Neutron Resonances ofTh230

The total neutron cross section of ${\mathrm{Th}}^{230}$ has been studied from 0.05 to about 500 eV with the Argonne fast chopper. Resonance parameters are given for many of the approximately 20 resonances observed below 300 eV. The value of the $s$-wave neutron strength function, based on these parameters, is $S_0=\left({{1.3}_{-0.3\mathrm{}}}^{+0.6\mathrm{}}\right)\times {10}^{-4\mathrm{}}$. The radiation width is ${\Gamma }_{\gamma }=24\mathrm{}\pm 2$ meV. A calculation of the resonance-capture integral leads to the value 1020±30 b. Comparing this result with a direct measurement of the resonance-capture integral supports the value of 75 200 yr for the half-life of ${\mathrm{Th}}^{230}$ used in the derivation of the latter.