Neutron capture cross sections of curium isotopes measured with ANNRI at J-PARC

The neutron capture cross sections of ²⁴⁴Cm and ²⁴⁶Cm were measured for the neutron energy range of 1-1000 eV via the neutron time-of-flight method with Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) at Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). The world's most intense neutron pulses from the Japan Spallation Neutron Source (JSNS) enable the accurate measurement of neutron capture cross sections. Besides, single-bunched neutron pulses allow the analysis in a higher neutron energy region than the previous measurement at ANNRI. The resonance analyses were performed up to 1000 eV by using a resonance shape analysis code REFIT. The spectra of prompt gamma-rays from neutron capture reactions of ²⁴⁴Cm and ²⁴⁶Cm were also obtained, and 43 and 10 prompt gamma-ray peaks from ²⁴⁴Cm (n,γ) and ²⁴⁶Cm (n,γ) reactions were newly observed, respectively. (author)