Proton-Proton Scattering at 240 Mev by a Magnetic Deflection Method

Differential cross sections for proton-proton scattering have been measured at eight angles ranging from 171.3^∘{} to 108.1^∘{} center of mass by magnetically deflecting protons scattered by hydrocarbon and carbon targets into photographic plates placed inside the tank of the Rochester 130{''} cyclotron. The incident beam was monitored by the beta-activity induced in the target by the reaction C¹²(p,pn)C¹¹, the absolute value of the cross section being based on a 49±{}3 mb carbon cross section. The measured cross section is isotropic within statistical errors from 108^∘{} to 167^∘{}, with an average value of 4.66±{}0.39 millibarns/steradian, and increases sharply to a value of 15.8±{}1.6 mb at 171.3^∘{}. The average value of the cross section agrees with that of Oxley and Schamberger, but is in disagreement with the value obtained by Chamberlain, Segr\`e, and Wiegand.