Spin Dependence of the Thermal Neutron Cross Section ofCo59

Abstract

Transmission experiments have been carried out with polarized, monochromatic neutrons and polarized ${\mathrm{Co}}^{59}$ nuclei using a polycrystalline sample of cobalt metal. By studying the transmission as a function of temperature and neutron energy, the effects of magnetic and nuclear scattering may be separated, and the spin dependence of both the capture and scattering cross sections determined. It is found that (78.3±1.0)% of the thermal capture is into $I+\frac{1}{2}=4\mathrm{}$ states, the remainder being into $I-\frac{1}{2}$ states. This establishes the contribution of a bound level to the thermal cross section. The scattering cross section is (87±1)% due to $I-\frac{1}{2}$ states. These results are discussed in terms of the resonance structure of ${\mathrm{Co}}^{59}$.