MEASUREMENTS OF keV-NEUTRON CAPTURE GAMMA-RAY SPECTRA OF Fe AND Ni
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology
2-12-1 O-okayama, Meguro-ku, Tokyo 152, Japan
We have measured capture gamma-ray spectra of Fe and Ni at several neutron energies between 10 and 600 keV with an anti-Compton NaI(Tl) detector, employing a time-of-flight technique. Observed pulse-height spectra were unfolded using a response matrix of the detector in order to obtain capture gamma-ray spectra. Strong transitions from capture states to low-lying excited states of the residual nuclei were observed in both gamma-ray spectra. These spectra were compared with statistical model calculations. The calculation underestimates the strong transitions, but as a whole it reproduces fairly well the observed spectra at neutron energies of several hundreds keV.
KEYWORDS: capture gamma-ray spectrum, keV neutron, Fe, Ni, statistical model calculation