Ratio ofΓ¯n0D¯for Slow Neutron Resonances

A survey has been made of resonance parameters of the heavy elements which have been measured recently. The variation of the ratio $\frac{{{\overline{\Gamma }}_n}^0}{\overline{D}}$ with atomic weight has been compared with theoretical predictions. A maximum was found in the ratio $\frac{{{\overline{\Gamma }}_n}^0}{\overline{D}}$ at atomic weight of approximately 160 in fair agreement with the more recent theories of neutron scattering by nuclei. The experimental data, however, are not sufficiently accurate to make a choice between the new theories which have been proposed.