Measurements of the Neutron Total Cross-Sections of Tantalum by Using Pulsed Neutrons Based on an Electron Linac

Abstract

The neutron total cross-sections of tantalum (181Ta) were measured in the neutron energy region from 0.01 eV to 100 eV by using the time-of-flight method at the Pohang Neutron Facility, which

consists of an electron linac, a water-cooled tantalum target with a water moderator, and a 12-m- long time-of-flight path. A 6Li-ZnS(Ag) scintillator with a diameter of 12.5 cm and a thickness of

1.6 cm was used as a neutron detector, and a natural tantalum metal plate, 10 × 10 cm2 in area by 0.45 mm in thickness, was used for the neutron transmission measurement. The background level was determined by using a notch-filter of Co, In, and Cd sheets. The present measurement was compared with the previous ones and the evaluated data in ENDF/B-VI.8. The resonance parameters of 181Ta isotope were obtained from the transmission ratio by using the SAMMY code, which utilizes both Doppler and resolution broadening effects and Bayes’ generalized least squares technique.