Nuclear physics is a branch of physics that looks at the constituents and interactions of atomic nuclei. Applications of nuclear physics include nuclear power generation and nuclear weapons technology. Nuclear physics also provides applications in nuclear medicine, magnetic resonance imaging, ion implantation and radio carbon dating. Particle physics is often associated with nuclear physics.
Historically, nuclear physics and atomic physics were distinct disciplines. In 1896 Henri Becquerel discovered radioactivity. At the beginning of the 20th century, J.J. Thomson founded the plum pudding model. This model displayed the atom as a large positively charged ball with small negatively charged electrons embedded inside of it.
After the plum pudding model’s discovery, scientists found three types of radiation emanating from atoms, alpha, beta and gamma radiation. It was found that the beta decay spectrum was continuous rather than discrete. Electrons were being ejected from the atom with a range of energies rather than a discrete amount of energies that was observed in gamma and alpha decays. This indicated that energy was not conserved in these decays.
Modern nuclear physics looks at nuclei under extreme conditions such as high spin and excitation energy. Experiments on these nuclei’s can create artificially induced fusion and nucleon transfer reactions. These artificially induced reactions are very useful modern technologies.