleus consists of protons and neutrons collectively known as nucleons. Most of what we know about nuclei and the nuclear force has been obtained through decades of painstaking experimentation. In what follows, we will merely summarize the main features of the physics of the nucleus, and only occasionally present some of the crucial experimental underpinnings that led to the elucidation of nuclear phenomena.
The nucleus of any atom X, can be labeled uniquely by its electric charge or atomic number Z, and its total number of nucleons A, and is conventionally represented as A X Z . Alternatively,...
