MEASUREMENT OF THE keV NEUTRON CAPTURE CROSS SECTION OF Ni

The keV neutron capture cross section of Ni-62 was measured using an anti-Compton NaI(TI) spectrometers. Prompt discrete gamma-rays feeding from a neutron capture state of Ni-62 to low-lying excited states were observed. The Maxwellin-averaged cross section at 30 keV is derived to be 37.5 mb, which is 2.9 times larger than the value used in the calculation of nucleosynthetic yields of massive stars. The observation of discrete gamma-rays is crucial to unambiguously determine the small neutron cross section of Ni-62.