Proton Bremsstrahlung at 140 Mev

The high energy gamma-rays arising from 140-Mev proton bombardment of several elements has been studied using a scintillation counter telescope to detect secondary electrons. The angular distribution is consistent with an approximately isotropic distribution in the center-of-mass system if we assume the bremsstrahlung to come from $p-n$ collisions inside the nucleus. This is in disagreement with a phenomenological potential treatment of the $p-n$ force or the scalar-meson theory.