Neutron Resonance Measurements of Ag, Ta, andU238

Abstract

Transmission measurements of Ag, Ta, and ${\mathrm{U}}^{238}$ cross sections have been made with a resolution of 0.17 to 0.05 μsec/meter and resonance parameters are presented in the energy region from 10 ev to roughly 300 ev. A brief description of the materials testing reactor fast chopper and its performance characteristics is included, and the resolution is demonstrated by resolving new resonances in Ta. Area analysis methods have been used with the primary objective being to determine values of $\frac{{{\overline{\Gamma }}_n}^0}{D}$. The values obtained are: ${\mathrm{Ag}}^{107}$, (0.40±0.16)×${10}^{-4\mathrm{}}$; ${\mathrm{Ag}}^{109}$ (0.82±0.4)×${10}^{-4\mathrm{}}$; ${\mathrm{Ta}}^{181}$, (1.7±0.3)×${10}^{-4\mathrm{}}$; ${\mathrm{U}}^{238}$, (1.55±0.5)×${10}^{-4\mathrm{}}$. These results agree reasonably well with values previously reported.