La for nuclear forensics*

Complete characterization of ²³⁵U fission and the decay of its fission fragments is important to develop a database for nuclear forensics applications. In pursuit of this goal, β- decay has been characterized for ¹⁴⁰La. ¹⁴⁰La has significance in nuclear forensics for dating nuclear events when its relative abundance to the parent ¹⁴⁰Ba is taken. Gamma spectra were collected with Gammasphere, currently located at ANL. The ¹⁴⁰La sample measured was created through neutron capture at the UMass Lowell reactor. Using calibrated spectra from¹⁴⁰La, previously observed levels have been confirmed and intensities measured, and new levels and transitions proposed are supported by coincidence spectroscopy. Preliminary results on the revised decay scheme and precision intensities will be presented.