Study on the Excitation and Deexcitation Paths of ¹⁷⁸Hf Isomer

Isomer with long lifetime and high excitation energy is of great significance in the fields of national strategic security and energy storage. Mastering the method of inducing isomer to decay is the key technology. However, this technology has got into trouble in recent years. For mastering the method of inducing isomer to decay, it is beneficial to start the research on the formation, excitation and de-excitation mechanism of isomer from the view of atomic nucleus structure. In this work, we used a white light neutron beam to bombard the Hf target in terms of experimental technology, and innovatively established a triple coincidence measurement system consisting of a barium fluoride detector array GTAF-Ⅱ for full energy measurement, a high-purity germanium detector for characteristic γ-ray measurement, and a white light neutron time-of-flight measurement. Through the analysis of experimental data, we found the sign of the ¹⁷⁸Hf isomeric state exciting to the transition level and releasing rapidly.