Measurement of Fast Neutron Total Cross Sections on ^(nat)Ta and ^(nat)Bi at MeV Energy Range

The reported values of the fast neutron total cross section on ^(nat)Ta of JEFF (nuclear data in Europe) at energies below the MeV ranges are different from those of JENDL (nuclear data in Japan). Those on ^(nat)Ta and ^(nat)Bi were measured in the energy range from 0.7 MeV to 2.0 MeV by the using a time-of-flight (TOF) system and a 1.7-MV tandem-type accelerator at the Korea Institute of Geoscience and Mineral Resources (KIGAM). Fast neutrons were obtained by using the ^7Li(p,n)^7Be reaction and the ^3H(p,n)^3He reaction. The TOF system with a flight length of 4.3m consists of a time pick-up module and a plastic scintillator with a diameter of 7.54 cm and a length of 1 cm. The samples of ^(nat)Ta and natBi that were used for measuring the neutron total cross sections were cylinders with diameters of 3 cm and lengths of 1.2 cm.. A collection in the calculation of the neutron total cross section due to singly-scattered neutrons was performed by using diffraction theory based on a continuum model. The neutron total cross sections on ^(nat)Ta and ^(nat)Bi were compared with those of the evaluated nuclear data files (ENDF). KCI Citation Count: 2