Parameters of Neutron Resonances inTh232

The neutron widths and radiation widths of the four lowest $S$-wave resonances in thorium, $E_0=21.7,23.4,59.4,\mathrm{and} 69.1$ eV, have been measured using transmission techniques. A mean value of ${\Gamma }_{\gamma }$ of 20.1±1.3 meV is obtained for these four measurements. Using these parameters, the resonance capture integral for thorium is computed and found to be 86±6 b, in substantial agreement with recent measurements. No evidence is found for a fluctuating component of ${\Gamma }_{\gamma }$ within the experimental error. The methods of analysis, including the use of a non-Gaussian resolution function, are described.