Search for Nuclear Isotopes for Use in a Nuclear Battery

Performance of a radioisotopic thermoelectric generator for a human-portable energy source is discussed. The design ofthermoelectricgeneratorsis notconsidered. Instead desirablecharacteristicsoftheradioisotopeareused to search for reasonable candidates with a half-life measured in weeks and generating radiation that could easily be shielded. Because radioisotopes with short half-lives would have limited shelf-lives, a search was undertaken to discover if isomers with different decay paths existed with characteristics that would lead to a useful energy generator design. The results indicate several interesting cases for energy storage in radioactive isotopes. Two of the most interesting cases uncovered were 121 Te and 254 Es. However, intermediate levels that could be used to connect the various nuclear energy levels are not currently known. Measurements of transition rates that can be stimulated between the desired levels are also needed to determine the practicality of this concept. Such research is now possible using the intense gamma beam that can be produced using free-electron laser light backscattered from relativistic electrons.