γ spectroscopy experiments relevant for nuclear waste transmutation

γ-spectroscopy is an important tool also for nuclear waste transmutation studies. An experiment has been performed at ILL Grenoble to measure 241Am and 242gsAm thermal capture cross sections that play a major role for the transmutation of 241Am in a high thermal neutron flux, coupling γ-spectroscopy with mass spectrometry methods. σc(242gsAm), for which the three main evaluation data libraries were giving very different values, has been measured to be 280±40 barns. That confirms the low cross section value making possible the 241Am transmutation by thermal neutrons. In the MINI-INCA project, we plan to widen the measurement to other minor actinides of interest using γ and α-spectroscopy of neutron irradiated samples for thermal and epi-thermal fluxes up to 2.1015 n/s/cm2.