Slow Neutron Total and Fission Cross Sections ofU233

The slow neutron total and fission cross sections of ${\mathrm{U}}^{233}$ have been measured from 0.02 ev to 200 ev on the MTR (Materials Testing Reactor) fast chopper. The strong resonances are resolved below a neutron energy of 15 ev, and show marked interference effects in the fission cross section. No resonances are observed in the total cross section which are not also present in the fission cross section, except for those attributed to the known contaminants in the samples. An estimate of the neutron strength function $〈\frac{{{\Gamma }_n}^0}{D}〉$, made by an area analysis, gives the value (1.0±0.2)×${10}^{-4\mathrm{}}$ for this energy region in ${\mathrm{U}}^{233}$.