Electrons of energies 125 and 150 Mev are deflected from the Stanford linear accelerator and brought to a focused spot of dimension 3 mm×15 mm at a distance of 9 feet from a double magnet deflecting system. The focus is placed at the center of a brass-scattering chamber of diameter 20 inches. Thin foils are inserted in the chamber and elastically-scattered electrons from these foils pass through thin aluminum windows into the vacuum chamber of a double focusing analyzing magnet of the inhomogeneous field type. The energy resolution of the magnet has been about 1.5 percent in these experiments. This resolution is enough to separate clearly hydrogen or deuterium elastic peaks from carbon peaks in the same scattering target. The energy loss in the foils is readily measurable. In the case of light nuclei, e.g., H, D, Be, C, the shift of the peak of the elastic curve as a function of scattering angle indicates the recoil of the struck nucleus. Relative angular distributions are measured for Be, Ta, Au, and Pb. It is possible to interpret these data in terms of a variable charge density within the nucleus.

• Received 26 June 1953

DOI:https://doi.org/10.1103/PhysRev.92.978