Nuclear Isomer Energy Storage System

This proposal addresses the use of nuclear isomers as energy-storage/energy-delivery systems for defense and civilian applications. Nuclear isomers are long-lived (>1ns) excited states of nuclei that release their excess energy by electromagnetic decay.The nuclear state energy densities stored in some isomers are 103 to 104 times higher per unit mass (¿¿109 J/g) than for chemical systems. This leads directly to the possible application of isomers as batteries to provide useful energy in space orbattlefield operations or as flash discharge devices to provide an intense pulse of penetrating electromagnetic radiation. The utility of isomers for energy storage depends on their half-life (T1/2¿¿1 year or greater) and net energy gain, and on theability both to produce them and to stimulate the release of their stored energy. This Phase II research project will 1) investigate a novel method that could provide > 1016 nuclei of the isomer 178m2Hf in a highly concentrated form for future triggeringstudies, and 2) investigate methods to produce and trigger other isomers that are candidates for high-density energy storage. Innovative triggering concepts using both neutrons and fast-pulsed x-ray sources will be studied both theoretically andexperimentally.Isomers have the potential to be alterntive to batteries, fuel cells, and capacitors. In addition, there are many space-based applications, including sommmunications and power sources for interplanetary travel and future space stations. Ifflash gamma ray devices can be configured to release highly penetrating IEMP, their use in ordnance could reduce the size and weight, resulting in more mobile weapons systems.