An absolute electrostatic analyzer of deflecting angle $\frac{\pi }{2\sqrt{2}}$ radians has been used to measure and stabilize the energy of the proton beam from an air insulated electrostic generator. The following resonant energies for proton capture by some of the light elements have been measured: The high energy resolution of one thousand obtained has made accurate determination of the half-widths of these resonances possible.

• Received 26 November 1952

DOI:https://doi.org/10.1103/PhysRev.89.1283