Neutron capture cross section and capture -ray spectra of Ba in the keV-neutron energy region

Katabuchi, Tatsuya*; Yanagida, Shotaro*; Terada, Kazushi; Iwamoto, Nobuyuki  ; Igashira, Masayuki*

Ba has the smallest neutron capture cross section among the stable Ba isotopes. The neutron capture reaction of Ba is dominated by resolved resonances in the astrophysically relevant energy region. Thus, reliable experimental data of the capture cross section are necessary. In the present work, we measured the neutron capture cross section of Ba in the energy region from 15 to 100 keV by the time-of-flight method at the Tokyo Institute of Technology. The capture cross sections were obtained from the pulse height spectra by the pulse-height weighting technique. A comparison of the present results with previous experimental data and evaluated data was made. We also derived -ray spectra by unfolding the pulse height spectra. It was revealed that the shape of -ray spectra strongly depends on neutron energy.