Experimental design for an isomer depletion experiment on $^{\mathrm{108m}}$Ag via fast neutron reactions

The nuclide $^{108}$Ag is unstable with a ground-state half-life of 2.38 min, and primarily $\beta^{-}$ decays to $^{108}$Cd. Interestingly, the isomer $^{\mathrm{108m}}$Ag has a substantially longer half-life of 438 years due to its high spin (J $=$ 6) at modest energy (110 keV). This nuclide, with such a long isomeric lifetime and relatively short ground-state lifetime, is an excellent candidate for study as a potential medium for long-term energy storage. The key to extracting this energy is the ability to deplete part of the population held in the isomer state by exciting it to a higher-lying intermediate state that has a greater probability of transitioning toward the ground state. Isomer depletion for $^{\mathrm{108m}}$Ag has been successfully demonstrated at ARL using bremsstrahlung to excite intermediate states (AIP Conf. Prod. 1525, 586, 2013). The present experiment will investigate depletion of $^{\mathrm{108m}}$Ag via irradiation by fast neutrons at the NSWCCD accelerator facility -- the initial phase will use neutrons near 500 keV from the $^{7}$Li(p, n) reaction, so that only (n, n') reactions are expected. This poster will discuss the background, theory, and experimental design for this experiment, including the construction of a customized sample transport system and automated control utilizing LabVIEW.