We report measurements and analyses of cross sections up to 40 MeV for the reactions ${}_{}{}^{89}{}_{}{}^{}(\mathit{p}$,n${)}^{89}$Zr, ${}_{}{}^{89}{}_{}{}^{}(\mathit{p}$,2n${)}^{88}$Zr, and ${}_{}{}^{89}{}_{}{}^{}(\mathit{p}$,pn${)}^{88}$Y obtained by the foil-activation method. The data are compared with other measurements and analyzed by the Hauser-Feshbach plus one- and two-step direct reactions. The analysis shows that Hauser-Feshbach plus one-step direct reaction is adequate to explain the data. The cross sections are also calculated with phenomenological preequilibrium models (exciton, hybrid, and geometry-dependent hybrid models), using global parameters. However, to get a good fit to the data with these phenomenological models, some adjustments of the global parameters were necessary. A discussion on the differences between the direct-reaction theory and preequilibrium models is given.

• Received 4 April 1988

DOI:https://doi.org/10.1103/PhysRevC.38.1624