Cross Section Measurement of 237Np(n,γ) at J-PARC/MLF/ANNRI

The cross section of the 237Np(n,γ) reaction has been measured at the Japan Proton Accelerator Research Complex (J-PARC). The NaI(Tl) spectrometer installed in the accurate neutron-nucleus reaction measurement instrument (ANNRI) was used for the measurement. The relative cross section was obtained using the neutron spectrum measured by the 10B(n,α1) reaction. The absolute value of the cross section was deduced by normalizing the relative cross section to the evaluated value in JENDL-4.0 at the first resonance.