Nuclear structure and depletion of nuclear isomers using electron linacs

Long-lived nuclear excited states (isomers) have proven important to understanding nuclear structure. With some isomers having half-lives of decades or longer, and intrinsic energy densities reaching 1012 J/kg, they have also been suggested for a wide range of applications. The ability to effectively transfer a population of nuclei from an isomer to shorter-lived levels will determine the feasibility of any applications. Here is described a first demonstration of the induced depletion of a population of the 438 year isomer of 108Ag to its 2.38 min ground state, using 6 MeV bremsstrahlung from a modified medical electron linac. The experiment suggests refinements to be implemented in the future and how a similar approach might be applied to study induced depletion of the 1200 year isomer of 166Ho.