Nuclear Isomer High Energy Density Storage System for Army Applications

Nuclear isomers store energy in metastable nuclear states at up to a million-fold greater density than high-energy chemical systems. A particular isomer of Hafnium, Hf-178m2, stores 1.3 gigajoules of energy per gram of isomer. It has an unusually longhalf-life of 31 years. It releases its 2.45 MeV of stored energy per nuclei as a cascade of gamma photons. The truly unique aspect of this isomer, first shown in 1998, is that it can be triggered to release the stored energy at an accelerated rate usinglow energy photons. A quantum energy gain of at least 60 is achieved, raising the possibility of using a portion of the released energy to self-sustain a continuing chain reaction at either a controlled or unlimited rate of release. The controlledaccelerated release of this stored energy with the application of high energy density storage systems for future Army systems is the subject of this research. The concept design parameters will be defined through a combination of calculations, existingempirical data, and specific experiments on the Hf-178m2 isomer for verification. A break-even experiment will be defined, and a master program plan will be developed to accomplish the technology development in a phased demonstration approach.Nuclearisomer technology will allow the development of energy storage devices with far greater energy densities than conventional devices while also being far safer than other nuclear devices. Nuclear isomers also have potential applications in the areas oflethality against biological weapon threats, advanced space propulsion, oncology treatments, and gamma ray lasers.