Final Task Report on NRF Measurements of Photon Scattering Resonances in Plutonium at the High Voltage Research Laboratory of MIT

Conclusions of this report are that there are 13 new transitions associated with NRF states in {sup 239}Pu that have been discovered. These resonances are between 2- and 2.5-MeV relative to the ground state in {sup 239}Pu. The strengths of most these resonances are between 15 and 20 eV b. This approximately is the strength required for using the transmission detection method for NRF [Pruet et al J. Appl. Phys. 99 12310 (2006)] for six-sigma alarm confidence levels. Future measurements on {sup 239}Pu at higher photon energies are necessary to probe for NRF strengths at higher energies. Such resonances may be more advantageous to the NRF technique with FINDER if they are stronger or if the mean free path of these energetic photons is longer