The absolute elastic electron-scattering cross sections of ${\mathrm{Ca}}^{40}$, ${\mathrm{V}}^{51}$, ${\mathrm{Co}}^{59}$, ${\mathrm{In}}^{115}$, ${\mathrm{Sb}}^{121,123}$, and ${\mathrm{Bi}}^{209}$ have been measured at a number of angles at a primary electron energy of 183 Mev. The cross sections were obtained by comparison with scattering from the proton. These data have been compared with the previous relative angular distributions measured by Hahn, Ravenhall, and Hofstadter. The present data are in closer agreement with the charge distributions found from fitting a Fermi two-parameter model to the older data than with those found from a fit of the Ford and Hill charge distributions. The absolute cross sections for ${\mathrm{Bi}}^{209}$ show the least agreement: they are 35% larger than the predictions of the Fermi model and about 70% larger than the Ford and Hill model.

• Received 22 August 1960

DOI:https://doi.org/10.1103/PhysRev.121.283