Measurement of ke V-Neutron Capture Cross Sections and Capture Gamma-Ray Spectra of ^{147,148,149,150,152,154}Sm

Abstract

The neutron capture cross sections and capture γ-ray spectra of 147,148,149,150,152,154Sm were measured in the neutron energy region of 10 to 90 keV and at 550 keV. A neutron time-of-flight method was adopted with a 1.5-ns pulsed neutron source by the 7Li(p, n)7Be reaction and with a large anti-Compton NaI(Tl) γ-ray spectrometer. A pulse-height weighting technique was applied to observed capture γ-ray pulse-height spectra to derive capture yields. The capture cross sections were obtained with the error of about 5% by using the standard capture cross sections of 197Au. The present results were compared with the evaluated values of JENDL-3.2 and previous measurements. The capture γ-ray spectra were obtained by unfolding the observed capture γ-ray pulse-height spectra. An anomalous shoulder was clearly observed around 3 MeV in the γ-ray spectra of 150,152,154Sm, and the energy position of the shoulder was consistent with the systematics obtained in our previous work.