Resonance Scattering of Protons by Aluminum

The elastic scattering of protons by aluminum at energies near the 985-kev [based on the 440-kev $\mathrm{Li}(p,\gamma )$ voltage scale] resonance has been studied, with the use of the homogeneous proton beam available from the Wisconsin pressure generator equipped with the 90° electrostatic analyzer. The variation in the scattering yield with proton energy agrees qualitatively with the prediction of the Breit-Wigner formula. On the assumption of $S$-scattering, the data indicate a natural resonance width of the order of 100 volts.