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 ^{147,148,149,150,152,154}Sm 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.

KEYWORDS:

• neutrons
• keV range 10–100
• keV range 100–1000
• neutron capture
• cross sections
• gamma-ray spectra
• experimental data
• samarium 147
• samarium 148
• samarium 149
• samarium 150
• samarium 152
• samarium 154
• gold 197
• anti-Compton NaI(Tl) gamma-ray spectrometer
• time-of-flight method
• pulse-height weighting technique