Slow Neutron Resonances in Cesium, Palladium, and Gold

The slow neutron total cross sections of Cs, Pd, and Au have been measured with a crystal spectrometer using beryllium as a monochromator. A strong resonance was found in Cs at 5.90 ev. The strength of this resonance is ${\sigma }_0{\Gamma }^2=144\mathrm{}\pm 25$ barn ${\mathrm{ev}}^2$ with ${\sigma }_0=9500\mathrm{}\pm 2000$ barns. Pd has a strong resonance at 34.1 ev with weaker ones at 26 and 13.3 ev. The 4.91-ev resonance in Au has been found to have unusual shape. If it is a single resonance, the maximum total cross section is ${\sigma }_0=31\mathrm{}000\pm 1000$ barns and the total width is $\Gamma =0.175\mathrm{}\pm 0.01$ ev.