Measurement of keV-neutron capture cross sections and capture gamma-ray spectra of Nd-143,Nd-145.146

The neutron capture cross sections and capture gamma-ray spectra of Nd-143, Nd-145,Nd-146 were measured in the neu tron energy region of 10 to 90 keV a nd at 550 keV. A neutron time-of-flight method was adopted with a 1.5-ns pu lsed neutron source by the Li-7(p, n)Be-7 reaction and with a large anti-Co mpton NaI(T1) gamma-ray spectrometer. A pulse-height weighting technique wa s applied to observed capture gamma-ray pulse-height spectra to derive capt ure yields. The capture cross sections were obtained with the error of abou t 5% by using the standard capture cross sections of (197) Au. The evaluate d values of JENDL-3.2 and previous measurements were compared with the pres ent results. The capture gamma-ray spectra were obtained by unfolding the o bserved capture gamma-ray pulse-height spectra. An anomalous shoulder was o bserved around 2 MeV in the gamma-ray spectra of Nd-145.146, and the energy position of the shoulder was consistent with the systematics obtained in o ur previous work.