Prompt gamma rays of lanthanum and praseodymium produced by inelastic scattering of fission neutrons

Abstract Emission of prompt gamma rays in lanthanum and praseodymium nuclei triggered by (n,n’γ) inelastic scattering reactions of fission neutrons was investigated with the instrument FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) at Heinz Maier-Leibnitz Zentrum (MLZ). We identified 125 gamma lines (54 for lanthanum and 71 for praseodymium), for which we give the relative intensities and production cross sections. Presence of oxygen and chlorine in the samples was exploited to verify previous measurements. Our results are consistent with available literature data but also enhance it as we detect new lines and recognize a few false assignments. In addition, for a counting time of 12 h we estimated the detection limits of lanthanum and praseodymium as 0.6 and 0.4 mg, respectively.