The level structure of 140La and 142Pr from the (n, γ) reaction

A study of the 139La(n, γ)140La and 141Pr(n, γ)142Pr reactions using a Ge(Li) spectrometer has given neutron separation energies of 5165±5 and 5842±5 keV, respectively. Both nuclei have reasonably simple spectra for doubly-odd species due to the 83 neutron configuration. About 40 high-energy transitions were found in each case, and for 140La the reduced dipole width to f-wave neutron states appears wider than to p-wave states. The low-energy …