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In recent years nuclear fission has gained renewed interest both from the nuclear energy community and in basic science. The first, represented by the OECD Nuclear Energy Agency, expressed the need for more accurate fission cross-section and fragment yield data for safety assessments of Generation IV reactor systems. In basic science modelling made much progress in describing the de-excitation mechanism of neutron-rich isotopes, e.g. produced in nuclear fission. Benchmarking the different models require a precise experimental data on prompt fission neutron and γ -ray emission, e.g. multiplicity, average energy per particle and total dissipated energy per fission, preferably as function of fission-fragment mass and total kinetic energy. A collaboration of scientists from JRC Geel (formerly known as JRC IRMM) and other institutes took the lead in establishing a dedicated measurement programme on prompt fission neutron and γ -ray characteristics, which has triggered even more measurement activities around the world. This contribution presents new advanced instrumentation and methodology we use to generate high-precision spectral data and will give a flavour of future data needs and opportunities. [ABSTRACT FROM AUTHOR]

In this paper, we present new spectroscopic information on Nb 94 from the Nb 93 (n t h ,2 γ) reaction. The intensities of the two-step gamma cascades in the compound nucleus Nb 94 to the final levels, with excitation energies below 400 keV, were derived from experimental spectra recorded at the PGAA facility of Centre for Energy Research (MTA EK), Budapest, Hungary. The intensities, energies of primary and secondary transitions of 216 energy-resolved cascades as well as intermediate cascade levels were determined. The part of the level scheme of Nb 94 was obtained from analyzing the intensity spectra of the strongest cascades. The results were compared to the existing data in the ENSDF database. We concluded that 27 primary transitions, 29 intermediate cascades levels as well as 183 secondary transitions can be recommended as new nuclear data. [ABSTRACT FROM AUTHOR]

This work provides new data about the level scheme of Mn 25 56 studied by the Mn 25 55 (n t h ,2 γ) reaction. The spectroscopic information were collected using the gamma-gamma coincidence spectrometer at the Technische Universität München, Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany. The intensities, energies of primary and secondary transitions of 71 energy-resolved cascades, as well as intermediate cascade levels were determined. The updated level scheme of Mn 25 56 was obtained from analyzing the intensity spectra of the strongest cascades. The comparison with the existing data in the ENSDF database shows that 23 primary transitions, 24 intermediate cascades levels as well as 32 secondary transitions determinated in this work can be recommended as new nuclear data. [ABSTRACT FROM AUTHOR]