Am neutron capture cross section measurement using the NaI(Tl) spectrometer of the ANNRI beamline of J-PARC

Rovira Leveroni, G.   ; Kimura, Atsushi   ; Nakamura, Shoji  ; Endo, Shunsuke   ; Iwamoto, Osamu  ; Iwamoto, Nobuyuki  ; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*

The neutron capture cross-section of Am was measured from 10 meV to about 1 MeV using the NaI(Tl) spectrometer of the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Materials and Life Science (MLF) facility of the Japan Proton Accelerator Research Complex (J-PARC). The total energy detection principle was applied in conjunction with the pulse-height weighting technique to derive the neutron capture yield. The present cross-section results were normalized using a Au sample measurement by applying the saturated resonance method. The thermal cross section was measured to be 708 22 b, in agreement within uncertainties to the present evaluation in JENDL-5 of 709 b. Moreover, the results of a shape resonance analysis of the resolved resonance region are also provided in the present dissertation.