Читать книгу Essentials of Nuclear Medicine Physics, Instrumentation, and Radiation Biology - Rachel A. Powsner - Страница 34

Following alpha and beta decay and electron capture, the nucleus has a more favorable physical configuration of nucleons but usually contains an excess of energy. The nucleus is said to be in an excited state when the energy of the nucleus is greater than its resting level. This excess energy is shed by isomeric transition. This may occur by either or both of two competing reactions: gamma emission or internal conversion. Most isomeric transitions occur as a combination of these two reactions.