The normal modes of the nucleus as revealed by electromagnetic coincidence experiments

The recent development of high duty factor electron accelerators has permitted the application of a variety of electromagnetic coincidence techniques to the study of the normal modes of the nucleus. The photon tagging technique, long used to monochromate bremsstrahlung, has been rejuvenated by the orders of magnitude increase in available flux that has come with high duty factor electron beams. The electron scattering coincidence technique, heretofore limited to reactions such as quasi-elastic (e,e'p) for which there are strong angular correlations between the reaction products, can now be applied to a much broader range of nuclear structure problems. In this paper the authors discuss briefly these two techniques, and give examples from recent experimental results that demonstrate their power and potential