For decades, scientists have envisioned the possibility of storing energy in the form of nuclear excitations, resulting in specific nuclear configurations known as isomers. These unique metastable states have the ability to maintain their excited state for periods that range from several years to time spans exceeding the age of the Universe. However, despite numerous research efforts, achieving effective and practical control over isomer activation or depletion continues to be an unresolved challenge. This book delves into the world of...