Measurements of keV-Neutron Capture Cross Sections and Capture Gamma-Ray Spectra of ~(117,119)Sn

摘要

The neutron capture cross sections and the capture y-ray spectra of ~(117,119)Sn were measured in an energy region from 15 to 100keV and around 550 keV. A neutron time-of-flight method was adopted with a ns-pulsed neutron source based on the ~7Li(p,n)~7Be reaction and with a large anti-Compton Nal(Tl) spectrometer. A pulse-height weighting technique was applied to the observed capture y-ray pulse-height spectra to obtain the capture yields. Using the standard capture cross sections of ~(197)Au, the capture cross sections of ~(117,119)Sn were derived with the errors less than 5%. The capture y-ray spectra were obtained by unfolding the observed capture γ-ray pulse-height spectra. The present results for the capture cross sections are compared with the previous experimental values and the evaluated values of JENDL-3.3, and ENDF/B-VI.8 and VII.O.