Speaker
Description
Excitation of long-lived states in bromine nuclei using a table-top laser-plasma accelerator providing pulsed (<100 fs) electron beams provided a sensitive probe of gamma strength and level densities in the nuclear quasicontinuum, and may indicate angular momentum coupling through electron-nuclear interactions. Solid-density LaBr$_{3}$ active targets absorb real and virtual photons up to 35 ± 2.5 MeV and de-excite through gamma cascade into different states. A factor of 4.354 ± 0.932 enhancement of the $^{80m}$Br/$^{80g}$Br isomeric ratio was observed following electron irradiation, as compared to bremsstrahlung. Additional angular momentum transfer could possibly occur through nuclear-plasma or electron-nuclear interactions enabled by the ultra-short electron beam. Extension of this enhanced angular momentum coupling into heavy nuclei is being explored as a potential method for production of $^{225}$Ac, an isotope of strong interest to the radiopharmaceutical and research communities, through the enhanced alpha-decay of $^{229}$Th.
